ChemSTEER User Guide
Chemical Screening
Exposures and Environm
^ST*%
* o \
*L pro^
Updated: May 2015
-------
ChemSTEER User Guide - Updated May 2015
Table of Contents
Table of Contents ii
Introduction 1
Background and Purpose of ChemSTEER 1
Current/Future Version Information 1
Logic and Layout Information 2
List of Current Known Issues 4
When to Use ChemSTEER 4
Inappropriate Use and Limitations of ChemSTEER 5
Sources of Methods and Models in ChemSTEER 6
About this Version and Providing Feedback 6
Getting Started 7
ChemSTEER Hardware Requirements/Software Issues 7
What You Need to Use ChemSTEER 7
General Tips and Notes for Using ChemSTEER 8
Hierarchy of ChemSTEER Operations, Activities, and Models 9
Storing and Displaying Values within ChemSTEER 16
Completing Comprehensive Assessments 18
Direct Model Access (for Advanced Users) 19
Guide to the ChemSTEER Menus 21
File Menu 21
Starting a New Assessment 21
Opening an Existing Assessment 21
Saving Your Assessment 22
Replacing the Generic Scenario Database 24
Viewing an Assessment's Revision History 24
Deleting an Assessment from the Database 25
Import/Viewing CRSS Report 26
Run Models (Advanced Users) 26
Edit 26
Cutting, Copying, and Pasting 26
Preferences 26
Setting Your Preference for the Default Database 26
Vapor Model Activation 26
ii
-------
ChemSTEER User Guide - Updated May 2015
Specifying CRSS Database 27
Reports 27
Generating and Viewing Summary Reports 27
IRER Format Details 28
Contact Report Format Details 36
Guide to Using ChemSTEER Tabs 38
General Information Tab 38
Chemical Properties Tab 41
Operations Tab 42
Define/Select Operations to be Assessed 42
Rename Default Operation Titles 44
Set the Order of Operations Within the Assessment 44
Removing Operations from the Assessment 44
Working with the Operation Subtabs 45
Operations Tab Relationships Subtab 45
Operations Tab Description Subtab 48
Operations Tab Physical States Subtab 49
Operations Tab Sources/Activities Subtab 49
Operations Tab Site Information Subtab 52
Operations Parameters Tab 53
Operation Parameters Tab Mass Balance Parameters Subtab 54
Mass Balance Basis Selection 56
Specify Mass Balance Input Parameters 56
Specify Other Batch Parameters 66
Operation Parameters Tab Container Parameters Subtab 68
Verify/Select Container Parameters 70
Verify/Select Container Parameter by Activity 74
Operation Parameters Tab Shared Parameters/Factors Subtab 75
Estimating Chemical Releases Tab 80
Estimating Chemical Exposures Tab 84
Optional Information Tab 88
Reports Tab 90
Release Sources and Exposure Activities 91
Loading Liquids into Transport Containers/Vessels 92
Unloading Liquids from Transport Containers/Vessels 94
iii
-------
ChemSTEER User Guide - Updated May 2015
Loading Solids into Transport Containers/Vessels 97
Unloading Solids from Transport Containers/Vessels 98
Cleaning Liquid Residuals from Transport Containers/Vessels 100
Cleaning Solid Residuals from Transport Containers/Vessels 105
Sampling Liquids 107
Sampling Solids 109
Equipment Cleaning Losses of Liquids 110
Equipment Cleaning Losses of Solids 112
Unit Operations and Processes 114
Vapor Release from Transfer Operations 121
Miscellaneous Sources/Activities 123
Automobile Spray Coating 126
Generic Coating Applications 129
Electroplating Bath Additives 133
Recirculating Water-Cooling Tower Additives 137
ChemSTEER Estimation Methods and Models 139
General Information on Model Parameters 139
Calculating Two Sets of Results from a Single Model 140
Environmental Releases 146
General Guidelines for Release Assessment 146
Quick Summary of ChemSTEER Release Models 147
User-Defined Loss Rate Model 156
Models for Calculating Releases to Air 161
EPA/OAQPS AP-42 Loading Model 161
EPA/OPPT Mass Transfer Coefficient Model 168
EPA/OPPT Penetration Model 174
EPA/OPPT Cooling Tower Windage Loss Model 181
EPA/OPPT Cooling Tower Evaporative Loss Model (volatiles) 183
User-Defined Vapor Generation Rate Model 184
Models for Calculating Releases to Other Media 188
EPA/OPPT Bulk Transport Residual Model 188
EPA/OPPT Drum Residual Model 194
EPA/OPPT Multiple Process Vessel Residual Model 200
EPA/OPPT Single Vessel Residual Model 205
EPA/OPPT Small Container Residual Model 211
iv
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT Solid Residuals in Transport Containers Model 217
EPA/OPPT Water Saturation Loss Model 222
EPA/OPPT Cooling Tower Blowdown Loss Model 227
EPA/OPPT Solids Transfer Dust Loss Model 229
Models for Calculating Multi-Media Releases 233
EPA/OPPT Automobile OEM Coating Overspray Loss Model 233
EPA/OPPT Automobile Refinish Coating Overspray Loss Model 238
EPA/OPPT Electroplating Rinse Water Loss Model 244
EPA/OPPT Electroplating Spent Bath Disposal Model 246
Models for Calculating Releases of Liquids 249
Releases Due to Evaporation 249
Releases During Container Filling (Vapor Displacement) 250
Releases of Residual and Waste Liquids 250
Models for Calculating Releases of Solids 250
Releases of Residual Solids 250
Worker Exposures 251
General Guidelines for Exposure Assessment 251
Quick Summary of ChemSTEER Inhalation Exposure Models 251
Quick Summary of ChemSTEER Dermal Exposure Models 262
List of OSHA PELS and NIOSH RELs 266
Models for Calculating Inhalation Exposures 267
EPA/OPPT Small Volume Solids Handling Inhalation Model 267
EPA/OPPT Mass Balance Inhalation Model 274
OSHA PEL-Limiting Model for Substance-Specific Particulates 282
OSHA PEL-Limiting Model for Substance-Specific Vapors 287
OSHA Total PNOR PEL-Limiting Model 295
OSHA Respirable PNOR PEL-Limiting Model 299
EPA/OPPT Automobile OEM Spray Coating Inhalation Exposure Model 303
EPA/OPPT Automobile Refinish Spray Coating Inhalation Exposure Model 308
EPA/OPPT Automobile Spray Coating Inhalation Exposure Model 312
EPA/OPPT UV Roll Coating Inhalation Model 315
Near-Field / Far-Field Inhalation Exposure Model 320
User-Defined Inhalation Model 324
Models for Calculating Dermal Exposures 329
EPA/OPPT 1-Hand Dermal Contact with Liquid Model 329
v
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT 2-Hand Dermal Contact with Liquid Model 335
EPA/OPPT 2-Hand Dermal Immersion with Liquid Model 340
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model 345
EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model 350
User-Defined Dermal Model 355
Models for Calculating Exposures to Liquids 360
Exposures as a Result of Evaporation 360
Exposures During Container Filling (Vapor Displacement) 360
Exposures to Mists 360
Exposures from Touching Liquid Chemicals and/or Wet Surfaces 360
Models for Calculating Exposures to Solids 361
Exposures to Dusts 361
Exposures from Touching Solid Chemicals and/or Dusty Surfaces 361
Models for Calculating Exposures Based on Exposure Limits 361
Definitions and Terms 362
Abbreviations 362
ChemSTEER Terms 373
References 375
Appendix A - Industry Specific Operations 377
Automobile Original Equipment Manufacture (OEM) Spray Coating 377
Operation tab / Description subtab 377
Operation tab / Sources/Activities subtab 378
Operation Parameters tab / Mass Balance subtab 378
Operation Parameters tab / Shared Parameters/Factors subtab 381
Releases Tab 381
Exposures Tab 381
References 381
Electroplating Bath Additive Use 382
Operations tab Description subtab 382
Operations tab / Sources/Activities subtab 383
Operation Parameters tab / Mass Balance subtab 383
Operation Parameters tab / Shared Parameters/Factors subtab 389
Releases tab 390
Exposures tab 390
References 390
vi
-------
ChemSTEER User Guide - Updated May 2015
Recirculating Water-Cooling Tower Additive Use 391
Operations tab Description subtab 391
Operations tab / Sources/Activities subtab 392
Operation Parameters tab / Mass Balance subtab 392
Operation Parameters tab Shared Parameters/Factors Subtab 396
Releases tab 396
Exposures tab 396
References 396
vii
-------
ChemSTEER User Guide - Updated May 2015
Introduction
Background and Purpose of ChemSTEER
The Chemical Screening Tool for Exposures and Environmental Releases (ChemSTEER) is a
computer-based software program developed by the U. S. Environmental Protection Agency (EPA) Office
of Pollution Prevention and Toxics (OPPT) that can be used to conduct a screening-level workplace
exposure and release assessment. ChemSTEER generates screening-level estimates for environmental
releases of and worker exposures to a chemical manufactured and used in industrial and commercial
operations (i.e. workplaces). The tool also contains data and estimation methods to assess chemical use
in common industrial/commercial sectors (e.g., automotive refinishing) and chemical functional uses
(e.g., tackifier in adhesive). ChemSTEER does not contain methods for estimating exposures to chemicals
to the general public, to consumers, or to other species in the environment.
ChemSTEER was developed for technically knowledgeable users to support the EPA in assessing
the potential exposures and risks to chemicals. A primary application is for assessing new chemicals that
are submitted to EPA under Section 5 of the Toxic Substances Control Act (TSCA). Estimates from
screening-level exposure models are not used as the sole justification for regulatory decision-making at
EPA. When available, additional information, data, and more rigorous tools are used to improve the
estimates of exposures and risks for such decisions. Another primary application is for assessing existing
chemicals, such as those chemicals covered under the High Production Volume (HPV) Program, for
which monitoring data are insufficient or unavailable. However, the use of ChemSTEER is not intended
as a substitute for the collection and reporting of environmental and human health monitoring data.
ChemSTEER's methods and models are primarily intended to assess common sources of
workplace releases and activities with worker exposure potential that are specific to a particular
industry (e.g., overspray from auto body refinishing, textile dye bath dump, etc.) and other sources of
workplace releases and activities with worker exposure potential that are "broadly applicable" across
many workplaces (e.g., drumming semi-volatile liquid, scooping/weighing small volumes of powders,
etc.). The "broadly applicable" sources/activities available in ChemSTEER are only a subset of all possible
sources and activities and cover the sources/activities that are often overlooked or considered to be
non-routine or insignificant. The methods and models in ChemSTEER have undergone internal EPA
review and most have been used extensively in EPA assessments for over 10 years.
Current/Future Version Information
The current version was developed primarily for preparing internal EPA reports on workplace
releases and exposures. EPA has included several recent improvements over initial prototypes. These
improvements are part of a continuing effort toward making ChemSTEER more "user friendly" for non-
EPA users. Improvements and changes from the last publicly available versions (July 2003 Beta and May
2004 Beta include:
• Upgraded source code from Visual Basic 6 Platform to VB.NET platform.
• Updated layout of main screens, including numbering to facilitate easier navigation.
1
-------
ChemSTEER User Guide - Updated May 2015
• Allow users direct access to specific EPA/OPPT models without starting an assessment
(see Direct Model Access (for Advanced Users)
• Additional functionality to allow users to import operations from pre-defined Generic
Scenarios or other assessments (see Import Operations)
• Addition of EPA/OPPT Solids Transfer Dust Loss Model
• Revised EPA/OPPT Automobile OEM Coating Oversprav Loss Model, EPA/OPPT
Automobile Refinish Coating Oversprav Loss Model, and the EPA/OPPT Automobile
Refinish Spray Coating Inhalation Exposure Model based on the June 2010 Emsision
Scenario Document on Coating Application via Spray Painting in the Automotive Refinish
Industry
• Updated Dermal Exposure Models for exposures to liquids according to the September
2013 updates to CEB's Method for Screening-Level Estimates of Dermal Exposure
• Revamped User Guide and Quick Start Guide
• Addition of Near-Field / Far-Field Inhalation Exposure Model
• Added/revised several Generic Scenario operations - see "What's New section of the
ChemSTEER application for complete list
EPA has the goal of developing future versions that will include additional improvements over
the current version. These improvements will continue the effort toward making ChemSTEER more user
friendly for non-EPA users. The future versions are envisioned to contain more methods (beyond
defaults), improved terminology, fixes to any issues and problems, additional industry-specific
operations and models, more output options (other text formats), and other improvements to enhance
effectiveness and efficiency of the use of the software.
Logic a tout Information
Program Purpose
ChemSTEER generates screening-level estimates for environmental releases of and worker
exposures to a chemical manufactured and used in industrial and commercial operations (workplaces).
Prerequisites
You must have a good understanding of the workplaces to be assessed (except for some specific
industries programmed as "industry-specific operations" in ChemSTEER) and have some key chemical-
and operation- specific data (e.g., vapor pressure, molecular weight, water solubility, throughput
volumes, concentrations). You must also have a good working knowledge of ChemSTEER and its
methods to generate credible results.
Brief on the Logic of ChemSTEER
The current draft version was developed primarily to meet the objective of preparing internal
EPA reports on workplace releases and exposures. The logic and layout of the program were developed
to achieve this objective.
2
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER functions by associating release sources and exposure activities expected for each
type of workplace to particular EPA methods to estimate amounts (quantities) of release and exposure.
These methods may be scientific models, empirical methods, correlations, or presumptive methods
(e.g., exposure will not exceed an OSHA PEL). Each method is based on an equation or set of equations
containing parameters related to chemical- and operation-specific factors.
The Layout of ChemSTEER
ChemSTEER is designed for you to enter input information in each tab and subtab, moving from
the top-most tab to the bottom-most tab, and left-most subtab to the right-most subtab. It is
recommended that you proceed with your assessments in this fashion, as some parameter values "flow
down" through the assessment and are used as default values in subsequent pages. In other words,
values that are entered in earlier tabs (those farther to the top) may be necessary inputs to later tabs
(those farther to the top). Within each tab, values that are entered in earlier subtabs (those farther to
the left) may be necessary inputs to later subtabs (those farther to the right). Main tabs and subtabs are
numbered for ease of navigation.
The ChemSTEER program window contains eight main input pages (views) that can be accessed
using the tabs at the left of each main page. The purpose of each of these main pages is described
briefly below.
General page (first tab) - Record and view general information about the assessment on this
page.
Chemical page (second tab) - Record and view information and data about the chemical being
assessed on this page. The information and data include chemical identity-related information,
assessment volumes, relevant physical/ chemical properties, use descriptions, and relevant regulatory
information.
Operations page (third tab) - Record and view the types of operations ("homogeneous"
workplaces - either user-defined or industry sector-specific) to assess, the immediate (direct) supplier-
customer relationship(s) each has to the other selected operations, the fraction of assessed volumes
designated for each operation, and site identification information. For each operation selected, you
must also verify or select the release sources and exposure activities. Some sources/activities are
specific to a particular industry (e.g., overspray from auto body refinishing or textile dye bath dump),
while other sources/activities are "broadly applicable" across many workplaces (e.g., drumming semi-
volatile liquid or scooping/ weighing small volumes of powders). The broadly applicable source/activities
available in ChemSTEER are only a subset of all possible sources and activities and cover those that are
often overlooked or considered to be non-routine or insignificant. Each selected source/activity
activates one or more equations that represent methods and models to quantify the release and/or
exposure estimate(s).
Operation Parameters page (fourth tab) - For each operation selected, record and view key mass
balance and container-related information used in the methods and models to estimate workplace
exposure and environmental releases. This tab also contains other model parameters that are used by
more than one release/exposure model (in the Shared Parameters/Factors subtab).
3
-------
ChemSTEER User Guide - Updated May 2015
Releases page (fifth tab) and Exposures page (sixth tab) - For each source/activity selected under
each operation included in the assessment, verify the use of the default estimation method(s) or select
another method(s). For each selected method, verify and/ or enter values for parameters used by the
selected estimation method. After ChemSTEER has generated estimates of releases or exposures for an
operation, you may combine amounts of releases from more than one source that are discharged to a
particular media on the same day. You may also combine amounts of exposures from more than one
activity that are potentially available to certain worker groups.
Optional Information page (seventh tab) - Record and view additional information relevant to
the assessment, including information related to EPA assessments, the chemical's MSDS, pollution
prevention information, general assumptions, and other information.
Reports (eight tab) - After ChemSTEER has generated release or exposure estimates, output
page views become available from the Reports screen. In these views, ChemSTEER presents a final result
overview based on the inputs, methods, and parameters selected. ChemSTEER also displays combined
releases, as well as itemized exposures on these pages after you complete all relevant data inputs and
click on the "Run Models" buttons on the Releases and Exposures tabs. Additional options available
from the output page view windows include saving the output results to a text file and printing the
results overview pages to a printer.
List of Current Known Issues
The following issues have been encountered while using the current version of ChemSTEER, but have
not been able to be reproduced consistently:
• When switching quickly between tabs and various operations, the sources and activities for
one operation may be come overlaid on to another operation. If this error is found before
the assessment has been saved, go to the "Operations" tab and click between operations
several times until the sources/activities are restored. If the assessment has been saved, the
original sources/activities will be overwritten and lost.
• When opening an assessment and viewing the "Estimating Chemical Releases" or
"Estimating Chemical Exposures" tabs, there is sometimes a "view error" where the model
parameters do not appear for the selected operation and model.
• If a set of operations is defined in a manner that creates a circular relationship, ChemSTEER
may shut down when editing certain parameters, such as shared parameters on tab 4c.
When to Use ChemSTEER
ChemSTEER should be used when release and worker exposure data are not available but some
estimates of these data are desired. Using ChemSTEER requires basic information about the chemical to
be assessed; including amounts (in kilograms) of the chemical handled and used, key physical-chemical
properties, and general information on how the chemical is manufactured, processed, and used. Using
ChemSTEER also requires a basic understanding of both the processes used at a particular workplace
(also called an "operation") and the available estimation methods within the tool.
4
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER does contain some common industrial/commercial operations (also called "generic
scenarios"), each of which is defined by a default set of processes. The operations contained in the tool
are described in more detail in the Operations Tab section.
ChemSTEER is appropriate for use as a screening-level tool to assess potential chemical
discharges to air (stack or fugitive releases), water, landfill, or incineration from operations. ChemSTEER
can also be used to estimate potential worker inhalation and/or dermal exposures to chemicals in the
operation. ChemSTEER may be run for a single type of operation or for multiple operations that may
constitute part or all of the lifecycle of the chemical in workplaces.
Inappropriate Use and Limitations of ChemSTEER
Many models in ChemSTEER are characterized by EPA to be "screening-level." Screening-level
results are intended to be conservative in that predicted results are likely to be higher, or at least higher
than average, as compared to actual releases and exposures occurring in the real world setting. Some
models in ChemSTEER, described as "what-if" models, are considered to be plausible, but whether their
results are conservative are not known. If the exposure estimated by ChemSTEER is found to result in an
unacceptably high health risk, then an appropriate next step in the assessment process is to verify
and/or refine the parameter inputs and/or to perform the assessment with different and perhaps more
complex models. Another response might be to consider monitoring to confirm results of the model.
ChemSTEER is also not appropriate for use when information about the chemical to be assessed,
including amounts (in kilograms) handled and used, several physical-chemical property parameters, and
some information on how the chemical is used are not known or well-understood. ChemSTEER is also
not appropriate when the user does not have a good technical understanding of the processes used at a
particular workplace (also called an "operation") and of the estimation methods used by the tool.
ChemSTEER does contain some common industrial/commercial operations (also called "generic
scenarios") each of which is defined by a default set of processes.
ChemSTEER does not estimate physical-chemical properties; environmental fate parameters;
exposures to the general population, to consumers, or to the environment; or releases from or worker
exposures to chemicals and products that are not covered under TSCA. If measured physical-chemical
data do not exist, commercially available estimation software can be used to estimate these properties.
Exposures to the general population, to consumers, or to the environment can be estimated using the
Exposure, Fate Assessment Screening (E-FAST) tool, which is publicly available from EPA. E-FAST may be
downloaded from the EPA Internet site at the following address:
http://www.epa.gov/opptintr/exposure.
The releases estimated by ChemSTEER are expressed as the amount of the chemical per time
discharged to various environmental media. The worker inhalation exposures estimated by ChemSTEER
are expressed in average concentrations, potential daily dose rates, and lifetime-average daily dose
rates, among others. The worker dermal exposure estimates for the chemical are also expressed as
potential daily dose rates and lifetime-average daily dose rates, among others. ChemSTEER does not
estimate absorption of the chemical by the human body.
This version of ChemSTEER contains most of the primary methods and models used by EPA.
However, many of the industry/commercial sector-specific methods and models have not been included
in this version. This version was developed specifically to meet EPA needs for assessing chemicals in
5
-------
ChemSTEER User Guide - Updated May 2015
data-sparse situations, although some considerations for external review and use of ChemSTEER were
made. EPA is interested in specific suggestions for improvements on the methods and models and on
the clarity of documentation for consideration in future updated versions. Feedback on improving ease
of use and user-friendliness may also be considered given availability of resources.
Sources of Methods and Models in ChemSTEER
The methods and models used in ChemSTEER are from several EPA sources, including the
"Chemical Engineering Branch Manual for the Preparation of Engineering Assessments" and other
reports and memoranda detailing the methods used in CEB assessments. References to the industry-
specific operations are taken from the "Chemical Engineering Branch Compilation of Generic Scenarios
for Chemical Uses." These references document the various empirical, mathematical, and suppositional
methods and models that have been developed and used by EPA over many years of workplace
exposure and release assessment.
To review a complete list of references used in ChemSTEER, go to the References section of this
User Guide.
About this Version and Providing Feedback
The most recent version of ChemSTEER and additional exposure-related information and
resources are available from the ChemSTEER home page:
http://www.epa.gov/oppt/exposure/pubs/chemsteer.htm.
This version has been developed for internal EPA use and testing. EPA has released this version
to allow interested parties to view the tool's current status, to better understand EPA's workplace
exposure assessment methods, and to provide suggestions on improving methods and models and other
features of the tool.
Over the past several years, ChemSTEER has been undergoing continuous updating as minor
features are changed and new features are added, particularly industry-specific operations (scenarios
for particular formulation or use applications). Also note that this version has received limited testing
before it became publicly available.
Any version that was found to have significant problems during testing (e.g., creates instability
on the host PC, "crashes" easily, or gives incorrect outputs) has not been released. This version has been
released because it has already been committed to routine use for generating internal EPA assessments
and reports. Among about 20 versions over the past several years, only a few prior versions have met
the standards for on-going internal use and public release.
EPA is interested in gaining feedback from non-EPA users on the usefulness of ChemSTEER. EPA
will consider specific suggestions for improving the methods and models or for improving the user-
friendliness in future updates of the tool. Please send your feedback and suggestions to the contact
listed at the bottom of the ChemSTEER home page.
6
-------
ChemSTEER User Guide - Updated May 2015
Getting Started
ChemSTEER Hardware Requirements/Software Issues
Hardware & Software Requirements
• Windows XP or above
• Processor - minimum recommended for your version of Windows
• Memory - minimum recommended for your version of Windows
• Hard disk space - minimum recommended for your version of Windows
Screen Resolution
ChemSTEER is designed for a screen resolution ofat least 1024 x 768 pixels with 96 dots per inch
(DPI) or less. You can also run ChemSTEER with a lower screen resolution or higher DPI; however, some
information and buttons will not be visible. You may not be able to navigate off of a window because
buttons may not be visible on your screen. It is not recommended to run ChemSTEER with a screen
resolution lower than 1024 x 768 pixels and higher than 96 DPI. To change your resolution, right-click on
your main Windows window, select Properties, select the Settings tab to select the desired screen
resolution, and click OK. To change your DPI, right-click on your main Windows window, select
Properties, select the Settings tab, select the Advanced button, and select your DPI setting.
What You Need to Use ChemSTEER
• Understanding of the purpose, limitations, and methods in ChemSTEER;
• Information and data (properties, amounts, and uses) about the chemical to be
assessed; and
• Site-specific information about the workplaces handling the chemical (except for some
industrial or commercial workplaces for which default information and parameters are
available in ChemSTEER).
To effectively and properly use ChemSTEER, you must first understand the purpose and
limitations of ChemSTEER. These are discussed in the Introduction section of this User Guide.
You must understand the terminology in ChemSTEER. The Definitions and Terms section of this
User Guide can be used to clarify and understand ChemSTEER terminology.
You must also understand the ChemSTEER Estimation Methods and Models used to generate
workplace exposure and release estimates. This understanding is needed to effectively determine
whether the best and most appropriate model is used for each release and exposure to be estimated.
You must have access to certain information about the chemical to be assessed. Some methods
and models used in ChemSTEER require physical-chemical property parameters. Vapor pressure, mole
fractions, densities, and water solubility are the parameters most commonly used in the ChemSTEER
models and methods. Also, you must provide the amount (in kilograms) of the chemical that is
manufactured or imported, processed or used within the scope of the assessment. When multiple
7
-------
ChemSTEER User Guide - Updated May 2015
workplace operations are to be assessed, you must provide the relationship of supplier-customer
operations and should provide a best estimate of the fraction of the amount that is devoted to each
operation assessed.
General Tips and Notes for Using ChemSTEER
You should read the User Guide thoroughly. Understanding the various functions in the software
is crucial to the effective use of ChemSTEER and its models. It is especially recommended that you
review the following sections of the User Guide:
• Chemical Properties Tab, particularly noting the required inputs;
• Operations Tab -> Relationships Subtab;
• Operations Tab -> Sources/Activities Subtab;
• Each of the subtabs within the Operations Parameters Tab; and
• ChemSTEER Estimation Methods and Models.
Pay particular attention to the bases and sources of the default values used in the above
calculations and logic, as well as where they may be used elsewhere in the assessment.
The buttons for each main screen are listed on the left side of the application and should
typically be completed sequentially. Within each screen, the user should generally complete pages
(subtabs) sequentially from left to right because some parameters' values "flow down" through the
assessment and are used as default values in subsequent pages. In other words, values that are entered
in earlier pages (those farther to left) may be necessary inputs to later pages (those farther to right).
Review the Hierarchy of ChemSTEER Operations. Activities, and Models section below for more
information.
New users may wish to review the ChemSTEER Quick Start Guide (included with this version of
ChemSTEER) and any other training guides available on EPA's website:
http://www.epa.gov/oppt/exposure/pubs/chemsteer.htm.
You should understand the File menu options for using Save and Save As to maximize
preservation of data. For example, using Save overwrites data for the assessment in the ChemSTEER
database file, while Save As saves the information to a new file. In addition, saving multiple assessments
to a single ChemSTEER database file will use less disk space than saving single assessments each to a
separate database (i.e., creating multiple ChemSTEER database files) (see Saving Your Assessment).
You may enter values in either decimal format (e.g., 5423.78 or 0.00267) or in scientific notation
(e.g., 5.42378E03 or 2.67E-03 or 2.67E-3). ChemSTEER will not accept exponential scientific notation
format (e.g., 5.42378 x 10A3 or 2.67 x 10A-3).
ChemSTEER also does not currently accept number qualifiers, such as "<" or "=>". It is
recommended that you capture information such as this in the Basis sections found wherever values are
entered. Review the Storing and Displaying Values within ChemSTEER section below for more
information.
8
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER contains several Basis text boxes located throughout the assessment in order for
you to provide additional information on the particular input values and general assumptions used in
the assessment. You are strongly encouraged to use these Basis boxes.
NOTE: Any carriage return entered within these boxes will appear as a " |" within the text when
an existing assessment is opened and viewed within ChemSTEER. These carriage returns " |" will also
appear in the reports generated by ChemSTEER.
If you wish to assess volatile releases or inhalation exposures to vapors, be sure that the
substance you are assessing has an adjusted vapor pressure within the specified range for the vapor
generation models. The default range is between 0.001 and 35 torr. If you wish to modify the range, go
to the Preferences menu and select Vapor Model Activation.
Note that the Mass Balance Inhalation Model uses some parameters from an associated vapor
generation release model as default values in calculating inhalation exposure. If you plan to use the
Mass Balance Inhalation Model, be sure to use the appropriate release model for vapor generation, and
be sure that the release model is in the appropriate place (last) on the list of release models for the
source/activity (see EPA/OPPT Mass Balance Inhalation Model).
Hierarchy of ChemSTEER Operations, Activities, and Models
ChemSTEER assessments have a hierarchical organization of operations, activities, and models.
Assessments contain one or more operations. Operations contain one or more activities. Activities may
contain one or more models.
When models are run on either the Releases or Exposures tab, all of the models within the
selected operation are run. Similarly, when Operations are analyzed in the IRER report, all of the
activities and models within each operation are processed and analyzed as a unit.
9
-------
ChemSTEER User Guide - Updated May 2015
Assessment
Dermal Exposure Model
Release Model 1
Release Model
Release Model 2
Inhalation Exposure
Model
Operation 2
Activity 1
Dermal Exposure Model
Operation 1
Activity 2
Operation 3
Activity 3
This hierarchy of operations, activities, and models has several significant implications on how
ChemSTEER operates and how interrelated elements of an assessment are affected when you make a
change:
• When Operations are deleted, all of the activities and models within the operation are
deleted.
• When an Activity is deleted, all of the models within the activity are deleted.
ChemSTEER also has an information hierarchy, as shown below. The information hierarchy is
significant because information only 'flows down' to non-user-specified parameters at lower tiers. For
example, Molecular Weight in the Chemical Information tier flows down to Molecular Weight in the
Operation Information tier (Shared Parameters) and then to Molecular Weight in the Model-Level
Information tier. Molecular Weight entered in the Operation Information tier would only flow down to
the Model-Level Information tier.
10
-------
ChemSTEER User Guide - Updated May 2015
Chemical Information
.
Operation Information: Mass
Balance Parameter & Shared
Parameters
-
Activity Information: Container
Parameters
Model-Level Information
The sections below describe how UPDATING particular parameters in an assessment affect other
parameters and functions within ChemSTEER.
Updating Total Assessed PV on the Chemical Tab or Assessed PV on the Relationships Tab
If you update the Total PV on the Chemical tab, ChemSTEER will update the Production Volume
for each Operation (PVop) based on the existing Fraction of Production Volume (PVf) for each operation
for all operations. If you update the existing Fraction of Production Volume on the Relationships tab,
the PV for the operation will be updated.
For each operation that changed PV, you must click the Update Parameters button (on the Mass
Balance Parameters subtab of the Operation Parameters tab) and click OK or Calculate remaining two
parameters in the Specify Mass Balance Input Parameters subtab. When you update the PV, ChemSTEER
will notify you that you must complete the Mass Balance Input Parameters. You will be prevented from
saving or running models until you do so.
Clicking OK or Calculate remaining two parameters will re-calculate the Mass Balance Input
Parameter values based on the new PVop using the following methods:
1. The remaining two parameters will be recalculated using current user-specified check
boxes for the five primary mass balance parameters (shown in the Specify Mass Balance
Input Parameters subtab).
2. Any of the other mass balance parameters (displayed at the bottom of the Specify Mass
Balance Input Parameters subtab) that are not user-specified will be recalculated using
the updated PVop.
11
-------
ChemSTEER User Guide - Updated May 2015
3. If you have a batch operation and the number of batches per year (Nby) has changed
because of the new PVop, the non-user-specified daily batch parameters on the Specify
Other Batch Parameters subtab will be re-calculated.
See the Updating Mass Balance Values section below for more information on updating
calculated values.
Updating Chemical Vapor Pressure (VPchem) and Molecular Weight (MW) on the Chemical
Tab
The vapor pressure (VPchem) and molecular weight (MW) from the Chemical tab are used by
certain models, as well as in the calculations performed on the Shared Parameters subtab of the
Operation Parameters tab (e.g., VPchem is used in the calculation of AVPlow and AVPhigh; MW is used
in the calculation of the mole fractions (i.e., Xrm, Xprod, or Xother) using Raoult's law).
When you update VPchem and/or MW in the Update Chemical Information window and click
the OK button, all non-user-specified values of VPchem and MW are automatically overridden in any
model that utilizes these parameters.
In addition, the values of AVPlow and AVPhigh are updated for the new VPchem and mole
fractions calculated by Raoult's law are re-calculated using the new MW.
The release and exposure models will also need to be re-run to reflect the updated values in
VPchem, MW, and the mole fractions.
NOTE: The original default models for the sources/activities will not be changed, even if a
model-defaulting conditional parameter has been changed as a result of the update. For example, if the
original VPchem and resulting AVPprod were within the preferred AVPrange, then the Loading Liquid
Product into Drums source/activity included the EPA/OAQPS AP-42 Loading Model as a default for
calculating releases to air. If you then modify the VPchem such that the resulting AVPprod is now below
the preferred AVPrange, the EPA/OAQPS AP-42 Loading Model remains associated with the loading
source/activity (in a new assessment, if AVPprod were less than the preferred AVPrange, the
EPA/OAQPS AP-42 Loading Model would not have been defaulted). You must remove the air release
model manually if you no longer wish to assess volatile releases to air from the source/activity.
Refer to the following User Guide Topics for more information:
• Vapor Model Activation
• Operation Parameters Tab -> Shared Parameters/Factors Subtab
• Default Model Processing
Updating the Chemical Solubility in Water (WSchem) on the Chemical Tab
The chemical water solubility (WSchem) from the Chemical tab is not used in the Mass Balance,
Container Parameters, or Shared Parameters subtab calculations (all within the Operation Parameters
tab); however, it is used by some models. When you update WSchem and click the OK button in the
Update Chemical Information window, all non-user-specified values of WSchem are automatically
overridden in any model that utilizes WSchem in its calculations.
12
-------
ChemSTEER User Guide - Updated May 2015
The release and exposure models will need to be re-run to reflect the updated value in the
model outputs.
Updating Chemical Density (Dchem) on the Chemical Tab
The chemical density (Dchem) is used in the Container Parameters subtab calculations (of the
Operation Parameters tab). When you update Dchem and click the OK button in the Update Chemical
Information window, Dchem automatically updates default densities in the Container Parameters input
subtabs. In the Verify/Select Container Parameters by Source/Activity subtab, you should verify all user-
specified container parameters and click the Calculate the remaining two values button or the Restore
Defaults button to recalculate container parameters based on the new Dchem. See updating "Container
Parameter Values" below.
Updating Mass Balance Values
Clicking Calculate remaining two parameters on the Specify Mass Balance Input Parameters tab
will re-calculate the "other" three mass balance parameters (displayed at the bottom of the Specify
Mass Balance Input Parameters subtab) and the daily batch parameters on the Specify Other Batch
Parameters subtab (if a Batch basis is selected for the mass balance calculations) according to the
following rules:
• If none of the "other" mass balance parameter values and/or the daily batch parameter
values are user-specified, those will be updated according to the default logic.
• If two of the "other" mass balance parameter values are user-specified, the third value
will remain unchanged. You should re-verify those values.
• If only one of the "other" mass balance parameter values is user-specified, ChemSTEER
will re-default the second value based on the primary five mass balance parameter
values (shown at the top of the subtab), and will recalculate the third value based on the
user-specified and re-defaulted value. It is recommended that you verify the user-
specified "other" mass balance parameter value.
Clicking OK will return you to the Operations tab. NOTE: You may receive error messages to
resolve mass balance discrepancies (e.g., the calculated operating days per year exceeds 365).
When you make updates to Mass Balance Parameter values and click the OK button (on the
Update Operation Mass Balance Parameters window), the affected non-user-specified Container
Parameter values are automatically recalculated. Note that in order for all Container Parameter values
to be calculated, you must specify at least the appropriate Weight Fraction and the Number of Sites on
the Mass Balance Parameters subtab. When user-specified container parameters are used, you should
verify that the user-specified container parameters are still applicable and click the Calculate the
remaining two values button to eliminate any possible discrepancy. For example, operating days (ODa)
may have been calculated based on three other user-specified container parameters to be 100 dpy;
however, because ODa is not user-specified, changing OD to 250 dpy on the Mass Balance parameters
subtab would cause ODa on the Container Parameters subtab to update to 250 dpy, causing a
discrepancy between the three user-specified container parameters.
Any non-user-specified model value associated with the modified Mass Balance parameter is
automatically overridden in any model that utilizes the modified parameter in its calculations. The
13
-------
ChemSTEER User Guide - Updated May 2015
release and exposure models will need to be re-run to reflect these updated values in the model
outputs.
Note: if you change Yprod in an operation and Yprod is used as the default value for Yrm in a
subsequent operation, the Yrm will not be updated to the modified Yprod value from the previous
operation - Be sure to click the Restore Defaults button in the subsequent operation(s) Mass Balance
Parameter screen to allow the Yrm to be automatically updated with a modified Yprod from the
previous operation. The release and exposure models in the subsequent operation will also need to be
re-run to reflect the updated value in the model outputs.
Updating Container Parameter Values
On the Container Parameters subtab, when user-specified container parameters are used in the
Verify/Select Container Parameters by Source/Activity subtab and changes are made that affect the
other parameters used in the calculations, you should verify that the user-specified container
parameters are still applicable and click the Calculate the remaining two values button to eliminate any
possible discrepancy between the parameters in the two Container Parameters subtabs.
When you make updates to container-related source/activity parameters in the Container
Parameters subtab and click the OK button (on the Update Container Parameters window), all non-user-
specified, container-related model parameter values are automatically overridden in any model that
utilizes them in its calculations.
The release and exposure models will need to be re-run to reflect these updated values in the
model outputs.
Updating Shared Parameter Values
When you make updates to a value on the Shared Parameters subtab and click the OK button
(on the Update Shared Parameters window), all non-user-specified, shared parameter model values are
automatically overridden in any model that utilizes them in its calculations.
The release and exposure models will need to be re-run to reflect these updated values in the
model outputs.
Updating Vapor Generation Rate Model Equation Parameters
When the release of a volatile chemical is assessed in ChemSTEER, the release model calculates
a vapor generation rate (G). This parameter is then used to calculate the daily release of the chemical to
air. To read more about these types of release models, go to the Models for Calculating Releases to Air
section of this User Guide.
The G parameter, as well as other model input parameters such as hours per day, that are
calculated or set in the selected release model are then passed to and used by the EPA/OPPT Mass
Balance Inhalation Model to calculate the corresponding worker exposure to the chemical vapor on the
Exposures tab. If you change any of the input parameters for the air release model, you should re-run
the release models in order to recalculate the G parameter. This will ensure that the most current input
parameter values are passed to and utilized by the inhalation exposure model.
14
-------
ChemSTEER User Guide - Updated May 2015
Review the Calculating Two Sets of Results from a Single Model section to read more about how
the two sets input parameters (i.e., used to calculate Output 1 and/or Output 2 results) for each of the
air release and inhalation exposure models work together.
Default Model Processing
The sources/activities in ChemSTEER typically have one or more default release and/or exposure
models associated with them. These default models may be conditional based on the input data values
in the assessment. Default Model Processing (DMP) is the function in ChemSTEER that adds default
models to the source/activity based on the conditions in the assessment.
For more information on which models are defaults for each source/activity, see Release
Sources and Exposure Activities.
Default release models are selected for each source as soon as you select the operation on the
Releases tab. Similarly, the default exposure models are selected for each activity when you select the
operation on the Exposures tab. The default release and exposure models are added to each
source/activity within an operation only once in an assessment. Once the operation is selected, any of
the sources/activities within that operation that have not already been processed for Default Models will
be processed to determine which default models are appropriate for each source/activity.
Once a source/activity has been 'processed' and the default models are set, that source/activity
will not be 'processed' again. In other words, the original default models will not be changed, even if a
conditional parameter has been revised. For example, if a vapor-generation model was selected by
default as a result of the AVPIow/AVPhigh values, that model will not be de-selected if the parameter
values are subsequently changed such that the VP for the chemical is less than AVPlow or greater than
AVPhigh.
However, if new sources/activities are added to an operation, they will be 'processed' for
default models based on the current criteria such as the AVPlow to AVPhigh range. This is true even if
the operation contains sources/activities that were previously 'processed'.
The 'status' of Default Model Processing for each source/activity is shown on the
Sources/Activities subtab located on the Operations tab. The Release DMP displays the status of the
source/activity's release models and the Exposure DMP displays the status of the source/activity's
exposure models. The four values for DMP are:
Pending DMP has not yet been done on the source/activity
Cond Models Added DMP has been done on the source/activity and conditional
models were added
Cond Models Not Added DMP has been done on the source/activity and conditional
models were not added
No Cond Models DMP has been done on the source/activity but it had no
conditional models
You can always change default release or exposure models that ChemSTEER has chosen for a
given source/activity. If you would like to either remove a model or replace a chosen model with a
15
-------
ChemSTEER User Guide - Updated May 2015
different model, click the Add or Remove a Model button on the Releases or Exposures tabs, as
appropriate.
If you would like ChemSTEER to re-default models based on new conditions for a source/activity
that has already been processed, in the Update Sources/Activities window on the Operations tab /
Sources/Activities subtab you can:
1) Change the Release and/or Exposure status from Yes to No, click OK, and then return the
status to Yes, or
2) Remove the activity from the list and then add the activity back to the list.
NOTE: either one of these methods will cause any user-specified values and outputs to be lost.
You will need to re-enter any values that you had entered previously.
Storing and Displaying Values within ChemSTEER
Dates
ChemSTEER uses the MM/DD/YYYY format for dates.
Rounding of Numbers
1. If the digit to the right of the "rounding digit" is less than 5, the rounding digit is not
changed but all digits to the right of it are dropped.
2. If the digit to the right of the "rounding digit" is greater than or equal to five, one is
added to the rounding digit and all digits to the right of it are dropped.
3. When ChemSTEER rounds using the Scientific Notation function (described below), the
display of your calculated or entered value may change; however, the exact value will
still be retained in ChemSTEER and used in subsequent calculations
Exception: if a field is designated as a whole number (non-negative integer) and a decimal value
is calculated, ChemSTEER will round any value below 1 to 1. For example, on the Mass Balance tab, if the
Number of Sites (NS) is calculated based on other values to be 0.2, ChemSTEER would change NS to 1,
but display a warning for an apparent mass balance discrepancy.
Display of Numbers using Scientific Notation/Significant Digits
User-Entered Values
Most user-entered values are saved as "Single" data types to save disk space and because users
are not expected to enter values with an excessive level of accuracy. For these user-entered cases,
ChemSTEER will convert the number to a Single data type. The General Number form typically stores
and displays values as entered; however, Microsoft Access generally limits stored values to 8 characters
(including the decimal point, but excluding the leading zero before a decimal point and the scientific
notation E-00).
16
-------
ChemSTEER User Guide - Updated May 2015
For example, if you enter 300.001 for MW on the Chemical tab, ChemSTEER will save and use
that value. However, if you enter 300.345678, ChemSTEER will convert that value to 300.3457. Likewise,
an entered VP of 0.000012345678 will be converted to 1.234568E-05.
Calculated Values
ChemSTEER uses Single data types for calculated values. While ChemSTEER retains and uses the
calculated values, the following rules (Scientific Notation function) are invoked for display purposes:
1) Numbers that are required to be non-negative integers (e.g., NS) are displayed as whole
numbers.
2) All other numbers typically are displayed using the following rules:
• If the number if > 100, it is displayed with the format of ###,##n.##
(e.g., 190.1 displays as 190.1, 190.001 displays as 190, 5 million displays as
5,000,000)
• If the number is > 0.1 and <= 100 then it is displayed as ###,##n.####
(e.g., 90.01 displays as 90.01, .55555 displays as 0.5556)
• If the number if > 0.01 and <= 0.1 then it is displayed as 0.###
(e.g., 0.055555 displays as 0.056)
• If the number is > 0.1E-15 and <= 0.01 it is displayed as O.OOOOE-nn
(e.g., .00555555 displays as 5.5556E-03)
Note: "#" will cause any leading or trailing zeros to be removed; "n" displays the numeric digit
even if it is zero.
The following table shows when the Scientific Notation function is used.
17
-------
ChemSTEER User Guide - Updated May 2015
Window/Tab
Usage of Scientific Notation Function
Chemical tab
No
Chemical Update Window
No
Operations Parameters (Relationship tab)
Yes (however, Pvop for the current operations will not display if <
0.001)
Operations Parameters (Relationships update
window)
No
Mass Balance tab
Yes (except for parameters that are required to be integers, like
OD, NS, LS, etc.; and Nbld, which is set to one fixed digit after the
decimal point)
Mass Balance update window
No
Container Parameters tab
Yes
Container Parameters update window
Yes (except when Restore Defaults is used)
Shared Parameters tab (X/A VP)
Yes
Shared Parameters update window (X/A VP)
No
Release Model Input Parameters tab
No
Release Model Input Parameters update
window
No
Exposure Model Input Parameters tabs
No
Exposure Model Input Parameters update
window
No
Exposure Model Output tab
Yes
Completing Comprehensive Assessments
To use ChemSTEER effectively and efficiently, you should enter all information and parameters
that cause ChemSTEER to populate default parameters' values for the models that you plan to use.
You should generally enter information and data within each page from left to the right. This is
because some parameters values in tabs to the right originate or are calculated from parameter values
in earlier (left) tabs. The following process is generally recommended for most new assessments:
Initiate ChemSTEER, or if you are viewing or using an assessment, save that assessment if
desired, then click File/New Assessment, which will clear all information and data entered in the
previous assessment from all views. Begin by entering any information that you may want to record on
the General tab. You should be sure to enter an Identifier.
Click on the Chemical tab and enter assessment volume(s) and chemical properties parameters'
values.
Click on the Operations tab and first select all operations to assess. This selection is completed
on the window accessed using the Update Operations button. Then for EACH operation selected and in
the order selected, complete the data fields for each of the subtabs as they are ordered from left to
18
-------
ChemSTEER User Guide - Updated May 2015
right (Relationships, Description, Physical States, Source/Activities, and Site Information). Note: you may
include up to 20 sources/activities within each operation that is assessed in ChemSTEER.
Click on the Operation Parameters tab.
For EACH operation, enter the Mass Balance subtab parameters accessed using the Update
Parameters button. Then click on the Container Parameters subtab.
For EACH operation, view the Container Parameter subtab parameters in each of the subtabs as
they are ordered from left to right (For Raw Materials, For Other Materials, For Product, and Container
Parameters by Activity). If you wish to change any of the parameters' values, double-click on the
appropriate Source/Activity name and make the change. Finally, click on the Shared Parameters/Factors
subtab.
For EACH operation, review the model parameters that are shared between more than one
model. Currently, this subtab allows you to adjust the vapor pressure of the raw material, product, or
other material. You can also select parameters for the Automotive Spray Coating models in this subtab.
Click on the Releases tab. For each Operation, check each Release Activity first by determining
whether the Release Models are those that you want to use. Change models if desired, and then for
each Model check the parameters used in the models and, if needed, click the View/Update Model
Information button to change any parameter values that need to be updated. Click Run Model(s) and
click on the Estimated Releases subtab to view model outputs. You may change the medium/media of
release by clicking on the Modify Media of Release button.
Click on the Exposures tab. For each Operation, check each Exposure Activity first by
determining whether the Exposure Models are those that you want to use. Change models if desired,
and then for each Model check the parameters used in the models and, if needed, click the View/Update
Model Information button to change any parameter values that need to be updated. Click Run Model(s)
and click on the Estimated Exposures subtab to view model outputs.
Click on the Optional Information tab and enter any relevant information for any topic in the
combo box.
Save your assessment. If you cannot finish the assessment in one sitting, you may Save the
assessment at any point in its development, then later Open the assessment and continue where you
had stopped.
Note: Be sure to use the Basis buttons to document key assumptions and data and to explain
use of non-default values, particularly in the various update windows accessed from the Operation
Parameters, Releases, and Exposures tabs.
Direct Model Access (for Advanced Users)
This version of ChemSTEER has been developed to allow you to access specific environmental
release or occupational exposure models directly from the Splash Screen or Menu bar. To access this
function, click on the "Run Exposure/Release Models (Advanced Users)" on the splash screen or through
19
-------
ChemSTEER User Guide - Updated May 2015
File/Run Models (Advanced Users) on the menu bar. It is recommended that you familiarize yourself
with each model - see the following sections for a summary of each model:
• Quick Summary of ChemSTEER Release Models
• Quick Summary of ChemSTEER Inhalation Exposure Models
• Quick Summary of ChemSTEER Dermal Exposure Models
When the option is selected a popup screen allows you to select a single model from one of
three categories: "Release Models", "Dermal Exposure Models", or "Inhalation Exposure Models". Once
you have selected a model, click the Ok button. This takes you directly into ChemSTEER, directly to the
appropriate "View/Update Model" screen. ChemSTEER will automatically set the model's parameter
types to non-default. The user will be able to immediately enter parameter values and run the model as
normally done during an assessment.
Once the selected model's parameters have been entered and the model has been run, the
estimated releases or exposure will be available for viewing on the regular ChemSTEER screens. The user
then has the option of preparing an assessment. If you wish to run a different model, you can select
File/Run Models (Advanced Users)" from the file menu.
Note: For release models, the error message indicating that the release exceeds the PV will not
be suppressed since users of this function are expected to be advanced and to avoid potential issues if
the assessment is saved.
20
-------
ChemSTEER User Guide - Updated May 2015
Guide to the ChemSTEER Menus
File Menu
Starting a New Assessment
You may choose File/New Assessment to clear all ChemSTEER fields of a working assessment.
Choosing New Assessment removes all data elements (selected operations and sources/activities; all
parameters and associated information; and model estimates) from the ChemSTEER interfaces (i.e.,
screen views shown on your monitor) and from the ChemSTEER working assessment databases. This
removed data and information cannot be retrieved unless it was saved to a file prior to choosing New
Assessment.
Opening an Existing Assessment
You may select File/Open Assessment to retrieve a previously saved Assessment (record) from
an existing ChemSTEER database file.
If the existing database file contains only one Assessment record, the information in that record
will appear in the ChemSTEER interface (screen views shown on your monitor).
If the existing database file contains more than one Assessment record, a table of Assessment
records will appear that includes six fields in the record: Type, Fiscal Year, Identifier, Consolidated Case,
Status, and Date. You may click on any of these fields or on the gray rectangle to the left of the 'Type'
field in the row of the Assessment record that you wish to open. This will cause an arrow to appear in
the gray rectangle in the row of Assessment record that you wish to open. Once this arrow is in the row
of Assessment record that you wish to open, clicking on the Open button will cause the information in
that record to appear in the ChemSTEER interfaces.
You may also use the Search button to filter available assessments by one or more of the
following parameters: Assessment ID, Assessment Type, Assessment Status, or Date Range. If you wish
change your selection criteria, you can delete entered text from the Assessment ID and Date Range text
boxes and hit the reset button(s) to clear the Assessment Type and/or Assessment Status drop-down
box(es).
Opening Assessments Created in an Earlier Version of ChemSTEER
ChemSTEER allows you to open and modify assessments that were originally created and saved
with an earlier version of the software. Any assessment that was created with the December 2003
version of ChemSTEER or later may be opened, reviewed, and/or modified using the current version.
Note: The December 2003 version of ChemSTEER was created for internal testing/use and was not
released to the public.
If you make changes to the previous assessment and wish to save these changes, you must
select the File menu and click Save Assessment As to save it to the current version of the ChemSTEER
database. You must also update the assessment to the current version of the database prior to running
reports. See the Saving Your Assessment topic of the User Guide for more information.
21
-------
ChemSTEER User Guide - Updated May 2015
Attempting to Open an Assessment Using an Older Version of ChemSTEER
ChemSTEER will not allow you to open an assessment that was last saved in a more recent
version of the software. For example, an assessment saved in an April 2, 2004 version of ChemSTEER
may not be opened using a December 2003 version of the software. If you attempt to open a more
recent assessment using an older version of the software, you will receive the following error message:
"Version Error: You have opened an assessment that was created in the [date] version
of ChemSTEER. This is not permitted. Please use the later version of ChemSTEER to open
this assessment."
Note: The December 2003 version of ChemSTEER was created for internal testing/use and was
not released to the public.
Savit
You should save your assessments frequently throughout their development. ChemSTEER has no
automated backup feature, and saving frequently is one way to protect your data due to unanticipated
program shutdown or power loss.
Assessments may be saved as individual records in a database file containing multiple records or
as their own individual database files.
If you open an assessment (record) from an existing database file, you may view and/or edit the
assessment on the ChemSTEER interfaces (screen views).
You may choose File/Save Assessment to overwrite the assessment that is in the existing
database file with the working assessment that is displayed on the ChemSTEER interfaces; however, if
the identifying fields in the current assessment are identical to the identifying fields of an assessment
already in the database file, ChemSTEER will display the following message box:
"A duplicate assessment exists in the database. Do you want to replace the existing
assessment with the current assessment? If not, you must change at least one
Identifying Field."
Alternately, if you changed any of the identifying fields in the assessment since the last time you
saved, ChemSTEER will display the following warning:
"You have changed an Identifying Field since your last save and continuing with the save
will overwrite your existing assessment. If you wish to create a new assessment, you
should Cancel and use Save Assessment As."
For a discussion of identifying fields, please see the General Information Tab topic.
NOTE: To save the assessment, click the Save button in the Save Assessment As dialog screen.
22
-------
ChemSTEER User Guide - Updated May 2015
Saving Assessments before Mass Balance Parameters Have been Updated
If you have updated the PV or imported an operation into ChemSTEER, you are required to
update the Mass Balance Parameters before saving. If you have not updated your mass balance
parameters, you will receive a warning message when you attempt to save the assessment.
Saving Assessments Before All Models Are Run
If you have sources/activities included in your assessment and you have either never run the
associated release or exposure models or have made changes to the settings or parameter values used
by any of the selected models, you will receive a warning message when you attempt to save the
assessment.
The warning message will display the models that are not current (i.e., have not been run). You
may choose to:
1. Run All Models - this option will cause ChemSTEER to proceed in running all of the
models with their current settings and parameter values and save the assessment.
2. Continue without Running All Models - this option will cause ChemSTEER to save the
assessment without running the models.
3. Cancel Action - will remove the "request" to save the assessment and will return you to
your assessment.
Saving a Revised Assessment with a New Name
Alternately, you may choose File/Save Assessment As to create a new assessment record (i.e.,
the working assessment that is displayed on the ChemSTEER interfaces) either in an existing database
file or a new database file. Save Assessment As prevents ChemSTEER from overwriting an existing
assessment record that was retrieved from the existing database file and edited, however, if the
identifying fields in the current assessment are identical to the identifying fields of an assessment in the
destination database, ChemSTEER will display the following message box:
"A duplicate assessment exists in the database. Do you want to replace the existing
assessment with the current assessment? If not, you must change at least one
Identifying Field."
For a discussion of identifying fields, please see the General Information Tab topic.
When using File/Save Assessment As, ChemSTEER defaults the database save name according to
the following convention:
[Assessment Type][Fiscal Year]-[Assessment ldentifier]"C"{if the Consolidated Case =
Ves} [Status]
NOTE: To save the assessment, click the Save button in the Save Assessment As dialog screen.
Saving Changes to an Assessment Created by an Earlier Version of ChemSTEER
23
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER allows you to open and modify assessments that were originally created and saved
with an earlier version of the software. Any assessment that was created with the December 2003
version of ChemSTEER or later may be opened, reviewed, and/or modified using the current version.
Note: The December 2003 version of ChemSTEER was created for internal testing/use and was not
released to the public.
If you make changes to the previous assessment and wish to save these changes, you must
select the File menu and click Save Assessment As to save it to the current version of the ChemSTEER
database. You must also update the assessment to the current version of the database prior to running
reports.
If you click either File/Save Assessment or attempt to run a report before first saving the
previous assessment to a current database, ChemSTEER will display the following warning:
"Version Warning: You have opened an assessment that was last saved in a previous
version of ChemSTEER. You will need to do a Save Assessment As before running
reports."
Attempting to Save to a Full Disk
Each time you save your assessment, ChemSTEER checks your target location to determine if
you have enough disk space for the assessment. If you try to save to a location with less than 2
megabytes (MB) of available space, ChemSTEER will display the following message:
"You have selected a save location with inadequate space for this assessment. Please
select an alternative location (with more than 2 MB of available space) to save the
assessment."
If you see this message, you must select another location to save the assessment.
Replacing the (
This version of ChemSTEER comes with a "scenarios.epa" database, which includes the Generic
Scenario Operations available in the assessment. Periodically, EPA may distribute an updated database.
To update your Generic Scenarios database, save the new "scenarios.epa" database to your hard drive,
click on File/Replace Generic Scenario Database, and select the new "scenarios.epa" file.
Viewins
You can save changes to an assessment without updating the "Date" field in the General tab.
Each time you open an assessment and close it (with or without saving), the date/time of the
ChemSTEER database file is updated. As a result, it may often be difficult to determine WHEN a
particular assessment was last modified and saved.
To view the revision history of the current assessment (i.e., the open assessment in
ChemSTEER), go to the File menu and click Revision History. This will activate the Display Revision History
24
-------
ChemSTEER User Guide - Updated May 2015
of the Assessment screen, which contains a table of records for each time the current assessment was
saved. Each record contains the following information, as recorded at the time the assessment was
saved:
• Saved On - contains the date and time of the save (the save records are ordered by
descending date/time);
• EPA ID - Assessment Identifier from the General tab;
• CBI - CBI indicator (Yes/No) from the General tab;
• Type - Assessment Type from the General tab;
• Status - from the General tab; and
• Fiscal Year-from the General tab.
The General Information Tab topic contains a more detailed description for each of the
identifying fields listed above.
Go to Saving Your Assessment for more information on how to save your assessment.
Dele; i the Database
You may select File/Delete Assessment to delete a previously saved assessment from a
ChemSTEER database. ChemSTEER will display a navigation window for you to choose the database in
which the assessment to be deleted is saved. Select the database and click OK.
If the database file contains only one Assessment record, ChemSTEER will delete that
assessment automatically.
If the existing database file contains more than one Assessment record, a table of Assessment
records will appear that includes six fields in the record: Type, Fiscal Year, Identifier, Consolidated Case,
Date, and Status. You may click on any of these fields or on the gray rectangle to the left of the 'Type'
field in the row of the Assessment record that you wish to delete. This will cause an arrow to appear in
the gray rectangle in the row of Assessment record that you wish to delete. Once this arrow is in the row
of Assessment record that you wish to delete, clicking on the Delete button will cause that assessment
to be deleted from the database.
You may also use the Search button to filter available assessments by one or more of the
following parameters: Assessment ID, Assessment Type, Assessment Status, or Date Range. If you wish
change your selection criteria, you can delete entered text from the Assessment ID and Date Range text
boxes and hit the reset button(s) to clear the Assessment Type and/or Assessment Status drop-down
box(es).
NOTE: You may not delete an assessment that is currently opened in ChemSTEER. If you attempt
to delete an open assessment, ChemSTEER will display a warning message asking you to first close the
open assessment. To close an assessment, choose File/Close Assessment.
25
-------
ChemSTEER User Guide - Updated May 2015
Import/Viewing CRSS Report
These options are for internal EPA use.
\i Models (Advance
This menu option runs the Direct Model Access (for Advanced Users).
Edit
ng, Copying, and Pasting
These features work similarly to the corresponding features in other Windows-based programs.
Preferences
Settii , - ¦ 1 :¦ • ' ¦ ¦ tabase
You may click on the Preferences menu and select Default Database to view and change your
default ChemSTEER database file. This default file will be the first file that ChemSTEER will use when
using the File/Open Assessment and File/Save Assessment options from the Windows menu. To change
the default file, you may click on the Browse button and use the navigation window that appears to
select a ChemSTEER database file.
Vapor Mode! Activation
You may click on the Preferences menu and select Vapor Model Activation to view or change the
default adjusted vapor pressure range that is used to activate vapor models in subsequent new
assessments. Each assessment will have its own, possibly unique, adjusted vapor pressure range. For any
new assessment, the adjusted vapor pressure range in the Preferences/Vapor Model Activation menu
item is the default for the adjusted vapor pressure range on the Operation Parameters tab, Shared
Parameters/Factors subtab.
Following this initial defaulting, the adjusted vapor pressure range for the current assessment
can only be changed on the Shared Parameters/Factors subtab. The adjusted vapor pressure range
determines whether or not ChemSTEER selects vapor generation release and mass balance inhalation
models as defaults in the assessment for many of the release sources/inhalation exposure activities for
liquids. By changing the value(s) of the adjusted vapor pressure range (AVPlow and/or AVPhigh), you
change when ChemSTEER will select the vapor generation release and mass balance inhalation models
as defaults for the liquid release sources/inhalation exposure activities.
When a new assessment is created, its initial adjusted vapor pressure range (AVPlow and
AVPhigh) is based on the adjusted vapor pressure range default for that workstation on which
ChemSTEER is being run. A workstation's adjusted vapor pressure range can be changed by using the
Preferences/Vapor Model Activation menu option. Changing the default adjusted vapor pressure range
on the Preferences/Vapor Model Activation menu option only affects the default for that workstation.
26
-------
ChemSTEER User Guide - Updated May 2015
The workstation's default adjusted vapor pressure range is set to the ChemSTEER default values when
ChemSTEER is installed. It is generally recommended that the following settings be made:
AVPlow = 0.001 torr and
AVPhigh = 35 torr.
These are the default values for ChemSTEER. Clicking the Restore Defaults button resets AVPlow
and AVPhigh to these ChemSTEER default values.
ChemSTEER calculates several adjusted vapor pressures for each operation. These adjusted
vapor pressures (AVPrm, AVPprod) may be viewed on the Operation Parameters tab, Shared
Parameters/Factors subtab. ChemSTEER selects the calculated adjusted vapor pressure that is
appropriate for each liquid release source/inhalation exposure activity and compares the AVP to the
adjusted vapor pressure range in the Shared Parameters/Factors subtab.
If the AVP for the source/activity is within the adjusted vapor pressure range shown in the
Shared Parameters/Factors subtab, then ChemSTEER will select the appropriate vapor generation
release and mass balance inhalation models as defaults for the source/activity.
If the AVP for the source/activity is outside of the adjusted vapor pressure range shown in the
Shared Parameters/Factors subtab, then ChemSTEER will not select any of the vapor generation release
or mass balance inhalation models as defaults for the source/activity. It is recommended that other
vapor generation and inhalation methods (e.g., monitoring data for the assessed chemical or an
appropriate surrogate chemical) be used when adjusted vapor pressure is below 0.001 torr or above 35
torr.
Specifyii S Database
You may click on the Preferences menu and select Specify CRSS Database to view and change
your default CRSS database file. Note that this is for internal EPA use.
Reports
Generating and Viewing Summary Reports
Go to the Reports menu or tab to view and print or export a copy of the EPA-formatted Initial
Review Engineering Report (IRER) and/or Contact Report from the working assessment.
The IRER is a specially formatted EPA report for internal use for summarizing estimates of
workplace releases and exposures in a particular assessment. See the IRER Format Details section for
more information.
The Contact Report summarizes the information obtained via an external contact. See the
Contact Report Format Details section for more information.
Clicking on the Reports menu or tab and selecting View IRER Report, View Contact Report, or
View Combined IRER & Contact Report will display the report in a view window from which you may
print the report. You may also export the report directly into *.txt, *.pdf, or *.rtf formats to a choice of
27
-------
ChemSTEER User Guide - Updated May 2015
destinations (e.g., disk) using the Save IRER Report, Save Contact Report, or Save Combined IRER &
Contact Report options.
To view various pages of the report, click on the appropriate arrow icons on the menu bar of the
view window.
To print the report, click on the printer-shaped icon on the menu bar of the view window.
To export the report, click on the envelope-shaped icon on the menu bar of the view window.
NOTE: When you attempt to export an IRER without completing the Occupational Exposure
Rating & the Consumer Use in the Physical State and Misc CRSS Info, Other Uses, Occupational
Exposure Rating, and Consumer Use input screen of the Optional Information Tab, ChemSTEER
will display a warning message. You may click Yes to continue with the export without the
exposure rating or the consumer use. Click No to cancel the export.
ChemSTEER contains several Basis text boxes located throughout the assessment in order for
you to provide additional information on the particular input values and general assumptions used in
the assessment. You are strongly encouraged to use these Basis boxes. Note: any carriage return
entered within these boxes will appear as a " |" within the text when an existing assessment is opened
and viewed within ChemSTEER. These carriage returns " |" will also appear in the reports generated by
ChemSTEER.
The IRER and Contact Report use the database fields from the currently selected assessment
within ChemSTEER. You are required to save the current assessment before running reports for new
assessments or modified assessments (including re-running models). You must also have at least one
operation in order for saved data to be displayed in the IRER report. See the User Guide topics, IRER
Format Details and Contact Report Format Details, for more specific information about these reports.
Generating or Exporting Assessment Reports Before All Models Are Run
If you have sources/activities included in your assessment and you have either never run the
associated release or exposure models or have made changes to the settings or parameter values used
by any of the selected models, you will receive a warning message when you attempt to generate or
export the assessment, asking you to save your assessment first (see Saving Your Assessment).
IRER Format Details
The Initial Review Engineering Report (IRER) is a specially formatted EPA report for internal use
in summarizing estimates of workplace releases and exposures in a particular assessment.
Summaries of Releases and Exposures
Release and exposure estimates for each source/activity are listed separately in the IRER. This
includes any estimate for which two outputs were enabled - each output is listed as a separate release
in the IRER. Be sure to read the Calculating Two Sets of Results from a Single Model topic for additional
information.
28
-------
ChemSTEER User Guide - Updated May 2015
Combined Releases
Releases are listed individually; however, one special feature in the IRER should be noted. Until
the Combining Releases and Combining Exposures functions are completed in a future version of
ChemSTEER, the IRER combines releases to all environmental media together for each operation into a
"Release Total" that appears after the itemized list of operation releases.
Releases are only combined within an operation if all of the release models have been executed
successfully (i.e., all releases have days of release calculated to be greater than zero).
The "Release Total" is calculated by adding together all releases from all sites over all days.
Within a release, ChemSTEER will use the greater value from either the Output 1 or Output 2 result for
the Release Total.
Hint: it is often helpful to describe any coinciding releases to the extent possible within each
itemized release, as shown in the example below. Go to the Estimating Chemical Releases Tab topic to
read more about the Introductory Notes for the Release Summary input text.
Combined Exposures
Exposures are not combined as a default. Each activity's exposure estimate is listed separately in
the IRER.
The IRER Format
A listing of the ChemSTEER fields used to populate the IRER is shown below (items or values
taken from specific fields in ChemSTEER are denoted in italics):
INITIAL REVIEW ENGINEERING REPORT CBI: [General tab, CBI Yes/No]
[General tab, Assessment Type or General tab, Assessment Type, Other or Other New Chem
text][General tab, Fiscal Year]-[General tab, ldentifier][General tab, Consolidated Case text]
[General tab, Status or General tab, Status, Other text] [General tab, Date]
ENGINEER: [General tab, Name (Assessors Column 1)] \ [General tab, Name (Assessors Column
2)]
PV (kg/yr): [Chemicals tab, Total Assessed Production Volume (PV)]
(PV is an integer if >= 1, else in scientific notation with one digit following the decimal point)
{If the Assessment Type = LVE or LVEMOD and the Submission PV is not binding and not 10,000
kg/yr on the Optional Information tab - Special LVE Considerations, ChemSTEER will display the
Submission PV from the Special LVE Considerations and note the assessed PV from the
Chemicals tab}
[Binding PV (if checked on the Optional Information tab - Special LVE Considerations), Import
Only (if the Type of Notice on the Chemical tab is Import, but not Manufacturing), YX (if
Exposure-Based = Yes on the Optional Information tab - Exposure-Based Criteria), NX (if
29
-------
ChemSTEER User Guide - Updated May 2015
Exposure-Based = No on the Optional Information tab - Exposure-Based Criteria and the PV >
100,000 kg/yr, C.O.S (if checked on the Optional Information tab - Special LVE Considerations),
P2REC (if checked on the Optional Information tab - Pollution Prevention Considerations)]
Revision Notes/Assessment Overview: [General tab, Revision Notes/Assessment] {appears only
if General tab, Revision Notes/Assessment Overview field contains text}
SUBMITTER: [General tab, Company Name]
USE: [Chemical tab, General Description of End Use(s)]
OTHER USES: [Optional Information tab, Misc CRSS Info, Other Uses, Occupational Exposure
Rating, and Consumer Use combo box (i.e., drop-down list), Other Uses]
MSDS: [Optional Information tab, MSDS/Label/Exposure Limits combo box, MSDS Requirements
subtab, MSDS Included Yes/No]
Label: [Optional Information tab, MSDS/Label/Exposure Limits combo box, MSDS Requirements
subtab, Label Included Yes/No]
{The following items appear only if the MSDS Included = Yes and/or if the Label Included = Yes
on the Optional Information tab - MSDS/Label/Exposure Limits}
Gen Eqpt: [Optional Information tab, MSDS/Label/Exposure Limits combo box, MSDS
Requirements subtab, General Equipment]
Respirator: [Optional Information tab, MSDS/Label/Exposure Limits combo box, MSDS
Requirements subtab, Respirator]
Health Effects: [Optional Information tab, MSDS/Label/Exposure Limits combo box, MSDS
Requirements subtab, Health Effects]
LVE PPE: [Optional Information tab, MSDS/Label/Exposure Limits combo box, LVE PPE subtab,
LVE PPE] {Only applicable if the Assessment Type on the General tab is LVE or LVEMOD}
TLV/PEL: [Optional Information tab, MSDS/Label/Exposure Limits combo box, Exposure Limits
subtab, Material] [Optional Information tab, MSDS/Label/Exposure Limits combo box, Exposure
Limits subtab, Concentration] [Optional Information tab, MSDS/Label/Exposure Limits combo
box, Exposure Limits subtab, Exposure Limit] [Optional Information tab, MSDS/Label/Exposure
Limits combo box, Exposure Limits subtab, Exposure Limit Type] [Optional Information tab,
MSDS/Label/Exposure Limits combo box, Exposure Limits subtab, Reference] [Optional
Information tab, MSDS/Label/Exposure Limits combo box, Exposure Limits subtab, Type of
Material]
30
-------
ChemSTEER User Guide - Updated May 2015
{Note: the TLV/PEL label appears once only if exposure limit data is available. Exposure limit
data repeats for multiple chemicals.}
CRSS: [Optional Information tab, Misc CRSS Info, Other Uses, Occupational Exposure Rating, and
Consumer Use combo box, CRSS Date]
Chemical Name: [Chemical tab, Chemical Name] {will not appear if Chemical Name is blank, but
text is entered in Chemical Category}
Chemical Category: [Chemical tab, Chemical Category] {will not appear if Chemical Category is
blank}
S-H20: [Chemical tab, Solubility or Dispersible or Reacts] g/L @ [Chemical tab, Solubility
Temperature]
VP: [Chemical tab, Vapor Pressure (VPchem)] torr @ [Chemical tab, Vapor Pressure
Temperature] (scientific notation with one digit following the decimal point)
MW: [Chemical tab, Molecular Weight (MW)] [Chemical tab, %<500 ] %<500 [Chemical tab,
%<1000 ] %<1000
Physical State and Misc CRSS Info:
[Optional Information tab, Physical State and Misc CRSS Info, Other Uses, Occupational Exposure
Rating, and Consumer Use combo box, Phys State and Misc CRSS Info]
Consumer Use: [Optional Information tab, Other Uses, Occupational Exposure Rating, and
Consumer Use combo box, Consumer Use Yes/No]
SAT (concerns): [Optional Information tab, SAT Data combo box, SAT Date]
Related cases and Misc SAT Info: [Optional Information tab, SAT Data combo box, Related
Cases and Misc SAT Info] {only appears when text is entered}
Migration to groundwater: [Optional Information tab, SAT Data combo box, Migration to
Groundwater] [Optional Information tab, SAT Data combo box, Other Migration to Groundwater
Description]
PBT rating: P[Optional Information tab, SAT Data combo box, P Rating] B[Optional Information
tab, SAT Data combo box, B Rating] T[Optional Information tab, SAT Data combo box, T Rating],
[Optional Information tab, SAT Data combo box, PBT Additional Info]
31
-------
ChemSTEER User Guide - Updated May 2015
Health: [Optional Information tab, SAT Data combo box, Health Rating] [{each of the following
when checked Yes: Dermal, Drinking Water, Inhalation, Not Required, Other, Other Description
XB testing required, XB testing text]
Eco: [Optional Information tab, SAT Data combo box, Eco Rating] [{each of the following when
checked Yes: Water, Water text, Air, Landfill, Not Required, Other, Other Description XB testing
required, XB testing text]
OCCUPATIONAL EXPOSURE RATING: [Optional Information tab, Misc CRSS Info, Other Uses,
Occupational Exposure Rating, and Consumer Use combo box, Occupational Exposure Rating]
NOTES & KEY ASSUMPTIONS:
[Optional Information tab, Notes & Key Assumptions combo box]
POLLUTION PREVENTION CONSIDERATIONS:
[Optional Information tab, Pollution Prevention Considerations combo box, Optional P2
Information from the submission]
P2 Rec: [Optional Information tab, Pollution Prevention Considerations combo box, P2REC]
{appears only when the P2REC box is checked}
EXPOSURE-BASED REVIEW: [Optional Information tab, Exposure-Based Criteria combo box,
Exposure Based Yes/No] [Optional Information tab, Exposure-Based Criteria combo box,
Number of criteria met] criteria met {appears only if Exposure-Based = Yes or No (not blank) in
the Optional Information tab - Exposure-Based Criteria}
{The following list appears only if Exposure-Based = Yes in the Optional Information tab -
Exposure-Based Criteria}
1) # of workers exposed: [Optional Information tab, Exposure-Based Criteria combo box,
Number of Workers Exposed] >1000? [Optional Information tab, Exposure-Based Criteria
combo box, Number of Workers Criteria Met Yes/No]
2) >100 workers with >10 mg/day inhalation exposure: [Optional Information tab, Exposure-
Based Criteria combo box, >100 workers with >10 mg/day inhalation exposure Yes/No]
3) (a) >100 workers with 1-10 mg/day inh. exp. & >100 days/yr: [Optional Information tab,
Exposure-Based Criteria combo box, >100 workers with 1-10 mg/day inh. exp. & >100
days/yr Yes/No]
(b) Routine Dermal Cont: >250 workers & >100 days/yr: [Optional Information tab,
Exposure-Based Criteria combo box, Routine Dermal Cont: >250 workers & >100 days/yr
Yes/No]
Basis: [Optional Information tab, Exposure-Based Criteria combo box, Basis]
page break
32
-------
ChemSTEER User Guide - Updated May 2015
INITIAL REVIEW ENGINEERING REPORT CBI: [General tab, CBI Yes/No]
[General tab, Assessment Type or General tab, Assessment Type, Other or Other New Chem
text][General tab, Fiscal Year]-[General tab, ldentifier][General tab, Consolidated Case text]
{Note: This page repeats for each operation}
[Operations tab, Operation Name]
Number of Sites/Location: [Operation Parameters tab, Mass Balance Parameters subtab,
Number of Sites]
[Operation Parameters tab, Site Information subtab, Facility Name] [Operation Parameters tab,
Site Information subtab, City] [Operation Parameters tab, Site Information subtab, State]
[Operation Parameters tab, Site Information subtab, Zip]
Days/yr: [Operation Parameters tab, Mass Balance Parameters subtab, Operating Days per
Year]
Basis: [Operation Parameters tab, Mass Balance Parameters subtab, Basis Box]
Process Description: [Operations tab, Description subtab, Process Description]
ENVIRONMENTAL RELEASES ESTIMATE SUMMARY
[Releases tab, Introductory Notes for the Release Summary text]
{The following repeats for each release source within the operation. Media are ordered within
the operation in the same top left to bottom right order as shown in the Update Release Media
Output Specifications screen (Water through Other):}
[Releases tab, Media of Release Button, Media]:
[Output Characterization]: [Daily Release Rate (scientific notation with one digit following the
decimal point)] kg/site-day over [Days of Release] days/yr from [NS] site(s) or [Annual Release
Rate Site] kg/site-yr from [NS] site(s) or [Annual Release Rate] kg/yr-all sites
[Output Characterization] {this second set of results appears only if two outputs are enabled}:
[Daily Release Rate (scientific notation with one digit following the decimal point)] kg/site-day
over [Days of Release] days/yr from [NS] site(s) or [Annual Site Release Rate Site] kg/site-yr from
[NS] site(s) or [Annual Release Rate] kg/yr-all sites
from: [Releases tab, Source]
to: [Releases tab, Modify Media of Release screen, To (NPDES number if appropriate)]
basis: [Releases tab, View/Update Release Model Information screen]
33
-------
ChemSTEER User Guide - Updated May 2015
RELEASE TOTAL: [Sum of Annual Release Rate for all sources in the operation (scientific notation
with one digit following the decimal point)] kg/yr - all sites
[Releases tab, Additional Notes for the Release Summary text]
OCCUPATIONAL EXPOSURES ESTIMATE SUMMARY
Tot. # of workers exposed via assessed routes: [Exposures tab, Update Operation Total Number
of Workers Exposed button, Operation total number of workers estimated]
Basis: [Exposures tab, Update Operation Total Number of Workers Exposed button, Basis]
Inhalation:
[Exposures tab, Inhalation Model Input Parameters subtab, Introductory Notes for the
Inhalation Summary]
{The following repeats for each inhalation model within the operation (if applicable):}
Exposure to [Exposures tab, Inhalation Model Input Parameters, Chemical State] ([volatile] or
[non-volatile]) {If the chemical is Mist or Aerosol}
{For respirator class selection [Exposure tab, Respirator Class and Monitoring Review subtab]
(logic below), the chemical is assumed to be volatile if AVPprod > AVPlow for product-related
activities or if AVPrm > AVPlow for any other activity}
(Class I) {If the chemical state is Particulate, or if the AVP associated with the activity is non-
volatile and the chemical state is Mist or Aerosol}
(Class II) {If the chemical state is Vapor}
(Class III) {If the AVP associated with the activity is volatile and the chemical state is Mist or
Aerosol}
[Exposures tab, Inhalation Model Input Parameters, Characterization]: [Exposures tab, Activity
Exposure Estimates, Inhalation Potential Dose Rate] mg/day over [Exposures tab, Inhalation
Model Input Parameters, Exposure Days] days/yr
[Exposures tab, Inhalation Model Input Parameters, Characterization]: [Exposures tab, Activity
Exposure Estimates, Inhalation Potential Dose Rate] mg/day over [Exposures tab, Inhalation
Model Input Parameters, Exposure Days] days/yr {this second set of results appears only if two
outputs are enabled}
34
-------
ChemSTEER User Guide - Updated May 2015
Number of workers (all sites) with inhalation exposure: [Exposures tab, Inhalation Model Input
Parameters, NWexp x NS] {maximum NWexp x NS if two outputs are enabled}
{One of the following texts is displayed, based on the appropriate respirator class [Exposure tab,
Respirator Class and Monitoring Review subtab]: "NOTE: The respirator class is ["I. Particulate
(including solid or liquid droplets)"; "II. Gas/vapor (all substances in the gas form)"; or "III.
Combination Gas/Vapor and Particulate (gas and liquid/solid physical forms are both
present)"]."}
basis: [Exposures tab, Exposure Activity]; [Exposures tab, Inhalation Model Input Parameters,
Basis]
INHALATION MONITORING DATA REVIEW [Exposure tab, Respirator Class and Monitoring
Review subtab]
1) Uncertainty (estimate based on model, regulatory limit or data not specific to that industry)
Yes/No
(Yes/No determined based on the Uncertainty checkbox on the View/Update Exposure Model
Information screen of the Exposures tab)
2) (a) Exposure level > 1 mg/day Yes/No
(Yes if Output 2 is > 1 mg/day for two outputs or if a single output is > 1 mg/day, else No)
OR
(b) Hazard Rating for health of 2 or greater? [Optional Information tab, SAT Data combo box,
Health Rating] Yes/No
(Yes if [Optional Information tab, SAT Data combo box, Health Rating] = 2, 2-3, or 3, else No (or
null if Health Rating is null))
Inhalation Monitoring Data Desired? Yes (both criteria met)/No
(Yes if 1) is Yes and 2(a) or 2(b) is Yes, else No (or null if Health Rating is null))
Dermal:
[Exposures tab, Dermal Model Input Parameters subtab, Introductory Notes for the Dermal
Summary]
{The following repeats for each dermal model within the operation:}
Exposure to [Exposures tab, Dermal Model Input Parameters, Chemical State] at [Exposures tab,
Dermal Input Parameters, Weight Fraction x 100] % concentration
35
-------
ChemSTEER User Guide - Updated May 2015
[Exposures tab, Dermal Model Input Parameters, Characterization]: [Exposures tab, Activity
Exposure Estimates, Dermal Exposure Dose Rate] mg/day over [Exposures tab, Dermal Model
Input Parameters, Exposure Days] days/yr
[Exposures tab, Dermal Model Input Parameters, Characterization]: [Exposures tab, Activity
Exposure Estimates, Dermal Exposure Dose Rate] mg/day over [Exposures tab, Dermal Model
Input Parameters, Exposure Days] days/yr {this second set of results appears only if two outputs
are enabled}
Number of workers (all sites) with dermal exposure: [Exposures tab, Dermal Model Input
Parameters, NWexp x NS] {maximum NWexp x NS if two outputs are enabled}
basis: [Exposures tab, Exposure Activity]; [Exposures tab, Dermal Model Input Parameters,
Basis]
The Contact Report summarizes the information obtained from an external contact.
There are two separate formats for the Contact Report, depending upon whether the report
contains confidential business information (CBI) or does not contain CBI.
A listing of the ChemSTEER fields used to populate each of the contact report types is shown
below (information from fields in ChemSTEER are denoted in italics):
CBI Contact Report Format
The following format is used if the CBI field shows Yes (i.e., contact report does contain TSCA
CBI) in the General tab, View/Update Contact Reports window:
CBI: Yes
MEMORANDUM of TSCA CBI TELEPHONE CONVERSATION
CALL BY: [General tab, View/Update Contact Reports window, Called By]
Organization: [General tab, View/Update Contact Reports window, Called By Affiliation]
CALL TO: [General tab, View/Update Contact Reports window, Call To]
Organization: [General tab, View/Update Contact Reports window, Call To Affiliation]
Date:
[General tab, View/Update Contact Reports window, Call Date]
Time:
[General tab, View/Update Contact Reports window, Call Time]
Phone:
[General tab, View/Update Contact Reports window, Phone]
Concerning what TSCA CBI?
36
-------
ChemSTEER User Guide - Updated May 2015
[General tab, Assessment Type or General tab, Assessment Type, Other, or Other New Chem
text] [General tab, Fiscal Year]-[General tab, Identifier] [General tab, Consolidated Case text]
[General tab, View/Update Contact Reports window, Applicable Assessments]
Content
[General tab, View/Update Contact Reports window, Notes]
Contact Report Format (Report does not contain TSCA CBI)
The following format is used if the CBI field shows No (i.e., contact report does not contain TSCA
CBI) in the General tab, View/Update Contact Reports window:
CBI: No
MEMORANDUM of TELEPHONE CONVERSATION (Contains No TSCA CBI)
CALL BY:
Organization:
[General
[General
tab,
tab,
View/Update
View/Update
Contact
Contact
Reports
Reports
window,
window,
Called By]
Called By Affiliation]
CALL TO:
Organization:
[General
[General
tab,
tab,
View/Update
View/Update
Contact
Contact
Reports
Reports
window,
window,
Call To]
Call To Affiliation]
Date:
[General
tab,
View/Update
Contact
Reports
window,
Call Date]
Time:
[General
tab,
View/Update
Contact
Reports
window,
Call Time]
Phone:
[General
tab,
View/Update
Contact
Reports
window,
Phone]
Concerning what?
[General tab, Assessment Type or General tab, Assessment Type, Other or Other New Chem
text] [General tab, Fiscal Year]-[General tab, Identifier] [General tab, Consolidated Case text]
[General tab, View/Update Contact Reports window, Applicable Assessments]
Content
[General tab, View/Update Contact Reports window, Notes]
37
-------
ChemSTEER User Guide - Updated May 2015
Guide to Using ChemSTEER Tabs
The following sections discuss the eight main tabs in ChemSTEER:
1. General Information Tab
2. Chemical Properties Tab
3. Operations Tab
4. Operations Parameters Tab
5. Estimating Chemical Releases Tab
6. Estimating Chemical Exposures Tab
7. Optional Information Tab
8. Reports Tab
General Information Tab
This tab allows you to view and/or enter general information related to the ChemSTEER
assessment, which includes assessment/case identifiers, status, the assessor(s) and other general
information about the assessment. None of these fields is required in completing an assessment.
However, ChemSTEER will not allow the four identifying fields to be identical when saving to a database
containing more than one assessment.
Identifying Fields
ChemSTEER differentiates each assessment in a database containing more than one assessment
by the information in the four Identifying Fields:
• Assessment Type,
• Status,
• Fiscal Year, and
• Identifier.
To prevent storage of apparently duplicate assessments in one database file, ChemSTEER
requires that information in one or more of the Identifying Fields be different for each assessment.
When Save or Save As is used, ChemSTEER compares the Identifying Fields in the current assessment
with the Identifying Fields of assessments already in the database (Save) or in the destination database
(Save As) to ensure that no assessments in a database have identical identifying fields. These key
identifying fields and the assessment date will be displayed when you open a database containing
multiple assessments.
ChemSTEER displays these four identifying fields, along with the dates/times the assessment
was saved, when Viewing an Assessment's Revision History.
38
-------
ChemSTEER User Guide - Updated May 2015
Assessment Type: Type of assessment. (One of the four identifying fields.)
Drop down list (most of these are typically used by EPA for its reviews of new and existing
chemicals):
• C (Correction),
• LOREX (low release and exposure exemption),
• LOREXMOD (low release and exposure exemption modification),
• LVE (low volume exemption),
• LVEMOD (low volume exemption modification),
• PMN (premanufacture notice),
• SNUN (significant new use notification)
• TME (test marketing exemption),
• I (enforcement),
• Other New Chem (text box appears for Other New Chem),
• Existing Chemical,
• OECD-SIDS (Organisation for Economic Co-Operation and Development - Screening
Information Dataset),
• RM1 (preliminary risk management assessment),
• RM2 (detailed risk management assessment (post-RMl), and
• Other (text box appears for Other).
NOTE: To find out more about OPPT's assessments, go to EPA's web site and search on the
assessment type.
Status: Status of the report. (One of the four identifying fields.)
Drop down list (most of these are typically used by EPA for its reviews of new chemicals):
• Contractor Draft,
• CEB Staff Draft,
• Focus Ready Draft,
• Standard Review Draft,
• Post-Focus Draft Revision 1,
• Post-Focus Draft Revision 2,
• Post-Focus Draft Revision 3,
• Post-Focus Draft Revision 4,
• Post-Focus Draft Revision 5, and
• Other (text box appears for Other).
39
-------
ChemSTEER User Guide - Updated May 2015
Fiscal Year: Fiscal year field. (One of the four identifying fields.)
The fiscal year is for entering a two digit numerical code. For example, fiscal year 2004 is from 1
October 2003 through 30 September 2004, thus the fiscal year code for 2004 is '04'.
Assessment Identifier: Identifying number or text for the assessment. (One of the four
identifying fields.)
If the Assessment Type is one of the "new chemicals" types, which include: C, LOREX,
LOREXMOD, LVE, LVEMOD, PMN, SNUN, TME, I, and Other New Chem, then the Assessment Identifier is
limited to a four digit numerical code.
For any other Assessment Type, the Assessment Identifier is a text field.
Remaining Fields on the General Tab
The following is a list of fields and buttons and the descriptions of each:
Consolidated Case: Designates whether the assessment contains a group of more than one
chemical. Yes or No checkbox. If Yes, a text box appears.
Date: Date of completion corresponding to the Status. ChemSTEER dates the assessment when
first created.
NOTE: Upon clicking Save or Save As, ChemSTEER first checks to see if the date matches today's
date. If not, a message appears asking you if you wish to change the date. Clicking Yes causes
ChemSTEER to update the date to today's date.
CBI: A check box to indicate if the assessment contains TSCA Confidential Business Information.
An "x" in the box indicates Yes.
Number of Contact Reports: Number of phone logs. ChemSTEER keeps track of the number of
phone logs entered in the assessment. This is displayed in General tab.
Name: Name of the assessor
Affiliation: Affiliation of the assessor
Phone: Phone number of the assessor
Email: Email of the assessor
Company Name: company name
Street Address: company address
City: company city
State: company state
Zip: company zip code
Revision Notes/Assessment Overview: Brief notes about the assessment
Update General Information button: Button to display the Update General Information data
entry screen.
40
-------
ChemSTEER User Guide - Updated May 2015
View/Update Contact Report button: Button to display the View/Update Contact Reports
screen.
If you previously contacted the person and saved the contact report in the assessment, you can
quickly transfer the contact information to the new report by selecting the earlier report and clicking
Add/Copy in the View/Update Contact Reports screen. You may then modify any of the contact
information as appropriate for new contact report.
This information can be printed or saved to a text file of a Contact Report (see Contact Report
Format Details).
Update Revision Notes/Assessment Overview button: Button to display a text box for
assessment notes and/or overview.
Chemical Properties Tab
You can view and/or enter information about the chemical to be assessed using the Chemical
tab in ChemSTEER.
Many of the fields shown are for chemical parameters that are commonly used by EPA in
completing assessments. Chemical identification and use fields are for identification and informational
purposes. These fields include chemical identification information including: chemical name and
category; CAS number; molecular formula; and a description of intended use(s) of the chemical (e.g.,
chemical function and end use application, such as surfactant in industrial laundry detergent).
The fields labeled in RED are required inputs for many of ChemSTEER's calculations of mass
balance, releases and worker exposures. Volume parameters are used extensively in the mass balance
and container parameters calculations and in generating release- and exposure-related estimates.
Volume parameters include import and domestic production volumes (or volumes to be assessed).
Physical/chemical properties are parameters that are also commonly used in several of the
ChemSTEER models (e.g., vapor pressure, molecular weight, density).
The Type of Notice designator is used by EPA in distinguishing between reviews for chemicals
that are manufactured domestically (Manufacturing) and/or imported to the U.S. for further processing
and use (Import).
Click on the Update Chemical Information button at the bottom of the tab to revise fields shown
on the tab.
Click on the View/Update Exposure Limits button to see a readily available List of OSHA PELS and
NIOSH RELs obtained for several chemical substances.
NOTE: Be aware that changing certain parameters on this tab will affect the mass balance
calculations, container-related calculations, and release and exposure model estimates. Be sure to read
about ChemSTEER's Hierarchy of ChemSTEER Operations. Activities, and Models.
41
-------
ChemSTEER User Guide - Updated May 2015
Operations Tab
In ChemSTEER, the term "Operation" refers to a workplace or set of "homogeneous" workplaces
with essentially the same (or similar) processes, equipment, chemical throughputs, procedures, and
worker populations, such that estimates of releases and exposures to the chemical being assessed can
be assumed to be essentially the same for all of the workplaces, if more than one, in the set. If
workplaces differ in some aspects that could result in significantly different estimates of releases and
exposures, you should assess these workplaces as two or more separate operations.
There are typically three types of operations in ChemSTEER: Manufacturing, Processing, and
Use. In ChemSTEER, the term "Manufacturing" is generally intended to represent an operation in which
the chemical being assessed is created or formed in a reaction. The term "Processing" is generally
intended to represent an operation in which the chemical being assessed is not created or formed and
in which the chemical being assessed is not destroyed or transformed in a chemical reaction, or
otherwise becomes essentially unavailable for further release or exposure. Formulation and repackaging
operations would usually be considered to be types of Processing operations. The term "Use" is
generally intended to represent an operation in which the chemical being assessed destroyed or
transformed in a chemical reaction, or otherwise becomes essentially unavailable for further release or
exposure.
You can use the Operations tab to view and/or select operations to assess and to view and/or
enter information about each operation's process description, relationships to other operations, the
physical state(s) of the chemical or the mixture containing the chemical, the release source/exposure
activities, and site-specific location and associated information.
Define/Sele
You should first click the "Add/Update Operations" button at the top of the screen, which you
can use to add or delete operations to be assessed. You may add the same operation more than once.
For example, if you wish to assess two different formulation operations, you can add User-defined
Processing twice, and ChemSTEER will label the second addition as User-defined Processing 2.
NOTE: You must select at least one operation to access the ChemSTEER release and exposure
models.
The Add/Update Operations screen has three tabs with different options for adding operations:
• User-defined Operations
• Generic Scenario Operations
• Import Operation
These three options are discussed in the subsections below.
User-defined Operations
The three available User-defined operations (User-defined Manufacturing, User-defined
Processing, and User-defined Use) are for use when none of the generic scenario operations are
appropriate for assessing a workplace of interest. Industry-specific operations have a predetermined set
of default values to define some key parameters used to estimate mass balances, releases, and
42
-------
ChemSTEER User Guide - Updated May 2015
exposures. Some industry-specific operations have associated industry-specific source/activities and
models, while others preselect standard default source/activities from the available list in ChemSTEER.
User-defined operations rely upon you to provide the source/activities, mass balance, and many other
parameter values.
NOTE: It is not recommended that you attempt to utilize the User-Defined Manufacturing
operation for neither a processing or use scenario, nor that you use the User-Defined Use operation for
either a processing or manufacturing scenario. These user-defined operations were specifically designed
to be used for their associated scenarios and have options specific to each type of operation.
Generic Scenario Operations
There are three industry-specific operations that have previously been hard-coded into
ChemSTEER, which include:
• Automobile Original Equipment Manufacture (OEM) Spray Coating.
• Electroplating Bath Additive Use, and
• Recirculating Water-Cooling Tower Additive Use.
These scenarios were created prior to the September 30, 2013 version of ChemSTEER and have
specific logic and all possible default/non-default values programmed into the scenario. Since the
September 30, 2013 version, ChemSTEER allows EPA to save simple generic scenarios to the list, which
provide templates for assessment and include the most conservative default values from the Generic
Scenarios, such as the Use of Photoresist in Semiconductor Manufacturing. These versions have specific
source/activities added, with default parameters included. Parameters can be modified based on
additional information from the submitter. You should review the Help files included for each scenario
to determine the most appropriate default estimates for your assessment.
The Generic Scenario operations are stored in a scenarios.epa database, for which EPA may
distribute updates in the future (see Replacing the Generic Scenario Database).
Because Generic Scenarios can be updated frequently, basis documents are not included in this
Help File. The help document for each specific scenario can be accessed by selecting the scenario of
interest and clicking on the "Generic Scenario Help" button.
Import Operations
In some cases, you may want to complete an assessment similarly to an assessment you have
previously completed. In this case, you can import one more operations from an older assessment into
your current assessment.
To select an operation, first click the "select database" button and specify the
database/assessment which has the operation(s) you are interested in. Double-click the operation, or
select the operation and click "Add to list" This will import the operation into your current assessment.
ChemSTEER will import the operation, sources/activities, and release and exposure models into
your assessment. Note that the relationship for this operation will be successive to any previously added
operation, and the PVop for the imported operation will be set equal to the previous operation.
43
-------
ChemSTEER User Guide - Updated May 2015
Note that since the PVop may have changed, you are required to manually update the mass
balance parameters (Operation Parameters Tab -> Mass Balance Parameters Subtab) before running
models.
s
You can rename an operation to more accurately describe the operation. It is recommended
that if you do rename an operation, that you maintain the original label for that operation, perhaps in
parenthesis, after the new name (e.g., "Formulation of Paint Products (User-defined Processing)). The
original label can be helpful in reminding you what type of ChemSTEER operation you chose.
Set the Order of Operations Within
The operation "ordering" is consistent with their listing in the various tabs and screens in
ChemSTEER and reports (i.e., from top to bottom). The default order of operations is the order in which
you originally selected them in building the assessments. The order of operations is completely
independent of the operation relationships. ChemSTEER passes appropriate variables from operation to
operation (e.g., Yprod -> Yrm) based on the order of relationships set within the Operations Tab ->
Relationships Subtab.
When an assessment contains more than one operation, you may change the order of
operations in the Update Operations window by first clicking on the operation to be "moved" in the
"Selected Operations" grid. The click Move Up and/or Move Down, as appropriate, to "move" that
operation up or down within the assessment.
NOTE: Ordering operations on the Operations tab will have no affect on relationships specified
on the Relationships tab. Setting the order on the Operations tab will only affect the order of
operation display (top to bottom) on summary reports and on the Operations, Operation
Parameters, Releases, and Exposures tabs.
If you reorder the operations, the following warning message will appear once you confirm by
clicking OK:
"You have modified the display of operations, you should return to the Relationships tab
to also modify the relationships (if appropriate)."
Example: You may determine, after completing an import only assessment, that manufacturing
may be domestic and should be added to the assessment. You add manufacturing on the
Update Operations tab. By default, ChemSTEER adds manufacturing as the last operation (since
it was selected last). If appropriate, you may select manufacturing and use the Move Up button
to place manufacturing as the first-listed operation. You also need to modify the relationships
on the Relationships tab such that manufacturing has no proceeding operations and then specify
the operations subsequent to manufacturing.
Removing Operations from I:
44
-------
ChemSTEER User Guide - Updated May 2015
To remove an operation from the assessment, select the operation in the "Selected Operations"
grid and click Remove from list. If you remove an operation from the assessment, you will receive the
following message:
"Are you sure you want to remove the [name] operation from the assessment?
If you remove this operation from the assessment, all of the information associated with
this operation will be removed from the assessment and you will need to reset all
relationships in the assessment"
Simply click Yes to confirm the removal.
As stated in the warning, you should go to the Operations Tab -> Relationships Subtab and
reverify the relationships for the operations remaining in the assessment.
Working with the Operation Subtabs
The data and information contained in the subtabs in the lower half of the Operation tab are
relevant to the Operation that is selected. To select an operation, click on the desired operation label in
the list on the upper half of the Operation tab. The selected Operation is then highlighted. To update the
data fields for any of the subtabs (Description, Relationships, Physical States, Source/Activities, and Site
Information), click on the subtab label and then click on the Update button appropriate to the subtab.
An Update window will appear and you can click on the data field and enter the appropriate
information. Clicking the OK button at the bottom of the window will enter the new information into the
assessment.
You must specify relationships (see Operations Tab -> Relationships Subtab) between more than
one operation within an assessment, which enables certain default values and calculations to execute
properly in ChemSTEER.
You must also select at least one Source/Activity that uses the model that you wish to use in
order to access that model. Source/Activities may be viewed as access vehicles to allow you to use
models. Refer to the Release Sources and Exposure Activities topic in this User Guide to determine
which models are the defaults for each source/activity.
Operations hips Subtab
In ChemSTEER, the term "Relationship" refers to how different workplaces are related as
suppliers and customers. A customer's operation receiving the chemical being assessed from a supplier,
whether pure or in a mixture with other chemicals, makes the customer's operation a subsequent
operation to the supplier's operation. As a default, ChemSTEER assumes a simple serial relationship,
with each operation on the list being the subsequent operation to the previous operation - in the order
that they were selected for the assessment in the Update Operations screen of the Operations tab.
You must specify the relationship between multiple operations within an assessment, which
enables certain default values and calculations to execute properly in ChemSTEER. For example, a
manufacturer of a chemical in a solution (i.e., a supplier assessed via the User-defined Manufacturing
operation) provides that solution to a formulator who blends the chemical solution into a new product
(i.e., a customer assessed via the User-defined Processing operation). For this assessment, you should
45
-------
ChemSTEER User Guide - Updated May 2015
designate the User-defined Processing as a subsequent operation to User-defined Manufacturing. Then,
ChemSTEER assumes that the weight fraction of the chemical in solution leaving the User-defined
Manufacturing operation (Yprod) is equivalent to the weight fraction of the chemical in the solution
entering the User-defined Processing (Yrm) as a default.
NOTE: If you modify a previously saved relationship, it is highly recommended that you reverify
the default parameter values in the Operations Parameters Tab.
Important Notes to Remember when Modifying the Default Relationships
An operation cannot be specified as a subsequent operation more than one time. For example,
if you select Operation B as subsequent to Operation A and then select Operation B again as subsequent
to another Operation C, ChemSTEER will designate the last relationship made (i.e., Operation B is
subsequent to Operation C only) and will reassign the Percent ofPV and PVop as discussed below.
To "move" an operation from the first position in the assessment, select that operation and
verify that the box next to "This operation has no preceding operations" is unchecked in the Update
Operation Relationships screen. That operation may then be added to the list of subsequent operations
that follow another.
To "move" an operation to the first position in the assessment, you must first remove the
operation from any list of subsequent operations in the assessment (by clicking each operation and
viewing the list in the Update Operation Relationships screen for each). Next, select that operation (to
be in the first position) and verify that the box next to "This operation has no preceding operations" is
checked in the Update Operation Relationships screen. You may then add operations to the list of
subsequent operations, as appropriate.
The PVop and Percent of PV Parameters
Two important parameters in operation relationships are PVop and Percent of PV. Percent of PV
represents the PERCENT of the total assessed production volume (PV) (entered on the Chemicals tab)
that flows into or from an operation. For example, if a manufacturing operation (User-defined
Manufacturing) produces all of the total assessed PV, then the Percent of PV for User-defined
Manufacturing is 100 (100%). If there are two primary use operations (User-defined Use and User-
defined Use 2) that are subsequent to the User-defined Manufacturing and three quarters is used by the
first use operation and the remainder by the second use operation, then the Percent ofPV for User-
defined Use is 75 (75%) and the Percent ofPV for User-defined Use 2 is 25 (25%).
PVop is the production volume (kg/yr) that is processed within each operation of the
assessment. In other words, each operation contains a unique PVop that is less than or equal to the total
assessed PV, where:
PVop (kg/yr) = (Percent of PV/100) x total assessed PV
You may change the values of Percent ofPV or PVop for each subsequent operation. Typically,
the following limitations would apply:
• The sum of PVops for all subsequent operations is equal to the PVop in the
preceding operation; and
46
-------
ChemSTEER User Guide - Updated May 2015
• The sum of Percent of PVs for all subsequent operations is equal to the Percent of
PV in the preceding operation.
For example, if Operations M and N are subsequent to Operation L, which has a Percent ofPV =
60 (60%) and a PVop of 60,000 kg/yr, then the Percent ofPV for Operations M and N should add to 60
(60%), and their PVops should add to 60,000 kg/yr.
However, ChemSTEER will allow you to enter PVops and Percent of PVs for subsequent
operations that are not equivalent to those of the preceding operation.
For example, in the scenario shown below, the subsequent operations' PVops are less than the
Mfr
75% of PV
Use 1
20% of PV
Use 2
30% of PV
preceding operation's PVop:
To create this relationship, the Mfr, Use 1, and Use 2 operations were added to the assessment
by clicking the Update Operations button on the Operations tab (see Operations Tab). The relationship
shown above is established by designating both Use 1 and Use 2 as subsequent operations to Mfr. To do
this, click on the Relationships subtab. Select Mfr in the upper box of the Operations tab and then click
the Update Relationships button to view the Update Operation Relationships screen.
First, update the PVop for Mfr to be 75% PV (it defaults to 100% PV). You may already see Use 1
in the list of subsequent operations in the lower portion of the screen (if it was added to the assessment
right after Mfr was added). To establish the above relationship, be sure that both Use 1 and Use 2 are
added to the Subsequent Operations list for the selected Mfr operation. Next, update each of the
subsequent operations' PVops or Percent of PVs to be:
PVmfr = 20% PV; and
PVusel = 30% PV
Clicking OK to return to the Relationships subtab. Use 1 will display PVop = 20% PV and Use 2
will display PVop = 30% PV.
In the scenario illustrated below, the subsequent operations' PVops exceed both the preceding
operation's PVop, as well as the total assessed PV entered on the Chemicals tab:
47
-------
ChemSTEER User Guide - Updated May 2015
Mfr
100% of PV
Use 1
100% of PV
Use 2
30% of PV
Initially, the Mfr and Use 1 operations were added to the assessment. Initial defaults for each of
the PVops are:
PVmfr = 100% PV; and
PVusel = 100% PV
When Use 2 is added as a second, subsequent operation to Mfr, it is added with an initial
PVuse2 = 0% PV.
You may then change the PVop for Use2 (PVuse2) to equal 30% PV in the Update Operation
Relationships screen.
Clicking off the PVuse2 cell does not change the PVop or Percent of PV values (i.e., PVusel =
100% PV and PVuse2 = 30% PV).
Clicking OK to return to the Relationships subtab. Use 1 will display PVop = 100% PV and Use 2
will display PVop = 30% PV. Added together, these account for 130% of the total assessed PV.
ChemSTEER will allow the PVops for a set of subsequent operations to exceed the total assessed
PV entered on the Chemical tab. For this reason, you should use caution when entering PVops and
Percent of PVs in relationships to ensure that you do not exceed the assessment's total PV.
Entering PVops or Percent of PVs that are not equal to the preceding operation's PVop or
Percent of PV allows you to model the following:
A subsequent operation that has a PVop that exceeds the preceding operation can account for
an import of a portion of the total assessed PV at a point between the preceding and subsequent
operations; and
A subsequent operation that has a PVop that is less than the preceding operation can illustrate
an export of a portion of the total assessed PV at a point between the preceding and subsequent
operations.
Operations Tab -> Description Subtab
48
-------
ChemSTEER User Guide - Updated May 2015
The Description subtab allows the user to record NAICS Code, related description information,
and process description for the operation. For industry-specific operations, default process descriptions
are normally provided and are available for editing. Process descriptions, including physical form and
concentration at the beginning and end of the operation, are particularly important in determining a
complete set of sources/activities to assess.
Operations 1-ysicalS'. ubtab
The Physical States subtab allows the user to record physical states for the operation. For
industry-specific operations, default physical states may be provided, which are available for editing.
Future versions of ChemSTEER will use the physical state information input in this subtab to
present a shorter list of more likely sources/activities to the user.
Operations :ab
In ChemSTEER, the term Source/Activity refers to sources and activities in an operation that
can/do/will cause environmental releases and/or worker exposures. Most Sources/Activities have one
or more default models that ChemSTEER uses to estimate releases and exposures. Choosing appropriate
Sources/Activities allow you to access the models to make these estimates.
Many industry-specific operations in ChemSTEER have preselected default Sources/Activities
based on the sources and activities that are expected to occur in these operations. The user-defined
operations require that you select the relevant Sources/Activities to assess.
Some Sources/Activities are specific to a particular industry (e.g., the Automotive Refinish Spray
Coating Application source/activity), while other sources/activities are "broadly applicable" across many
workplaces (e.g., the Loading Liquid Product into Drums or the Sampling Solid Raw Material
sources/activities). The broadly applicable sources/activities available in ChemSTEER are only a subset of
all possible sources and activities and cover those that are often overlooked or considered to be non-
routine or insignificant.
When none of the other available Sources/Activities seem to cover a particular source/activity
that you wish to assess, you may wish to choose from the Sources/Activities listed under the
Miscellaneous Sources/Activities category, which allow you the greatest flexibility in using ChemSTEER to
estimate releases and/or exposures (i.e., these miscellaneous Sources/Activities allow you to choose the
most appropriate release/exposure methods and models to use in the calculations.
Each selected Source/Activity activates one or more equations that represent methods and
models that will quantify the release and/or exposure estimate(s). You can read more about the default
methods and models, as well as the most appropriate alternatives, for each of the Sources/Activities
under the Release Sources and Exposure Activities section of the User Guide.
Adding Sources/Activities to an Operation Assessment
When you update the Source/Activity list for an operation, clicking on the Update
Sources/Activities button activates an Update window. At the top of the Update window is a list that
49
-------
ChemSTEER User Guide - Updated May 2015
initially shows the Source/Activity Category names. At the bottom of the Update window is a list of
Sources/Activities that will be included and assessed for the selected operation.
Double-clicking on a particular Source/Activity Category name opens the list of available
Sources/Activities relevant to the Category. You may either select the Source/Activity that you wish to
add to the operation assessment by clicking on it in the upper list and then clicking on the Add To List
button to add the Source/Activity to the list that will be assessed for the selected operation in
ChemSTEER. Alternately, you may double-click on the Source/Activity that you wish to add to the
operation assessment.
Sources/Activities are numbered in the order that they are added to the assessment. Currently,
there is no functionality to the numbering, and these numbers are carried through the Release and
Exposures tabs.
Note: you may include up to 20 sources/activities within each operation of the assessment.
Automated Addition of Container Unloading and Cleaning Sources/Activities
In most cases wherever a container is unloaded, there are also empty container residues that
are disposed or cleaned within the same operation. For this reason, ChemSTEER will automatically add
the corresponding container cleaning source/activity when you add a container unloading
source/activity and vice versa.
A summary of these corresponding container unloading and cleaning sources/activities is
provided below:
50
-------
ChemSTEER User Guide - Updated May 2015
Container Unloading
Sources/Activities
¦
. Container Residue Disposal/Cleaning
Sources/Activities
Raw Material
Unloading Liquid Raw Material from Bottles
Cleaning Liquid Residuals from Bottles Used to
Transport Raw Material
Unloading Liquid Raw Material from Small Containers
Cleaning Liquid Residuals from Small Containers Used
to Transport Raw Material
Unloading Liquid Raw Material from Drums
Cleaning Liquid Residuals from Drums Used to
Transport Raw Material
Unloading Liquid Raw Material from Totes
Cleaning Liquid Residuals from Totes Used to Transport
Raw Material
Unloading Liquid Raw Material from Tank Trucks
Cleaning Liquid Residuals from Tank Trucks Used to
Transport Raw Material
Unloading Liquid Raw Material from Rail Cars
Cleaning Liquid Residuals from Rail Cars Used to
Transport Raw Material
Unloading Liquid Raw Material from Containers
Cleaning Liquid Residuals from Containers Used to
Transport Raw Material
Unloading Solid Raw Material from Transport
Containers
Cleaning Solid/Powder Residuals from Containers Used
to Transport Raw Material
Product
Unloading Liquid Product from Containers
Cleaning Liquid Residuals from Containers Used to
Transport the Product
Unloading Solid Product from Transport Containers
Cleaning Solid/Powder Residuals from Containers Used
to Transport the Product
User-Defined Material
Unloading Liquid from Storage/Transport Containers
(User-defined)
Cleaning Liquid Residuals from Storage/Transport
Vessels (User-defined)
Unloading Solids from Storage/Transport Containers
(User-defined)
Cleaning Solid Residuals from Storage/Transport
Vessels (User-defined)
The automatic addition of these sources/activities will only occur if you do NOT already have the
source/activity added for the operation. If you do not wish to include either the container unloading or
cleaning source/activity, you may delete it from the operation at any time (see below).
Removing Sources/Activities from an Operation Assessment
To remove a Source/Activity from the list of Sources/Activities that will be assessed in
ChemSTEER (the lower list on the Update window), you may select the Source/Activity that you wish to
remove from that list by clicking on it, then click the Remove From List button. A warning window will
ask you to verify that you wish to remove that Source/Activity from the operation assessment. Simply
click Vesto proceed.
Renaming Sources/Activities
You may wish to rename a Source/Activity in order to denote it with a more appropriate or
descriptive label. To rename a Source/Activity in the list of selected Sources/Activities to be assessed in
51
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER (the lower list on the Update window), simply click on the Source/Activity and type the new
name in the field.
Specifying the Type of Source/Activity Assessment
In the list of selected Sources/Activities to be assessed in ChemSTEER (the lower list on the
Update window) there are columns that determine whether ChemSTEER will assess releases and/or
exposures for each of the selected Sources/Activities. A Yes in either the Release or Exposure column of
the list activates the appropriate default model and allows the use of other available models. A No
indicates that ChemSTEER will not assess that Source/Activity for either a release or worker exposures,
as appropriate. Sources/Activities with a No indicator will not appear in the list of operation
Sources/Activities in either the Releases or Exposures tabs, as appropriate. The indicators in these
columns are ChemSTEER defaults that may be changed by clicking on the Yes or No and typing V(to
change to Yes) or N (to change to No).
Default Model Processing (DMP) Status
The DMP status (i.e., the Release DMP and Exposure DMP columns) indicates whether each of
the selected sources/activities have been "processed" by ChemSTEER and have had their default models
selected. Be sure to read more about Hierarchy of ChemSTEER Operations. Activities, and Models, in
particular the Default Model Processing.
When finished with all changes to the list of Sources/Activities to be assessed for the selected
operation, click OK at the bottom of the Update window, and the updated list should appear in the
Sources/Activities subtab window.
NOTE: You must select at least one Source/Activity in an operation to access ChemSTEER
models.
Set the Order of Sources/Activities Within the Operation
The default order of sources/activities is the order in which you originally added them. Ordering
sources/activities will affect the display order on the Releases and Exposures tabs, and ChemSTEER will
run models in the order of their associated sources/activities. The source/activity display order will not
change on summary reports. ChemSTEER may offer the ability to apply a loss fraction to the amount
remaining from a previous source/activity in future versions; however, until then, the order of
sources/activities is strictly aesthetic.
To change the order of a source/activity, set focus in the Order column of the source/activity to
be changed and click Move Up or Move Down. Clicking Move Up or Move Down will change the
source/activity order by 1, and will automatically adjust the order numbers of the other
sources/activities in the operation based on their current order.
Operations »^ • '.fori , otab
The Site Information subtab allows the user to record site-related (location) information for the
operation. You may save the facility name, address, city, state, zip code, and county for one or more
sites that are being assessed in the selected operation.
52
-------
ChemSTEER User Guide - Updated May 2015
Click the Update Site Information button to enter site information. You can also edit and delete
sites from the assessment.
To add a new site, click the Add button and enter the site's information. Click OK to enter the
information into the assessment.
To modify a site's information, click on the desired site in the Facilities box and then click the
Modify button. Make the desired edits and click OK to enter the revisions.
To remove a site from the operation, click on the site to be removed in the Facilities box and
then click the Delete button and confirm the removal.
If the selected operation is performed at the same facility (or facilities) as the preceding
operation, you may wish to copy all of the site information that was entered for the preceding
operation. To do this, click the Copy Previous Operation button. You may then add, modify or delete the
facility information as appropriate for the selected operation.
Operations Parameters Tab
You can use the Operation Parameters tab to view and/or update key mass balance and
container-related parameters for each of the assessed operations. These key parameters may be used in
generating default values for parameters used in models for release and exposure estimation. The
Operation Parameters tab also contains the Shared Parameters/Factors subtab, where you can input
and specify certain parameters that are shared by more than one release and/or exposure model.
The data fields in the views accessed by clicking on the subtabs in the lower half of the
Operation Parameters tab are relevant to the Operation that is selected. The selected Operation is
highlighted, and you can select another Operation by clicking on that Operation label in the list on the
upper half of the Operation tab. To update the data fields in the subtabs (Mass Balance, Container
Parameters, or Shared Parameters/Factors), click on the subtab label and then click on the Update
button located in each subtab. An Update window will appear and you can click on the data field to
enter the appropriate information. Clicking the OK button at the bottom of the window will enter the
new information into the assessment.
For EACH operation, enter the Mass Balance subtab parameters in the Update window accessed
using the Update Parameters button. Then click on the Container Parameters subtab. The general rules,
calculations, and logic by which ChemSTEER makes mass balance-related parameter estimations are
contained in the Operation Parameters Tab -> Mass Balance Parameters Subtab pages of this User
Guide.
For EACH operation, view the Container Parameter subtab parameters for each of the subtabs
as they are ordered from left to right (For Raw Materials, For Other Materials, For Product, and
Container Parameters by Activity). If you wish to change any of the parameters' values, double-click on
the appropriate Source/Activity name and make the change in the Update window accessed. For each
operation, the term "Raw Material" refers to material entering the operation, whether pure chemical or
chemical in a mixture, and the term "Product" refers to material leaving the operation, whether pure
chemical or chemical in a mixture. The general rules, calculations, and logic by which ChemSTEER makes
53
-------
ChemSTEER User Guide - Updated May 2015
container-related parameter estimations are contained in the Container Parameters Guidance pages of
this User Guide.
When you have completed entering Container Parameters, click on the Shared
Parameters/Factors subtab. For EACH operation, verify any necessary shared parameter values.
Currently, this subtab contains the following types of shared parameters:
• Vapor Pressure Shared Parameters (e.g., Xrm, Xprod, Xother, AVPrm, AVPprod); and
• Automobile Spray Painting Shared Parameters (e.g., designation of the spray gun type,
spray booth type, and mist control technology used in the operation).
Be sure to read the Operation Parameters Tab -> Shared Parameters/Factors Subtab topic.
.. • > 5 ¦ • ! ;e Parameters Subtab
You can use the Mass Balance Parameters subtab to view and/or update key mass balance
parameters for each of the assessed operations. These key mass balance parameters are used
frequently in generating default values for parameters used in models for release and exposure
estimation.
Since batch operations have parameters expressed 'per batch' while most release and exposure
estimates are expressed per time, the Mass Balance subtab allows ChemSTEER to convert batch
variables into time frames.
General Mass Balance Rules and Notes
Rules below apply only if you perform mass balance calculations; however, you may run models
without performing mass balance calculations. Default settings are described in the Mass Balance Basis
Selection.
ChemSTEER currently rounds values that are required to be an integer to the nearest integer
value (with the exception that values less than one are always be rounded to one). In future versions,
ChemSTEER may include recommendations for mitigating rounding errors.
Some user inputs can result in discrepancies in the mass balance logic. Some discrepancies will
result in warnings and/or warning flags; however, ChemSTEER generally allows you to proceed despite
apparent imbalances identified in the mass balance logic.
Some user inputs can result in broad effects on other operations. For example, Yprod is a default
value for subsequent operations. If Yprod for a given operation (e.g., paint formulation) is changed after
a subsequent operation (e.g., paint application) is assessed, the overall mass balance and assessed
exposures and releases of the subsequent operation may contain discrepancies that would require your
correction. ChemSTEER will warn you that changing Yprod can impact appropriateness of parameters'
values in the mass balances and their applications in models in subsequent operations.
If you skip the Mass Balance Parameters tab and proceed directly to an activity/model,
ChemSTEER will assume batch operations as the default. These assumptions will impact the parameters
and associated units displayed on the model input parameters screens.
54
-------
ChemSTEER User Guide - Updated May 2015
Note: ChemSTEER also shows several "placeholder calculate buttons" for several of the mass
balance input parameters. These buttons are currently disabled for all of these input parameters, except
for DMIchem and DMOchem.
Key Mass Accounting Parameters
DMIchem: Daily Mass Input of Chemical (kg/site-day)
DMOchem: Daily Mass Output of Chemical (kg/site-day)
BMIchem: Batch Mass Input of Chemical (kg/site-batch)
BMOchem: Batch Mass Output of Chemical (kg/site-batch)
DMIrm: Daily Mass Input of Raw Material containing the Chemical (kg/site-day)
DMOprod: Daily Mass Output of Product containing the Chemical (kg/site-day)
BMIrm: Batch Mass Input of Raw Material containing the Chemical (kg/site-batch)
BMOprod: Batch Mass Output of Product containing the Chemical (kg/site-batch)
Yrm: Weight Fraction of Chemical in Raw Material (0 < Yrm < 1)
Yprod: Weight Fraction of Chemical in Product (0 < Yprod < 1)
NS: Number of sites (integer > 0)
OD: Operating days per site per year (days/site-yr) (integer > 0 and < 365, OD <
ODmax)
Nby : Number of batches per site per year (batches/site-year) (integer > 0)
Additional Continuous Operation Parameters
HMIchem: Hourly mass input of chemical (kg/site-hr)
HMOchem: Hourly mass output of chemical (kg/site-hr)
HD: Hours per day (0 < HD < 24; default = 24 hours)
Additional Batch-Related Parameters
HB: Hours per batch (hours/batch) (default HB = 24, 0 < HB < 8760)
ODmax: Maximum number of operating days possible for the batch operation
(days/year) (default ODmax = 365, integer > 0 and < 365)
Nbld: Number of batches per line per day (batches/line-day) (Nbld < 24/HB and 0 <
Nbld < Nby)
Ls: Number of processing lines per site (lines/site) (default Ls = 1, integer > 0)
Nbd: Number of batches per site-day (batches/site-day)
These parameters are used to perform mass balance calculations on the three ChemSTEER Mass
Balance Parameters subtabs as described in the sections below:
55
-------
ChemSTEER User Guide - Updated May 2015
• Mass Balance Basis Selection
• Specify Mass Balance Input Parameters
• Specify Other Batch Parameters (hidden if Continuous operation is chosen by the user)
NOTE: Be aware that changing certain parameters on the Mass Balance Parameters Subtab will
affect the container-related calculations and release and exposure model estimates. Be sure to read
about Hierarchy of ChemSTEER Operations. Activities, and Models.
Mass Balance Basis Selection
You will make the following two selections (type of operation and material basis) before
entering values in subsequent mass balance screens:
Choice 1: Select type of Operation
[ ] Continuous Operation
[ ] Batch Operation
The default setting for Choice 1 is Batch Operation for any user-defined operation and for
industry-specific operations, unless otherwise specified.
Choice 2: Use the operation's raw material or product as the basis for mass balance
[ ] Raw Material (raw materials entering the operation)
[ ] Product (product leaving the operation)
The default settings for Choice 2 are as follows:
• Product for User-Defined Manufacturing (Product is not available for User-Defined Use);
and
• Raw Material for User-Defined Processing and User-Defined Use, as well as for industry-
specific operations, unless otherwise specified (Raw Material is not available for User-
Defined Manufacturing).
The default settings described for Choice 1 and Choice 2 are used when you skip the Mass
Balance Parameters tab and proceed directly to a source or activity and its model(s). These assumptions
will impact the parameters and associated units displayed on the model input parameters screens.
The following four combinations describe the possible user decisions and subsequent
calculations made by ChemSTEER based on the selections made on the Mass Balance Basis Selection.
Click on one of the following bases (selected in the Mass Balance Basis Selection subtab) to read
more about the default settings and calculations:
Type of Operation: Continuous; Basis: Raw Material
Type of Operation: Continuous; Basis: Product
56
-------
ChemSTEER User Guide - Updated May 2015
Type of Operation: Batch; Basis: Raw Material
Type of Operation: Batch; Basis: Product
Type of Operation: Continuous: Basis: Raw Material
NOTE: User-defined Manufacturing cannot use Raw Material as a basis.
This screen has four parameter groupings as follows:
First Parameter Grouping (you must specify at least one parameter):
NS: Number of sites
OD: Total number of operating days per year at each site
Second Parameter Grouping (you must specify at least one parameter):
Yrm: Weight fraction of chemical in raw material
DMIrm: Daily mass input of raw material containing the chemical (kg/site-day)
Third Parameter Grouping:
DMIchem: Daily mass input of chemical (kg/site-day)
For user-defined operations, it is recommended that you specify exactly three parameters from
the first three groupings (including at least one parameter from the first grouping and at least one
parameter from the second grouping). You specify parameters by clicking the fix box to the left of the
parameter and entering a positive non-zero value. For industry-specific operations, some of these mass
balance parameters will have default values.
You may elect to enter less than three parameters in the Specify Mass Balance Input Parameters
subtab and ChemSTEER will allow you to move on to subsequent screens.
NOTE: Since many of the mass balance parameters are used as default values and used in
several of the calculations performed in ChemSTEER, not entering/calculating all of the mass
balance parameters may prevent some calculations from being performed in the assessment.
A primary calculation in the Mass Balance Parameter subtabs is DMIchem (daily mass input of
chemical). The following rules describe the ChemSTEER default calculations of DMIchem, based on your
specifications:
If you specify NS and OD, and either Yrm or DMIrm:
DMIchem = PVop / NS/OD
where PVop = the production volume associated with the operation.
If you specify Yrm and DMIrm, and either NS or OD:
57
-------
ChemSTEER User Guide - Updated May 2015
DMIchem =Yrm * DMIrm
You may utilize an hourly input rate for the chemical (HMIchem) and operation hours per day
(HD) to calculate DMIchem.
To execute this calculation, first click the fix box to the left of DMIchem, then click the Calculate
button to the right. Clicking the Calculate button launches the Calculate DMIchem update window,
wherein you enter values for the following input parameters:
HMIchem: Hourly mass input of chemical (kg/site-hr)
HD: Hours per day (0 < HD < 24; default = 24 hours)
After entering these two values, click the Calculate button in the update window to execute the
following equation to calculate DMIchem:
DMIchem = HMIchem (kg/site-hr) x HD (hours/day)
Clicking OK will cause the newly calculated value of DMIchem to overwrite any existing value
that was displayed on the Specify Mass Balance Input Parameters subtab.
If you directly specify DMIchem, DMIchem will be set equal to the value you provide.
Any values entered for HMIchem and HD will be retained on the Calculate DMIchem update
window.
NOTE: For operations THAT HAVE A PRECEDING OPERATION, the default values for Yrm (current
operation) = Yprod FROM THE PRECEDING OPERATION.
If a mass accounting discrepancy is calculated by ChemSTEER based on the following equations,
you will be warned with a pop-up message but allowed to continue. In addition, a warning note will
appear at the bottom of the Specify Mass Balance Input Parameters subtab.
Parameter Percent Error Value Calculation
NS %error = (NSrounded / NScalc -1) * 100
OD %error = (ODrounded / ODcalc -1) * 100
Fourth Parameter Grouping:
Yprod: Weight fraction of chemical in product
DMOprod: Daily mass output of product containing the chemical (kg/site-day)
DMOchem: Daily mass output of chemical (kg/site-day)
For processing operations, the default values for the fourth grouping are as follows:
Yprod (current operation) = Yrm (current operation)
58
-------
ChemSTEER User Guide - Updated May 2015
DMOprod (current operation) = DMIrm (current operation)
DMOchem (current operation) = DMIchem (current operation)
For use operations, the default values for the fourth grouping are as follows:
Yprod (current operation) = 0
DMOprod (current operation) = 0
DMOchem (current operation) = 0
NOTE: No defaults are available for manufacturing operations since User-defined Manufacturing
cannot use Raw Material as a basis.
You may then change up to two of the parameters in the fourth grouping. For industry-specific
operations, some of these mass balance parameters will have default values.
After making these changes, ChemSTEER will recalculate the value of the parameter for which
you click the Recalc button using the following relationship:
DMOprod = DMOchem / Yprod.
The Recalc button is located to the right of the text box for each parameter in the fourth
grouping. If you change one or more parameters in the fourth grouping, you will not be allowed to exit
the screen without clicking the Recalc button for at least one parameter or clicking Cancel to discard ALL
changes (including those made to parameters in the first three groupings).
If you change values in the fourth grouping, the values in the first three groupings are not
affected (i.e., if DMOchem ...DMIchem in a processing operation, ChemSTEER will not make changes to
resolve the apparent discrepancy). ChemSTEER will warn you if this apparent discrepancy occurs.
Type of Operation: Continuous; Basis: Product
NOTE: User-defined Use cannot use Product as a basis.
This screen has four parameter groupings as follows:
First Parameter Grouping (you must specify at least one parameter):
NS: Number of sites
OD: Total number of operating days per year at each site
Second Parameter Grouping (you must specify at least one parameter):
Yprod: Weight fraction of chemical in product
DMOprod: Daily mass output of product containing the chemical (kg/site-day)
Third Parameter Grouping:
59
-------
ChemSTEER User Guide - Updated May 2015
DMOchem: Daily mass output of chemical (kg/site-day)
For user-defined operations, it is recommended that you specify exactly three parameters from
the first three groupings (including at least one parameter from the first grouping and at least one
parameter from the second grouping). You specify parameters by clicking the fix box to the left of the
parameter and entering a positive non-zero value. For industry-specific operations, some of these mass
balance parameters will have default values.
You may elect to enter less than three parameters in the Specify Mass Balance Input Parameters
subtab and ChemSTEER will allow you to move on to subsequent screens.
NOTE: Since many of the mass balance parameters are used as default values and used in
several of the calculations performed in ChemSTEER, not entering/calculating all of the mass
balance parameters may prevent some calculations from being performed in the assessment.
A primary calculation in the Mass Balance Parameter subtabs is DMOchem (daily mass output of
chemical). The following rules describe the ChemSTEER default calculations of DMOchem, based on user
specifications:
If you specify NS and OD, and either Yprod or DMOprod:
DMOchem = PVop / NS / OD
where PVop = the production volume associated with the operation.
If you specify Yprod and DMOprod, and either NS or OD:
DMOchem = Yprod * DMOprod
You may utilize an hourly output rate for the chemical (HMOchem) and operation hours per day
(HD) to calculate DMOchem.
To execute this calculation, first click the fix box to the left of DMOchem, then click the Calculate
button to the right. Clicking the Calculate button launches the Calculate DMOchem update window,
wherein you enter values for the following input parameters:
HMOchem: Hourly mass output of chemical (kg/site-hr)
HD: Hours per day (0 < HD < 24; default = 24 hours)
After entering these two values, click the Calculate button in the update window to execute the
following equation to calculate DMOchem:
DMOchem = HMOchem (kg/site-hr) x HD (hours/day)
Clicking OK will cause the newly calculated value of DMOchem to overwrite any existing value
that was displayed on the Specify Mass Balance Input Parameters subtab.
60
-------
ChemSTEER User Guide - Updated May 2015
If you directly specify DMOchem, DMOchem will be set equal to the value you provided.
Any values entered for HMOchem and HD will be retained on the Calculate DMOchem update
window.
If a mass accounting discrepancy is calculated by ChemSTEER based on the following equations,
you will be warned with a pop-up message but allowed to continue. In addition, a warning note will
appear at the bottom of the Specify Mass Balance Input Parameters subtab.
Parameter Percent Error Value Calculation
NS %error = (NSrounded / NScalc -1) * 100
OD %error = (ODrounded / ODcalc -1) * 100
Fourth Parameter Grouping:
Yrm: Weight fraction of chemical in raw material
DMIrm: Daily mass output of raw material containing the chemical (kg/site-day)
DMIchem: Daily mass input of chemical (kg/site-day)
For processing operations, THAT HAVE NO PRECEDING OPERATION, the default values for the
fourth grouping are as follows:
Yrm (current operation) = Yprod (current operation)
DMIrm (current operation) = DMOprod (current operation)
DMIchem (current operation) = DMOchem (current operation)
For processing operations, THAT HAVE A PRECEDING OPERATION, the default values for the
fourth grouping are as follows:
Yrm (current operation) = Yprod FROM THE PRECEDING OPERATION
DMIchem (current operation) = DMOchem (current operation)
For manufacturing operations, the default values for the fourth grouping are as follows:
Yprod (current operation) = 0
DMOprod (current operation) = 0
DMOchem (current operation) = 0
NOTE: No defaults are available for use operations since User-defined Use cannot use Product as
a basis.
61
-------
ChemSTEER User Guide - Updated May 2015
You may then change up to two of the parameters in the fourth grouping. For industry-specific
operations, some of these mass balance parameters will have default values.
After making these changes, ChemSTEER will recalculate the value of the parameter for which
you click the Recalc button using the following relationship:
DMrm = DMIchem / Yrm.
The Recalc button is located to the right of the text box for each parameter in the fourth
grouping. If you change one or more parameters in the fourth grouping, you will not be allowed to exit
the screen without clicking the Recalc button for at least one parameter or clicking Cancel to discard ALL
changes (including those made to parameters in the first three groupings).
If you change values in the fourth grouping, the values in the first three groupings are not
affected (i.e., if DMIchem ...DMOchem in a processing operation, ChemSTEER will not make changes to
resolve the apparent discrepancy). ChemSTEER will warn you if this apparent discrepancy occurs.
Type of Operation: Batch; Basis: Raw Material
NOTE: User-defined Manufacturing cannot use Raw Material as a basis.
This screen has four parameter groupings as follows:
First Parameter Grouping (you must specify at least one parameter):
NS: Number of sites
Nby: Total number of batches per year at each site
Second Parameter Grouping (you must specify at least one parameter):
Yrm: Weight fraction of chemical in raw material
BMIrm: Batch mass input of raw material containing the chemical (kg/batch)
Third Parameter Grouping:
BMIchem: Batch mass input of chemical (kg/batch)
For user-defined operations, it is recommended that you specify exactly three parameters from
the first three groupings (including at least one parameter from the first grouping and at least one
parameter from the second grouping). You specify parameters by clicking the fix box to the left of the
parameter and entering a positive non-zero value. For industry-specific operations, some of these mass
balance parameters will have default values.
You may elect to enter less than three parameters in the Specify Mass Balance Input Parameters
subtab and ChemSTEER will allow you to move on to subsequent screens.
62
-------
ChemSTEER User Guide - Updated May 2015
NOTE: Since many of the mass balance parameters are used as default values and used in
several of the calculations performed in ChemSTEER, not entering/calculating all of the mass
balance parameters may prevent some calculations from being performed in the assessment.
A primary calculation in the Mass Balance Parameter subtabs is BMIchem (batch mass input of
chemical). The following rules describe the ChemSTEER default calculations of BMIchem, based on user
specifications:
If you specify NS and Nby, and either Yrm or BMIrm:
BMIchem = PVop / NS/ Nby
where PVop = the production volume associated with the operation.
If you specify Yrm and BMIrm, and either NS or Nby:
BMIchem =Yrm * BMIrm
If you specify BMIchem, BMIchem will be set equal to the value you provide.
NOTE: For operations THAT HAVE A PRECEDING OPERATION, the default values for Yrm (current
operation) = Yprod FROM THE PRECEDING OPERATION.
If a mass accounting discrepancy is calculated by ChemSTEER based on the following equations,
you will be warned with a pop-up message but allowed to continue. In addition, a warning note will
appear at the bottom of the Specify Mass Balance Input Parameters subtab.
Parameter Percent Error Value Calculation
NS %error = (NSrounded / NScalc -1) * 100
Nby %error = (Nbyrounded / Nbycalc -1) * 100
Fourth Parameter Grouping:
Yprod: Weight fraction of chemical in product
BMOprod: Batch mass output of product containing the chemical (kg/site-day)
BMOchem: Batch mass output of chemical (kg/site-day)
For processing operations, the default values for the fourth grouping are as follows:
Yprod (current operation) = Yrm (current operation)
BMOprod (current operation) = BMIrm (current operation)
BMOchem (current operation) = BMIchem (current operation)
For use operations, the default values for the fourth grouping are as follows:
63
-------
ChemSTEER User Guide - Updated May 2015
Yprod (current operation) = 0
BMOprod (current operation) = 0
BMOchem (current operation) = 0
NOTE: No defaults are available for manufacturing operations since User-defined Manufacturing
cannot use Raw Material as a basis.
You may then change up to two of the parameters in the fourth grouping. For industry-specific
operations, some of these mass balance parameters will have default values.
After making these changes, ChemSTEER will recalculate the value of the parameter for which
you click the Recalc button using the following relationship:
BMOprod = BMOchem / Yprod.
The Recalc button is located to the right of the text box for each parameter in the fourth
grouping. If you change one or more parameters in the fourth grouping, you will not be allowed to exit
the screen without clicking the Recalc button for at least one parameter or clicking Cancel to discard ALL
changes (including those made to parameters in the first three groupings).
If you change values in the fourth grouping, the values in the first three groupings are not
affected (i.e., if BMOchem ...
BMIchem in a processing operation, ChemSTEER will not make changes to resolve the apparent
discrepancy). ChemSTEER will warn you if this apparent discrepancy occurs.
Continue to Specify Other Batch Parameters subtab
Type of Operation: Batch; Basis: Product
NOTE: User-defined Use cannot use Product as a basis.
This screen has four parameter groupings as follows:
First Parameter Grouping (you must specify at least one parameter):
NS: Number of sites
Nby: Total number of batches per year at each site
Second Parameter Grouping (you must specify at least one parameter):
Yprod: Weight fraction of chemical in product
BMOprod: Batch mass output of product containing the chemical (kg/batch)
Third Parameter Grouping:
BMOchem: Batch mass output of chemical (kg/batch)
64
-------
ChemSTEER User Guide - Updated May 2015
For user-defined operations, it is recommended that you specify exactly three parameters from
the first three groupings (including at least one parameter from the first grouping and at least one
parameter from the second grouping). You specify parameters by clicking the fix box to the left of the
parameter and entering a positive non-zero value. For industry-specific operations, some of these mass
balance parameters will have default values.
You may elect to enter less than three parameters in the Specify Mass Balance Input Parameters
subtab and ChemSTEER will allow you to move on to subsequent screens.
NOTE: Since many of the mass balance parameters are used as default values and used in
several of the calculations performed in ChemSTEER, not entering/calculating all of the mass
balance parameters may prevent some calculations from being performed in the assessment.
A primary calculation in the Mass Balance Parameter subtabs is BMOchem (batch mass output
of chemical). The following rules describe the ChemSTEER default calculations of BMIchem, based on
your specifications:
If you specify NS and Nby, and either Yprod or BMOprod:
BMOchem = PVop / NS / Nby
where PVop = the production volume associated with the operation.
If you specify Yprod and BMOprod, and either NS or Nby:
BMOchem = Yprod * BMOprod
If you specify BMOchem, BMOchem will be set equal to the value you provide.
If a mass accounting discrepancy is calculated by ChemSTEER based on the following equations,
you will be warned with a pop-up message but allowed to continue. In addition, a warning note will
appear at the bottom of the Specify Mass Balance Input Parameters subtab.
Parameter Percent Error Value Calculation
NS %error = (NSrounded / NScalc -1) * 100
Nby %error = (Nbyrounded / Nbycalc -1) * 100
Fourth Parameter Grouping:
Yrm: Weight fraction of chemical in raw material
BMIrm: Batch mass input of raw material containing the chemical (kg/site-day)
BMIchem: Batch mass input of chemical (kg/site-day)
For processing operations THAT HAVE NO PRECEDING OPERATION, the default values for the
fourth grouping are as follows:
65
-------
ChemSTEER User Guide - Updated May 2015
Yrm (current operation) = Yprod (current operation)
BMIrm (current operation) = BMOprod (current operation)
BMIchem (current operation) = BMOchem (current operation)
For processing operations THAT HAVE A PRECEDING OPERATION, the default values for the
fourth grouping are as follows:
Yrm (current operation) = Yprod FROM THE PRECEDING OPERATION
BMIchem (current operation) = BMOchem (current operation)
For manufacturing operations, the default values for the fourth grouping are as follows:
Yrm (current operation) = 0
BMIrm (current operation) = 0
BMIchem (current operation) = 0
NOTE: No defaults are available for use operations since User-defined Use cannot use Product as
a basis.
You may then change up to two of the parameters in the fourth grouping. For industry-specific
operations, some of these mass balance parameters will have default values.
After making these changes, ChemSTEER will recalculate the value of the parameter for which
you click the Recalc button using the following relationship:
BMrm = BMIchem / Yrm.
The Recalc button is located to the right of the text box for each parameter in the fourth
grouping. If you change one or more parameters in the fourth grouping, you will not be allowed to exit
the screen without clicking the Recalc button for at least one parameter or clicking Cancel to discard ALL
changes (including those made to parameters in the first three groupings).
If you change values in the fourth grouping, the values in the first three groupings are not
affected (i.e., if BMIchem ...
BMOchem in a processing operation, ChemSTEER will not make changes to resolve the apparent
discrepancy). ChemSTEER will warn you if this apparent discrepancy occurs.
Continue to Specify Other Batch Parameters subtab
This screen is used for Batch operations only. You cannot access this tab until a value for at least
the Nby parameter (number of batches per site, per year) has been entered or calculated in the Specify
66
-------
ChemSTEER User Guide - Updated May 2015
Mass Balance Input Parameters subtab for Batch operations. This screen has three parameter groupings
as follows:
First Parameter Grouping:
Nby: Number of batches/site-year (carried forward from Specify Mass Input
Balance Parameters subtab, read-only - cannot be specified or changed
on this screen).
HB: Hours per batch
ODmax: Maximum possible operating days
Nby is the same value specified or calculated from the Specify Mass Balance Input Parameters
subtab.
You should specify HB and change ODmax, if appropriate.
Second Parameter Grouping: (parameters calculated based on the logic below)
Nbld: Number of batches per line per day
Ls: Processing lines per site
OD: Operating days per year
The second parameter groupings are calculated based on defaults or recalculated if you change
a first parameter grouping and click off of the parameter.
Third Parameter Grouping
Nbd: Number of batches/site-day (read-only - cannot be specified or
changed) = Nbld * Ls
You specify parameters by entering a positive non-zero value and clicking the checkbox for the
parameter. Based upon your specifications from the first parameter grouping, ChemSTEER calculates
default values for the second and third parameter groupings as follows:
If HB # 24 AND Nby <= ODmax, then ChemSTEER defaults to the following:
Ls = 1
Nbld = 1
OD = Nby
If HB >24 and/or Nby >365 AND (HB*Nby)/24 <= ODmax, then ChemSTEER defaults are the
following:
Ls =1
OD = (HB*Nby / Ls) / 24
Nbld = Nby / OD / Ls
If HB >24 and/or Nby >365 and/or (HB*Nby)/24 > ODmax, then ChemSTEER defaults to the
following:
67
-------
ChemSTEER User Guide - Updated May 2015
Increase Ls by one until (HB*Nby / Ls) / 24 is less than or equal to ODmax
OD = (HB*Nby / Ls) / 24
Nbld = Nby/OD/ Ls
You may then change up to two of the parameters in the second parameter grouping. After
making these changes, ChemSTEER will recalculate the value of the parameter for which you click the
Re-Calculate button using the following relationship:
OD = Nby / Nbld / Ls.
If a mass accounting discrepancy is calculated by ChemSTEER based on the parameters the
following equations, you will be warned with a pop-up message but allowed to continue. In addition, a
warning note will appear at the bottom of this mass balance screen.
Parameter Percent Error Value Calculation
Ls % error = (Lsrounded / Lscalc -1) * 100
OD % error = (ODrounded / ODcalc -1) * 100
The Re-Calculate button is next to the text box for each parameter in the second grouping. If
you change one or more parameters in the second grouping, you will not be allowed to exit the screen
without pressing the Re-Calculate button for at least one parameter or pressing the Cancel button to
discard ALL changes (including those made to parameters in the first grouping).
Operation Parameters Tab Container Parameters Sub tab
You can use the Container Parameter subtab to view and/or update key container-related
parameters for each of the assessed operations. These key container parameters are used frequently in
generating default values for parameters used in models for release and exposure estimation.
For EACH operation, view the Container Parameter subtab parameters for each of the subtabs
as they are ordered from left to right (For Raw Materials, For Other Materials, For Product, and
Container Parameters by Activity). If you wish to change any of the parameters' values, double-click on
the appropriate Source/Activity name and make the change in the Update window accessed.
The general rules, calculations, and logic by which ChemSTEER makes container parameter-
related estimations are contained in the Container Parameters Guidance page of this User Guide.
Container Parameters Guidance
The logic and parameters are described below for the ChemSTEER Container Parameters subtab
when the user clicks the Update Parameters button.
This tab is used to verify and/or specify container-related parameters that are sometimes
relevant to both release models and exposure models.
General Container Parameter Rules and Notes
68
-------
ChemSTEER User Guide - Updated May 2015
Rules below apply only if user performs container parameter calculations; however, the user
may run models without performing container parameter calculations. ChemSTEER will generate some
default values without any user action under the Container Parameter subtabs.
ChemSTEER currently rounds values that are required to be an integer to the nearest integer
value (with the exception that values less than one are always be rounded to one). In future versions,
ChemSTEER may include "recommendations" for mitigating rounding errors.
Some user inputs can result in discrepancies in the mass balance and/or container logic. Some
discrepancies will result in warnings and/or warning flags. However, ChemSTEER generally allows the
user to proceed despite apparent imbalances identified in the mass balance logic.
Some user inputs can result in broad effects on other operations. For example, Yprod is a default
value for subsequent operations. If Yprod for a given operation (e.g., paint formulation) is changed after
a subsequent operation (e.g., paint application) is assessed, the overall mass balance, container
parameters, and assessed exposures and releases of the subsequent operation may contain
discrepancies that would require user correction. ChemSTEER will warn the user that changing Yprod
can impact appropriateness of parameters' values in the mass balances and their applications in
container logic and models in subsequent operations.
Key Container Parameters
fc: Fraction of total volume (raw material or product) shipped in this container,
dimensionless (0 < fc < 1)
Vc: Container volume (gal)
i: Activity designator (can be used for any activities using raw material (rm), product
(prod), or other user-defined material)
Di: Density of material handled in activity i (kg/L) (default Di = 1, except Drm (current
operation) = Dprod from the preceding operation)
Yi: Weight fraction of chemical in material handled in activity i, dimensionless (0 < Yi < 1)
MCi: Mass of material in container handled in activity i (kg/container)
OD: Days per site per year for the operation (days/year) (read-only from Mass Balance)
Ncy: Number of containers per site per year (containers/site-year)
ODa: Days per site per year for the activity (days/yr) (integer > 0 and < 365)
Ned: Number of containers per site per day (containers/site-day) (Ned < Ncy)
r: Rate of unloading/loading containers (containers/hour)
OHa: Hours per day for the activity (hours/day) (0 < OHa < 24)
These parameters are used to perform container-handling calculations on the ChemSTEER
Container Parameters subtabs, as described in the links below:
• Verify/Select Container Parameters
69
-------
ChemSTEER User Guide - Updated May 2015
• Verify/Select Container Parameter by Activity
NOTE: Be aware that changing certain parameters on the Container Parameters subtab will
affect the release and exposure model estimates. Be sure to read about Hierarchy of ChemSTEER
Operations. Activities, and Models.
V'erify/Select Container Parameters
The following three subtabs are displayed on the Container Parameters subtab:
• For Raw Material
• For Product, and
• For Other Material.
Tables in these three tabs are populated based on container-related activities and other
activities that are potentially container-related (e.g., miscellaneous sources and activities) selected for
the operation. ChemSTEER places the activity in the "most logical" tab for the purpose of determining
initial sets of default values and calculations. This placement is shown in the table below. The
appearance of an activity being in an inappropriate category simply means that you may have to
override the default values to send more appropriate parameter values to models that use those
parameters.
70
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER Placement of Sources and Activities into Container Groupings
Activity Name
Default Subtab for
Container Parameters
Category Name: Cleaning Liquid Residuals from Transport Containers/Vessels
Cleaning Liquid Residuals from Bottles Used to Transport the Raw Material
Raw Material
Cleaning Liquid Residuals from Small Containers Used to Transport the Raw Material
Raw Material
Cleaning Liquid Residuals from Drums Used to Transport the Raw Material
Raw Material
Cleaning Liquid Residuals from Totes Used to Transport the Raw Material
Raw Material
Cleaning Liquid Residuals from Tank Trucks Used to Transport the Raw Material
Raw Material
Cleaning Liquid Residuals from Rail Cars Used to Transport the Raw Material
Raw Material
Cleaning Liquid Residuals from Containers Used to Transport the Raw Material
Raw Material
Cleaning Liquid Residuals from Bottles Used to Transport the Raw Material
Product
Cleaning Liquid Residuals from Small Containers Used to Transport the Raw Material
Product
Cleaning Liquid Residuals from Drums Used to Transport the Raw Material
Product
Cleaning Liquid Residuals from Totes Used to Transport the Raw Material
Product
Cleaning Liquid Residuals from Tank Trucks Used to Transport the Raw Material
Product
Cleaning Liquid Residuals from Rail Cars Used to Transport the Raw Material
Product
Cleaning Liquid Residuals from Containers Used to Transport the Raw Material
Product
Cleaning Liquid Residuals from Storage/Transport Vessels (User-Defined)
Other Material
Category Name: Cleaning Solid Residuals from Transport Containers/Vessels
Cleaning Solid/Powder Residuals from Containers Used to Transport the Raw Material
Raw Material
Cleaning Solid/Powder Residuals from Containers Used to Transport the Product
Product
Cleaning Solid Residuals from Storage/Transport Vessels (User-Defined)
Other Material
Category Name: Loading Liquids into Transport Containers/Vessels
Loading Liquid Product into Bottles
Product
Loading Liquid Product into Small Containers
Product
Loading Liquid Product into Drums
Product
Loading Liquid Product into Totes
Product
Loading Liquid Product into Tank Trucks
Product
Loading Liquid Product into Rail Cars
Product
Loading Liquid Product into Containers
Product
Loading Liquid Raw Materials into Containers
Raw Material
Loading Liquid into Storage/Transport Vessels (User-Defined)
Other Material
Category Name: Loading Solids into Transport Containers/Vessels
Loading Solid Product into Transport Containers
Product
Loading Solid Raw Material into Transport Containers
Raw Material
Loading Solids into Storage/Transport Vessels (User-Defined)
Other Material
Category Name: Unloading Liquids into Transport Containers/Vessels
Unloading Liquid Raw Material from Bottles
Raw Material
Unloading Liquid Raw Material from Small Containers
Raw Material
Unloading Liquid Raw Material from Drums
Raw Material
71
-------
ChemSTEER User Guide - Updated May 2015
Unloading Liquid Raw Material from Totes
Raw Material
Unloading Liquid Raw Material from Tank Trucks
Raw Material
Unloading Liquid Raw Material from Rail Cars
Raw Material
Unloading Liquid Raw Material from Containers
Raw Material
Unloading Liquid Product from Containers
Product
Unloading Liquid from Storage/Transport Containers (User-Defined)
Other Material
Category Name: Unloading Solids into Transport Containers/Vessels
Unloading Solid Raw Materials from Transport Containers
Raw Material
Unloading Solid Product from Transport Containers
Product
Unloading Solids from Storage/Transport Containers (User-Defined)
Other Material
These three tabs allow you to view and change several operation-related parameters for each
activity, including:
• Fractions of annual operation volume relevant to the activity,
• Volumes of storage and transport containers,
• Densities for the material(s),
• Mass of material in a container, and
• Weight fraction(s) of the chemical in the material(s).
Activities involving liquids are assigned default values by ChemSTEER. You may update values of
parameters on the For Raw Material, For Product, and For Other Material subtabs.
Total fractions of annual operation volumes for each of the raw material and product should
normally sum to 1. If you exceed the sum of 1 for raw materials or product, you will be warned with a
pop-up message but allowed to continue.
ChemSTEER uses initial default value of fc based on the following equation:
fc = l/(number of activities for either raw material, product, or other material, as appropriate)
For all activities, the defaults for Yi are summarized below:
Yi = Yrm for activities handling raw material or other material.
Yi = Yprod for activities handling product.
Liquid-Handling Activity Defaults
For activities involving liquids, default values for Vc and Unloading/Loading Rates (r) are summarized
in the table below:
72
-------
ChemSTEER User Guide - Updated May 2015
Table 1. Default Values for Container Volumes (Vc) and Unloading/Loading Rates (r) for Activities
Involving Liquids
Vessel Name
Default Volume
Range of Volumes
Container
Average
(Vc), [gal]
[gal]
Unload/Load
Unload/Load
Rate (r),
Rate,
[containers/hr]
[gal/min]
Bottles
1
<5
Conservative Case
90
1.5
Typical Case
60
1.0
Small Containers
5
> 5 to < 20
Conservative Case
90
7.5
Typical Case
60
5.1
Drums
55
> 20 to <100
Conservative Case
30
27.5
Typical Case
20
18.3
Totes
550
> 100 to < 1,000
Conservative Case
30
27.5
Typical Case
20
18.3
Tank Truck
5,000
> 1,000 to < 10,000
Conservative Case
2
167
Typical Case
2
167
Rail Car
20,000
> 10,000
Conservative Case
1
333
Typical Case
1
333
Source: portions from USEPA, 1991, Table 4-11.
The defaults for Di are summarized below:
Di = Drm for activities handling raw material or other material
Di = Dprod for activities handling product.
The overall ChemSTEER default value for Di is one kilogram per liter (1 kg/L), except Drm (current
operation) = Dprod from the preceding operation.
ChemSTEER calculates MCi based on the values of Vc and Di using the following equation:
MCi = Vc * Di * 3.785 L/gal
You may delete the values of Vc and Di to enter a new value for MCi directly. Alternatively, you
may change either Vc or Di and ChemSTEER will update the value of MCi based on the equation above.
Solid-Handling Activity Defaults:
For activities involving solids, there are no default values for Vc, Di and MCi. You must either
specify a value for MCi (Vc and Di left blank) or specify values for Vc and Di. ChemSTEER will then
calculate MCi using the following equation:
MCi = Vc * Di * 3.785 L/gal
73
-------
ChemSTEER User Guide - Updated May 2015
Verify/Select Container Parameter by Activity
This tab allows you to view or change the activity-specific parameters listed in the table below.
The default values for each of the parameters are presented in Table 1 above.
Activity-Specific Parameters and Default Values
Activity-Specific
Parameter
Definition
Default Value
Ncy
Number of containers per site per year
(PVop*fc)/(NS*Yi*MCi)
ODa
Days per site per year for the activity
Nby (only if batch operation and Nbd <1),
otherwise OD
Ned
Number of containers per site per day
Ncy/ODa
R
Rate of unloading/loading containers
(containers/hour)
Typical case value from Table 2, based on
container size
OHa
Hours per day for the activity
Ncd.r
This subtab displays three parameter groupings, as follows:
First Parameter Grouping (you may select up to two parameters):
Ncy (number of containers per site-year)
ODa (days per site-year for the container-related activity)
Second Parameter Grouping (you may select up to two parameters total in the Second and
Third Groupings):
Ned (number of containers per site-day)
Third Parameter Grouping (you may select up to two parameters total in the Second and Third
Groupings):
r (load/unload rate, containers per hour)
OHa (hours per site-day for the container-related activity)
You may revise the default values calculated by ChemSTEER. To make revisions, you must select
a total of exactly three parameters that ChemSTEER should use to calculate the remaining two
parameters. You select parameters using one of the following options:
• To retain the default value, click the checkbox for the parameter; or
• To change the default value, enter a positive non-zero value and then click the checkbox
for the parameter.
Based on the selected parameters' values, ChemSTEER will recalculate the values of the
remaining parameters using the following equations:
Ned = Ncy/ODa
OHa = Ncd/r
74
-------
ChemSTEER User Guide - Updated May 2015
If a mass accounting discrepancy is calculated by ChemSTEER based on the following equations,
you will be warned with a pop-up message but allowed to continue. The warning note at the bottom of
the screen will appear on this container parameters screen.
Parameter Error Cause Percent Error Value Calculation
ODa rounding %error = (ODarounded/ODacalc -1) * 100
Ncy user-selected values %error = [Ncy/((PVop * fc)/(NS * Yi * MCi)) -1] * 100
Operation Parameters Tab -> Shared Parameters/Factors Subtab
The logic and parameters are described below for the ChemSTEER Operation Parameters tab,
Shared Parameters/Factors subtab when the user clicks the Update Parameters button.
This tab is used to verify and/or specify parameters and factors that are shared by more than
one release and/or exposure model used within an operation. These are additional parameters that are
not specified in the Chemical tab, Operations subtabs, or the other Operation Parameters subtabs (i.e.,
Mass Balance and Container Parameters).
NOTE: Be aware that changing certain parameters on this subtab will affect the release and
exposure model estimates. Be sure to read about Hierarchy of ChemSTEER Operations. Activities, and
Models.
General Shared Parameters/Factors Rules and Notes
The rules below apply only if the user performs calculations and/or enters values under this
subtab; however, the user may run models without entering/performing calculations under this subtab.
Default values will be generated by ChemSTEER without any user action.
Shared parameters or factors for models specific to a particular industry operation (e.g., spray
gun type for the Automotive OEM and Refinishing Spray Coating operations) will only appear as
preselected by default when the particular operation is selected on the list of assessed operations. Such
parameters are included in the discussion of the logic for the appropriate industry-specific operation (in
the User Guide's ChemSTEER Methods and Models, Industry-Specific Operations topics).
The adjusted vapor pressure range values (AVPlow and AVPhigh) used for activating the vapor
models for the assessment appear in this subtab. Shared parameters for vapor-related models (e.g.,
vapor generation release models and the mass balance inhalation model) will be preselected by default,
based on preselection default conditions outlined below.
Key Shared Parameters
AVPhigh: High end of Adjusted Vapor Pressure Range for the assessment (torr; 0 <
AVPhigh; default AVPhigh = AVPhigh from Preferences/Vapor Model Activation)
AVPlow: Low end of Adjusted Vapor Pressure Range for the assessment (torr; 0 <
AVPlow; default AVPlow = AVPlow from Preferences/Vapor Model Activation)
75
-------
ChemSTEER User Guide - Updated May 2015
AVPrm:
Adjusted Vapor Pressure for Raw Material for the selected operation (torr; 0 <
AVPrm; read-only: AVPrm = Xrm x VP)
AVPprod: Adjusted Vapor Pressure for Product for the selected operation (torr; 0 <
AVPprod; read-only: AVPprod = Xprod x VP)
Xrm:
Vapor Pressure Correction Factor for Raw Material for the selected operation
(dimensionless; 0 < Xrm < 1; default Xrm = Xprod for the PREVIOUS operation
or, if no previous operation, 1)
Xprod:
Vapor Pressure Correction Factor for Product for the selected operation
(dimensionless; 0 < Xprod < 1; default Xprod = Xrm)
Xother:
Vapor Pressure Correction Factor for Other Material for the selected operation
(dimensionless; 0 < Xother < 1; default Xother = Xrm)
The Shared Parameters/Factors subtab will show the following parameters or factors. If a
selected industry-specific operation has default models that share parameters or factors, those
parameters or factors are shown in the Shared Parameters/Factors subtab (e.g., spray gun type for
Automotive spray coating operations). These parameters will be preselected on the Shared
Parameters/Factors subtab based on the operation except for the group of vapor model parameters,
which may be preselected based on the following conditions. Industry operation shared parameters are
described in the applicable industry-specific operation User Guide topic.
Adjusted Vapor Pressure Range Default Values for the Current Assessment
The adjusted vapor pressure range (AVPlow and AVPhigh) for the current assessment is shown
on this subtab. When a new assessment is started, the initial default values for this range are set to the
values for the workstation on which ChemSTEER is being run. These workstation-specific values may be
viewed and changed from the ChemSTEER menu item Preferences/Vapor Model Activation. You can
change the values of this range by clicking on the value you wish to change and typing a new value.
If any AVP for the operation > AVPlow for the assessment, then the entire group of vapor model
parameters (AVPrm, AVPprod, Xrm, Xprod, and Xother) are shown. Be sure to read the Adjusted Vapor
Pressure for the Operation topic.
Model Group Preselection Default Conditions
You can change the availability of shared parameter/factor groups that were preselected by
ChemSTEER by clicking the Update Available Shared Parameters/Factors button and manually selecting
or deselecting model groups for each operation. Parameters or factors in the selected groups are
displayed on the Shared Parameters/Factors subtab and are available for use by any model within that
operation to which the parameter or factor applies. ChemSTEER may have default values (e.g., X=l)
available to the models even if you have deselected the model group. ChemSTEER will retain the
parameter defaults or user changes even after model groups have been deselected; however, you will
need to select model groups to update values.
76
-------
ChemSTEER User Guide - Updated May 2015
When the user clicks on the Update Available Shared Parameters/Factors button on the Shared
Parameters/Factors subtab, an update window will be displayed showing the selected shared
parameter/factor groups and all shared parameter/factor groups that are available for the operation.
The following shared parameters/factors groups are currently implemented in ChemSTEER:
• Vapor Pressure Shared Parameters (see Adjusted Vapor Pressure for the Operation)
• Auto Spray Painting Shared Parameters
The list of shared parameters on the Shared Parameters/Factors subtab will include the model
group and the parameter/factor's name, type, value, and units. Depending on the parameter, the
parameters may be updated by one of following methods after double clicking on the Type label of a
particular parameter:
An update window will be launched to change the Value or Type label for that parameter or
factor, or
You can change the Type label to either Default or User-defined Default. If you change the Type
label to User-defined Default, the Value field for that specific shared parameter will become updateable.
If you switch the shared parameter type back to Default, the value for that shared parameter will be
reset to its default value.
Adjusted Vapor Pressure for the Operation
An adjusted vapor pressure (AVP) for an operation is the product of a vapor pressure correction
factor (X) for the material handled within the operation and the vapor pressure of the assessed chemical
(VPchem). An AVP is used in determining whether vapor-related release and exposure models are
appropriate default models for some liquid-related sources/ activities in an operation. For each
operation, there are two AVP options: AVPrm and AVPprod.
The default adjusted vapor pressure (AVP) for each liquid-related source/ activity is determined
as follows:
If the source/activity is for product (regardless of the operation type), then the default
adjusted vapor pressure for the source/activity is AVPprod.
If the source/activity is for raw material (regardless of the operation type), then the
default adjusted vapor pressure for the source/activity is AVPrm.
If the source/activity material is unspecified and it is used in a manufacturing operation,
then the default adjusted vapor pressure for the source/activity is AVPprod.
Otherwise, the default adjusted vapor pressure for the source/activity is AVPrm.
You can change the value of an AVP for an operation by changing the vapor pressure correction
factor (X) for that AVP. For example, AVPrm = Xrm x VP, so changing Xrm will change AVPrm.
Instructions and options for changing values of X are discussed below.
Default Model Selection Based on Adjusted Vapor Pressures
77
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER selects default release models when you select an operation in the pull-down
combo boxes in either the Releases or Exposures tabs. For each liquid source/activity for which
ChemSTEER conditionally defaults to a vapor model, ChemSTEER compares the activity AVP to the
adjusted vapor pressure range (see Vapor Model Activation) for the assessment.
If (AVPlow for the assessment) < (Default AVP for the source/activity (as specified in the
indented paragraph above)) < (AVPhigh for the assessment),...
...then ChemSTEER will default to the specified vapor generation and mass balance inhalation
models for the source/ activity.
Otherwise, ChemSTEER has no default model for vapor generation or vapor inhalation for the
source/ activity.
If you change an AVP for the operation or the adjusted vapor pressure range for the assessment
(i.e., AVPlow and/or AVPhigh) after the models have already been defaulted, ChemSTEER will determine
whether the change would affect the current conditional defaulting. If the change results in a switch
from being inside the range to outside or vice versa, ChemSTEER will display the following warning
message:
"The default release and exposure models have already been defaulted for the previous
AVP and Adjusted VP range, you may need to manually adjust your models based on the
new VPchem, VP correction factor, or Adjusted VP range."
If you subsequently change the conditions so that neither of the operation's AVPs are greater
than AVPlow, then the vapor model group (AVPrm, AVPprod, Xrm, Xprod, and Xother) will remain
selected and visible in the Shared Parameters/Factors subtab; however, you can manually deselect
groups of parameters on the Shared Parameters/Factors subtab.
Vapor Pressure Correction Factors
Vapor pressure correction factors (X) are used in calculating adjusted vapor pressures for an
operation as discussed above. These parameters are also inputs for vapor-related release and exposure
models. The following general defaulting rules for X apply to most vapor-related models (see the specific
model's Help topic for details on how X is used and on the available options for selecting X values in that
model).
If the source/ activity is for product (or the source/activity is not material specific and the
operation is manufacturing), then the default X for the source/activity is Xprod.
Otherwise, the default X for the source/ activity is Xrm.
Xother gives you the option of calculating or specifying a third value of X for the operation.
Below is an explanation of options for calculating or specifying X values.
Key to Parameters and Abbreviations
78
-------
ChemSTEER User Guide - Updated May 2015
a: Chemical or mixture designator for the operation (for any activities using raw
material (rm), product (prod), or other user-defined material(other))
jn: Designator for another chemical component in the mixture (limited to 5 total
other components; n is integer where 1 < n < 5; jl is for other chemical #1, ...)
X: Vapor pressure correction factor for the chemical or other component in the
mixture, dimensionless (0 < X < 1)
Y: Weight fraction of the chemical or other component in the mixture,
dimensionless (0 < Y < 1)
MW: Molecular weight of chemical or other component in the mixture, positive
number (0 < MW)
These parameters are used to perform calculations for vapor pressure correction factors for the
chemical being assessed.
Vapor Pressure Correction Factor Calculation
You can choose from the following four options to calculate the mole fraction calculation of
Xrm, Xprod, and Xother (for Xother, assume Yrm for Ya):
• Xrm = Yprod from the previous operation or 1
• X = 1
• X = Ya (assume mole fraction approximates weight fraction)
• X = (Ya / MWa) / (Ya/MWa + Yjl/MWjl + ...+ Yjn/MWjn) (mole fraction calculation using
Raoult's Law)
• X = User-defined Default
Auto Spray Painting Shared Parameters
When either the Automobile OEM Spray Coating Application operation or the Automobile
Refinish Spray Coating Application operation is selected, the Shared Parameters/Factors subtab will
display the Automotive Spray Painting shared parameters/factors, by default. You can change shared
parameter default values by double-clicking on the desired parameter in the table. The default settings
for each of these operations are summarized in the table below:
Shared Parameter/Factor
Default Setting For Automobile
OEM Spray Coating
Default Setting for Automobile
Refinish Spray Coating
Spray Gun Type
Conventional
Conventional
Overspray Control Type
Waterwash
Dry Filter
Booth Ventilation Type
Downdraft
Crossdraft
The combination of spray gun type and overspray control type determine the default
calculations in either the EPA/OPPT Automobile OEM Coating Overspray Loss Model or the EPA/OPPT
Automobile Refinish Coating Overspray Loss Model. Specifically it affects how the loss fraction of the
coating is calculated, as well as the proportions that are released to air and other media.
79
-------
ChemSTEER User Guide - Updated May 2015
The combination of spray gun type and booth ventilation type determine default calculations in
either the EPA/OPPT Automobile OEM Spray Coating Inhalation Exposure Model or the EPA/OPPT
Automobile Refinish Spray Coating Inhalation Exposure Model. These two default models estimate
exposures to non-volatile non-polyisocyanate compounds in the coating mist. An alternative model for
either the OEM or refinish operations is the EPA/OPPT Automobile Spray Coating Inhalation Exposure
Model. This model can be used to calculate exposures to polvisocvanates. Specifically the shared
parameters affect the default concentration of mist in the air used in calculating worker inhalation
exposures.
Estimating Chemical Releases Tab
You can use the Estimating Chemical Releases tab to view, update, and run the model(s) used to
calculate the releases for each of the operations' sources/activities. In this tab you may view and/or
update which models are used, view/update the specific model-related parameters, and view the model
results (estimated releases).
Changing the Model or Selecting Additional Models to Calculate a Release
For EACH Release Source/Activity of EACH OPERATION, you should first determine whether the
Release Model(s) are those that you wish to use. If desired, change the selected model(s) by clicking the
Add or Remove a Release Model button. Alternative models that are most applicable to the selected
source/activity are listed in the Available Models box. To view ChemSTEER's entire collection of release
models, click the Show All Release Models button.
Click on the model you wish to use for the selected source/activity to select it (the selected
model is highlighted) and click the Add to list button. To remove a model, select it in the Selected Models
box and click the Remove from list button. Click OK when you have finished choosing the models for the
selected source/activity.
Viewing and/or Updating a Model's Parameters
All parameters and settings used in the model are displayed in the Release Input Parameters
subtab. Click the View/Update Model Information button to access an Update window for changing any
parameter value that you wish to update. The selected model's equation(s) are displayed along with a
list of all parameters and other settings. Additional details about the models, including the equations,
logic, parameter options, and original references are available in the ChemSTEER Estimation Methods
and Models section of the User Guide.
Calculating Two Results With a Single Model
You may calculate two results from the same release model concurrently by enabling two sets of
model input parameters. This function can be used to calculate alternative releases or a range in
releases, depending on the nature of the differing input parameter values.
Some models have this capability enabled by default. To calculate a single result with these
models, simply disable one of the sets of input parameters prior to running the model.
80
-------
ChemSTEER User Guide - Updated May 2015
For additional details on how to use the dual-output model functions, read the Calculating Two
Sets of Results from a Single Model topic.
A Note About Vapor Generation Models
The following vapor generation models calculate parameters that are necessary to run a
corresponding vapor inhalation model in the Exposures tab:
EPA/OAQPS AP-42 Loading Model
EPA/OPPT Mass Transfer Coefficient Model
EPA/OPPT Penetration Model
User-Defined Vapor Generation Rate Model
In the unusual event that you wish to select more than one vapor generation model for a given
Release Activity, you should assure that the model result to be used in a corresponding Exposure Activity
vapor inhalation model is listed LAST on the Release Model(s) for Selected Activity list.
NOTE: If the adjusted vapor pressure (AVPrm or AVPprod) for the operation is less than the
preferred AVPlow or greater than the preferred AVPhigh (be sure to review the Operation Parameters
Tab -> Shared Parameters/Factors Subtab section of the User Guide), these vapor generation models
will NOT be selected as defaults for any Release Activity within that operation. You must select these
models manually.
Modifying the Target Media of Release
You may change the medium/media of release by clicking on the Modify Media of Release
button. The following receiving environmental media and alternative Media Sets (a Media Set has "or"
between two or more environmental media) are available in ChemSTEER:
Water
Water or Air
Water or Incineration
Water or Landfill
Water or Air or Incineration
Water or Air or Landfill
Water or Incineration or Landfill
Water or Air or Incineration or Landfill
Air
Air or Incineration
Air or Landfill
Air or Incineration or Landfill
Incineration
Incineration or Landfill
81
-------
ChemSTEER User Guide - Updated May 2015
Landfill
Deepwell Injection
Destroyed
Other
Certain release models have pre-defined default media of release designations which depend on
model input parameters. The models that include input parameters that affect the media of release are:
• EPA/OPPT Automobile OEM Coating Overspray Loss Model;
• EPA/OPPT Automobile Refinish Coating Overspray Loss Model;
• EPA/OPPT Electroplating Rinse Water Loss Model;
• EPA/OPPT Electroplating Spent Bath Disposal Model; and
• EPA/OPPT Solids Transfer Dust Loss Model.
If you make any changes to the media of release for these models and subsequently change
input parameters, your media of release changes will be overwritten with default designations for the
new input parameter(s). At the time you change default media of release for the models listed above,
you will receive a warning. You may also refer to the Help section for each of these models.
Entering Introductory or Operation-Specific Notes for the Releases
You may wish to record general information about the releases from an operation. One example
of this general information includes, "Releases to water are not expected." In this example, it can be
documented that, although releases are not expected from the operation, the reviewer did consider
them. This text can be used to distinguish incomplete assessments from those in which all potential
releases were considered.
This information can also be used to indicate whether multiple releases from the same
operation to the same receiving medium are expected to occur on the same days or whether they occur
on separate days.
Clicking the Introductory Notes for the Release Summary button displays a screen containing the
following check boxes:
Add "Water: not expected"
Add "IRER Note: The daily releases listed for any source below may coincide with daily releases
from the other sources to the same medium." [This note is the default for all operations]
Add "IRER Note: The daily releases listed for any source below are expected to coincide with
daily releases from the other sources to the same medium."
Add "IRER Note: The daily releases listed for any source below are not expected to coincide with
daily releases from the other sources to the same medium."
For each of the options that you check in this screen, the associated text is added to the text
box. You also may modify the text in the box, as appropriate for the operation.
82
-------
ChemSTEER User Guide - Updated May 2015
The information recorded in the Introductory Notes text box is included at the beginning of the
ENVIRONMENTAL RELEASES ESTIMATE SUMMARY section the IRER report (see IRER Format Details). If
no releases are calculated for the operation, this text will be the only item included in this section of the
IRER.
Entering Additional Notes Pertaining to Releases of Related Chemicals
Particular types of chemicals, by their nature, include additional releases beyond those that
result directly from the operation (i.e., those that are calculated for each of the operation's release
sources). For example, an assessment of a chemical compound containing a metal(s) may include
release calculations for the amount of the chemical that is sent to an incinerator; however, the metallic
components of the chemical are not destroyed by the incinerator. These components are typically
deposited in the resulting ash, which may be subsequently sent to a landfill. Amounts of this ash may
also be released to air through the stack.
These notes also allow EPA to assess particular compounds that could be formed as a result of
the chemical's release and are of special concern. For example, EPA is currently examining the potential
for compounds such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) to be
created from the release of other chemicals. ChemSTEER allows you to include an estimated quantity of
these releases for use in assessing environmental and exposure risks.
These types of additional releases can be noted and included in the assessment by clicking the
Additional Notes for the Release Summary button. ChemSTEER displays a screen containing the following
default text:
"Perfluoro/Metal component/Hydrolysis product release to WATER or AIR or
INCINERATION or LAND:
kg/site-day over * days/yr for * sites or * kg/yr
to:
from:
basis: "
If you wish to note these types of releases from your operation in the IRER (see IRER Format
Details), you MUST edit the above default text, as appropriate. You must click in the text box and click
OK before the Additional Notes will appear at the end of the ENVIRONMENTAL RELEASES ESTIMATE
SUMMARY section of the IRER.
Running the Models
Click Run Model(s) and click on the Estimated Releases subtab to view model outputs. Repeat
this process for each model used by the selected Release Activity. Repeat all steps for each Release
Activity within each Operation of the assessment.
NOTE: Be aware that changing certain parameters in the Chemical tab and Operation
Parameters subtabs will affect some of the parameter settings used in the release model estimates. Be
sure to read about Hierarchy of ChemSTEER Operations. Activities, and Models.
83
-------
ChemSTEER User Guide - Updated May 2015
Model Status Messages
The following messages are displayed at the top of the Release Input Parameters subtab:
• Model never run: The selected model has not yet been run; results are not available.
• Model was successfully run: The selected model was run; results are available.
• Model was unsuccessful: The selected model attempted to run; however, was
unsuccessful. This is usually the result of a missing parameter value. When the Run
Model(s) button is clicked, ChemSTEER displays a message indicating which parameters
were needed, but were unavailable. You must resolve the discrepancy in order to run
the model and calculate results.
• Model parms were changed, please re-run the models: At least one parameter was
changed since the model was last run; you must re-run the model in order to update the
results.
Estimating Chemical Exposures Tab
You can use the Estimating Chemical Exposures tab to view, update, and run the model(s) used
to calculate the dermal and/or inhalation exposures for each of the operations' activities. In this tab you
may view and/or update which models are used, view/update the specific model-related parameters,
and view the model results (estimated exposures). The Respirator Class and Monitoring Review subtab is
read-only and the fields are described under the IRER Format Details topic.
Changing the Model or Selecting Additional Models to Calculate an Exposure
For EACH Exposure Activity of EACH OPERATION, you should first determine whether the
Exposure Model(s) are those that you want to use. If desired, change the selected model(s) by clicking
the Add or Remove a Release Model button and choosing an alternative from either the Dermal Model
and/or Inhalation Model combo boxes.
Viewing and/or Updating a Model's Parameters
When a model you want to use is shown next to the Dermal Exposure or Inhalation Exposure
Model label, you may view the parameters used in the model and, if needed, click the View/Update
Model Information button to access an Update window for changing any parameter values that you wish
to update.
All parameters and settings used in the dermal and inhalation exposure models are displayed in
the Dermal Model Input Parameters and the Inhalation Model Input Parameters subtabs, respectively.
Click the View/Update Model Information button to access an Update window for changing any
parameter value that you wish to update. The selected model's equation(s) are displayed along with a
list of all parameters and other settings. Additional details about the models, including the equations,
logic, parameter options, and original references are available in the ChemSTEER Estimation Methods
and Models section of the User Guide.
The Update window also contains an Uncertainty checkbox. This is primarily used by EPA
reviewers and is an indication that there is some level of uncertainty associated with the inhalation
exposure estimate included in the assessment (e.g., it is based a model, regulatory limit, or data that is
84
-------
ChemSTEER User Guide - Updated May 2015
not specific to the industry). As a default, the Uncertainty is checked for each inhalation exposure
estimate.
Calculating Two Results With a Single Model
You may calculate two results from the same exposure model concurrently by enabling two sets
of model input parameters. This function can be used to calculate alternative exposures or a range in
exposures, depending on the nature of the differing input parameter values.
Some models have this capability enabled by default. To calculate a single result with these
models, simply disable one of the sets of input parameters prior to running the model.
For additional details on how to use the dual-output model functions, read the Calculating Two
Sets of Results from a Single Model topic.
A Note About Vapor Inhalation Models
The following vapor inhalation models have input parameters that are determined from values
set or calculated by corresponding vapor generation models in the Releases tab:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
In the unusual event that you select more than one vapor generation model for a given Release
Activity in the Releases tab, you should assure that the model result to be used in the corresponding
Exposure Activity vapor inhalation model is listed LAST on the Release Model(s) for Selected Activity list.
NOTE: If the adjusted vapor pressure (AVPrm or AVPprod) for the operation is less than the
preferred AVPlow or greater than the preferred AVPhigh (be sure to review the Operation Parameters
Tab -> Shared Parameters/Factors Subtab section), the vapor generation and vapor inhalation models
will NOT be selected as defaults for any source/activity within that operation. You must select these
models manually.
Entering an Introductory or Operation-Specific Notes for the Inhalation Exposures
You may wish to record general information about the inhalation exposures in an operation. An
example of this of this general information includes, "Inhalation is negligible (VP < 0.001 torr)". In this
example, it can be documented that, although inhalation exposures are not expected in the operation,
the reviewer did consider them. This text can be used to distinguish incomplete assessments from those
in which all potential inhalation exposures were considered.
Clicking the Introductory Notes for the Inhalation Summary button in the Inhalation Model Input
Parameters subtab displays a screen containing the following option in a drop-down box: "negligible (VP
< 0.001 torr)".
When this option is selected, the text is added to the text box. You also may modify the text in
the box, as appropriate for the operation.
85
-------
ChemSTEER User Guide - Updated May 2015
The information that is recorded for the Introductory Notes text box is included in the
OCCUPATIONAL EXPOSURES ESTIMATE SUMMARY - Inhalation section of the IRER report (see IRER
Format Details). If no inhalation exposures are calculated for the operation, this text will be the only
item included in this section of the IRER (any calculated dermal exposures will also be displayed in this
section).
Entering an Introductory or Operation-Specific Notes for the Dermal Exposures
You may wish to record general information about the dermal exposures in an operation. An
example of this of this general information includes, "Dermal exposures are not assessed (corrosive
chemical)". In this example, it can be documented that, although dermal exposures are not expected in
the operation, the reviewer did consider them. This text can be used to distinguish incomplete
assessments from those in which all potential dermal exposures were considered.
Clicking the Introductory Notes for the Dermal Summary button in the Dermal Model Input
Parameters subtab displays a screen containing the following options in a drop-down box:
• Negligible - Corrosives (pH > 12, pH < 2)
• Negligible - Materials at temperatures > 140 F (60 C)
• Non-quantifiable (Some surface contact may occur if manually transferred) - In cast
solids (e.g., molded plastics) or in matrices (e.g., extruded pellets)
• Non-quantifiable - "Dry" surface coatings (e.g., fiber spin finishes)
• Non-quantifiable - Gases/vapors (some contact may occur in the absence of protective
clothing)
When one of these options is selected, the text is added to the text box. You also may modify
the text in the box, as appropriate for the operation.
The information that is recorded for the Introductory Notes text box is included in the
OCCUPATIONAL EXPOSURES ESTIMATE SUMMARY - Dermal section of the IRER report (see IRER Format
Details). If no inhalation exposures are calculated for the operation, this text will be the only item
included in this section of the IRER (any calculated dermal exposures will also be displayed in this
section).
Update Operation Total Number of Workers Exposed Button
You may click the Update Operation Total Number of Workers Exposed button to view the
update window containing an operation worker activity/exposures summary table. You may also change
the default Operation Total Number of Workers estimated value that is calculated for the operation
(default is the sum of each activity's total number of workers). Be sure to enter other information about
the estimated total number of workers in the Basis box provided on this window.
NOTE: Each time you modify the operation's activities or run the exposure models, all values in
the summary table will be updated, including the Operation Total Number of Workers estimated value if
you entered an alternate number. Read below for additional details.
The following parameters are displayed on the update window:
86
-------
ChemSTEER User Guide - Updated May 2015
Activity (read-only): Listing of activities with occupational exposure for the operation.
Route (read-only): Route of exposure, inhalation and/or dermal, for the model(s) with the
highest number of total workers for the activity.
Note: The following logic is used to determine the most appropriate route of exposure
forming the basis for the total number of workers calculations:
• If there is the same Activity total number of workers (NSx NWexp) for inhalation and
dermal, the Inhalation and Dermal will appear in the Route column.
• If there is the sam e Activity total number of workers (NSx NWexp) for inhalation and
dermal, but the values for NS and NWexp are different, then Inhalation will appear in
the Route column.
• If the Activity total number of workers (NSx NWexp) is greater for one route than the
other, then only the route with the larger Activity total number of workers (NS x NWexp)
will appear in the Route column.
Number of sites (read-only): number of sites, NS, for the model(s) with the highest number of
total workers for the activity.
Number of workers per site (read-only): number of workers, NWexp, for the model(s) with the
highest number of total workers for the activity.
Activity total number of workers (read-only): product of the numbers of workers and sites (NS x
NWexp) for the model(s) with the highest number of total workers for the activity.
Note: the Activity total number of workers (NS x NWexp) will be from the larger of Output 1
or Output 2.
Operation total number of the workers default (sum from all activities) (read-only): sum of all
products of the numbers of workers and sites (NS x NWexp) from the activities in the table.
Operation total number of workers estimated: initial default = sum of all products of the
numbers of workers and sites (NS x NWexp) from the table. You may change this value to override the
default.
If no model is run for an activity, all values in that row will display zeros. The Operation
total number of the workers default will be recalculated when a new activity is added,
when an activity is removed, when the exposure model Yes/No indicator on the
Sources/Activities subtab is changed, and each time models are added, removed, or run
for the operation. If the Operation total number workers default (sum from all activities)
has changed, the Operation total number of workers estimated is reset to the default.
When the Operation total number of workers estimated has been reset, the Basis text
will remain visible on the update window (for future use or reference) but will be grayed
out (read-only) and will not appear on reports. You can restore the Basis text for reports
87
-------
ChemSTEER User Guide - Updated May 2015
and modify by clicking on the Operation total number of workers estimated or by
clicking on the Basis text.
Running the Models
Click Run Model(s) and click on the Estimated Releases subtab to view model(s) outputs. Repeat
this process for each model used by the selected Exposure Activity. Repeat all steps for each Exposure
Activity within each Operation of the assessment.
NOTE: Be aware that changing certain parameters in the Chemical tab and Operation
Parameters subtabs will affect some of the parameter settings used in the exposure model estimates. Be
sure to read about Hierarchy of ChemSTEER Operations. Activities, and Models.
Model Status Messages
The following messages are displayed at the top of the Dermal/Inhalation Model Input
Parameters subtabs:
• Model never run: The selected model has not yet been run; results are not available.
• Model was successfully run: The selected model was run; results are available.
• Model was unsuccessful: The selected model attempted to run; however, was
unsuccessful. This is usually the result of a missing parameter value. When the Run
Model(s) button is clicked, ChemSTEER displays a message indicating which parameters
were needed, but were unavailable. You must resolve the discrepancy in order to run
the model and calculate results.
• Model parms were changed, please re-run the models: At least one parameter was
changed since the model was last run; you must re-run the model in order to update the
results.
Optional Information Tab
The Optional Information tab allows the user to record EPA-related and other information, if
applicable.
This tab contains several input screens that are each accessible by selecting a set of inputs from
the combo box.
Some general, all-purpose information screens include:
• MSDS/Label/Exposure Limits - this screen contains subtabs for recording MSDS
requirements, relevant exposure limits, and LVE PPE (LVE PPE pertains to EPA-
assessments of Low Volume Exemption (LVE) submissions);
• Pollution Prevention Considerations; and
• Notes and Key Assumptions used in the assessment.
Some of the input screens are designed to serve EPA-related assessments, including:
88
-------
ChemSTEER User Guide - Updated May 2015
• SAT Data;
• Exposure-based Criteria;
ChemSTEER may "double count" workers in select categories. For a single activity with dual
outputs, 52 workers at 1.5 and 15 mg/day is considered 52 workers at 1-10 mg/day and 52 workers at
>10 mg/day, while 52 workers at 2 and 6 mg/day is considered 52 workers at 1-10 mg/day.
• Physical State and Misc CRSS Info, Other uses, Occupational Exposure Rating, and
Consumer Use (see additional information regarding the Occupational Exposure Rating
below); and
• Special LVE Considerations.
Occupational Exposure Ratings (OERs)
The Occupational Exposure Rating (OER) is an assessment-level read-only text box that is
displayed when you select Physical State and Misc CRSS Info, Other Uses, Occupational Exposure Rating,
and Consumer Use.
The OER is the combination of the Numerical Ratings for Route and Dose and the Letter Ratings
for Number of Workers, as defined in the table below:
Rating
Criteria
Numerical Ratings for Route and Dose
NR
No occupational exposure assessment (e.g., low health concern). Inhalation and dermal routes not
assessed per SAT.
0-1
No exposure via routes assessed (=0 exposed workers). Each inhalation or dermal model estimate is 0 or
has 0 workers, or there are no inhalation or dermal models but SAT requires inhalation or dermal
assessments.
1
Dermal only (no inhalation, i.e., no inhalation models or inhalation estimates are 0 and at least one
dermal model is non-zero)
1-2
Inhalation < 1 mg/day (considering each individual inhalation exposure)
2
Inhalation 1-10 mg/day (considering each individual inhalation exposure)
2-3
Inhalation > 10 mg/day (considering each individual inhalation exposure)
Letter Ratings for Number of Workers
A
<10 workers exposed for all assessed operations*
B
<100 workers exposed for all assessed operations*
C
<1000 workers exposed for all assessed operations*
D
>1000 workers exposed for all assessed operations*
* The total workers for the assessment is the sum of the Operation total number of workers estimated for all
operations in the assessment. Go to the Estimating Chemical Exposures Tab topic of this User Guide (the
Update Operation Total Number of Workers Exposed Button section) for more information.
Note that the exposure letter rating is not needed with numerical ratings associated with no
exposure (i.e., NR and 0-1)). The highest possible numerical rating should be used when multiple criteria
are met. For example, an assessment with dermal estimates, which produce a rating of 1, and inhalation
estimates of both 0.5 mg/day, which produces a rating of 1-2, and 50 mg/day, which produces a rating
89
-------
ChemSTEER User Guide - Updated May 2015
of 2-3, would be assigned a 2-3 rating (with the letter rating assigned based on the total number of
workers estimated).
The OER is updated each time exposure models are run, when exposure models are added or
removed (including when the exposure activity Yes/No indicator on the Sources/Activities tab is
changed, when activities and operations are added or removed), and when you have specified the total
number of workers estimated.
Reports Tab
A reports tab has been included in the September 30, 2013 version of ChemSTEER to signify the
end of the assessment process. These options are identical to those listed in the File/ Reports menu.
View the Generating and Viewing Summary Reports section for a summary of options.
90
-------
ChemSTEER User Guide - Updated May 2015
Release Sources and Exposure Activities
In ChemSTEER, the term Source/Activity refers to sources and activities in an operation that
can/do/will cause environmental releases and/or worker exposures. Most Sources/Activities have one
or more default models that ChemSTEER uses to estimate releases and exposures. Choosing appropriate
Sources/Activities allow you to access the models to make these estimates. Note: you may include up to
20 sources/activities within each operation included in the assessment.
Many industry-specific operations in ChemSTEER have preselected default Sources/Activities
based on the sources and activities that are expected to occur in these operations. The user-defined
operations require that you select the relevant Sources/Activities to assess.
Some Sources/Activities are specific to a particular industry (e.g., the Automotive Refinish Spray
Coating Application source/activity), while other sources/activities are "broadly applicable" across many
workplaces (e.g., the Loading Liquid Product into Drums or the Sampling Solid Raw Material
sources/activities). The broadly applicable sources/activities available in ChemSTEER are only a subset of
all possible sources and activities and cover those that are often overlooked or considered to be non-
routine or insignificant.
When none of the other available Sources/Activities seem to cover a particular source/activity
that you wish to assess, you may choose from the Sources/Activities listed under the Miscellaneous
Sources/Activities category, which allow you the greatest flexibility in using ChemSTEER to estimate
releases and/or exposures (i.e., these miscellaneous Sources/Activities allow you to choose the most
appropriate release/exposure methods and models to use in the calculations).
Each selected Source/Activity activates one or more equations that represent methods and
models that will quantify the release and/or exposure estimate(s). The Default Model Processing (DMP)
status indicates whether each of the operation's selected sources/activities have been "processed" by
ChemSTEER and have had their default models selected. The DMP status is displayed in the Release DMP
and Exposure DMP columns of the Sources/Activities subtab of the Operations tab. Be sure to read more
about ChemSTEER's hierarchy of functions, in particular the various DMP status indicators (click on the
Default Model Processing link within Hierarchy of ChemSTEER Operations. Activities, and Models).
You can read more about the default methods and models, as well as the most appropriate
alternatives, for each of the Sources/Activities by selecting one of the categories below to view the list
of associated sources/activities. You may then select any of the sources/activities in the category list to
view detailed information about that source/activity.
• Loading Liquids into Transport Containers/Vessels
• Loading Solids into Transport Containers/Vessels
• Unloading Liquids from Transport Containers/Vessels
• Unloading Solids from Transport Containers/Vessels
• Cleaning Liquid Residuals from Transport Containers/Vessels
• Cleaning Solid Residuals from Transport Containers/Vessels
91
-------
ChemSTEER User Guide - Updated May 2015
• Sampling Liquids
• Sampling Solids
• Equipment Cleaning Losses of Liquids
• Equipment Cleaning Losses of Solids
• Unit Operations and Processes
• Vapor Release from Transfer Operations
• Miscellaneous Sources/Activities
• Automobile Spray Coating
• Generic Coating Applications
• Electroplating Bath Additives
• Recirculating Water-Cooling Tower Additives
Loading Liquids into Transport Containers/Vessels
Definition
The loading of liquid product or raw material into transport containers/vessels that results in a
release of the chemical and/or worker exposure to the chemical.
The following release sources/exposure activities may be selected for operations in which a
liquid material containing the chemical is loaded into transport containers:
Loading
Liquid
Product Into Bottles
Loading
Liquid
Product Into Small Containers
Loading
Liquid
Product Into Drums
Loading
Liquid
Product Into Totes
Loading
Liquid
Product Into Tank Trucks
Loading
Liquid
Product Into Rail Cars
Loading
Liquid
Product Into Containers
Loading
Liquid
Raw Materials Into Containers
Loading
Liquid
into Storage/Transport Vessels (User-defined)
The following table provides information on ChemSTEER default volumes and range of volumes
for each type of container:
92
-------
ChemSTEER User Guide - Updated May 2015
Vessel Name
Default Volume (Vc)
[gal]
Range of Volumes
[gal]
Loading Liquid Product Into Bottles
1
<5
Loading Liquid Product Into Small Containers
5
> 5 to < 20
Loading Liquid Product Into Drums
55
> 20 to <100
Loading Liquid Product Into Totes
550
> 100 to < 1,000
Loading Liquid Product Into Tank Trucks
5,000
> 1,000 to < 10,000
Loading Liquid Product Into Rail Cars
20,000
> 10,000
Loading Liquid Product Into Containers
User-Defined
User-Defined
Loading Liquid into Storage/Transport Vessels (User-defined)
User-Defined
User-Defined
Source: portions from USEPA, 1991, Table 4-11.
For additional information on other container-specific parameters, go to Container Parameters
Guidance-
Default Release
The amount of chemical released to air from this source is calculated using the EPA/OAQPS AP-
42 Loading Model.
NOTE: the air release model above is only defaulted if the selected operation's adjusted vapor
pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the Operation
Parameters Tab Shared Parameters/Factors Subtab topic for more information. If the
operation AVP is outside of the preferred range, there is no model for calculating releases to air
from this source.
No default model exists for releases to non-air media from this source in ChemSTEER. OPPT
assumes that releases from this source are insignificant when compared to other sources. If a release is
expected, you must choose an appropriate model or specify a user-defined release to these media (see
Other Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Mass Balance Inhalation Model.
NOTE: the inhalation exposure model above is only defaulted if the selected operation's
adjusted vapor pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the
Operation Parameters Tab Shared Parameters/Factors Subtab topic for more information. If
the operation AVP is outside of the preferred range, there is no model for calculating worker
inhalation exposures during this activity.
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT 2-Hand Dermal Contact with Liquid Model.
Other Release and Exposure Models
93
-------
ChemSTEER User Guide - Updated May 2015
The default release and exposure models assume that the most significant release and exposure
during the loading operation is from the displacement of air containing chemical vapor as a
container/vessel is filled with liquid. You may have information and/or data that better represents the
chemical releases and/or the worker exposures that occur during loading of liquid product into bottles.
You may select alternative models to the default models described above to estimate chemical releases
and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT 1-Hand Dermal Contact with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Unloading Liquids from Transport Containers/Vessels
Definition
The unloading of liquid product or raw material from transport containers/vessels that results in
a release of the chemical and/or worker exposure to the chemical.
The following release sources/exposure activities may be selected for operations in which a
liquid material containing the chemical is loaded into transport containers:
• Unloading Liquid Raw Material from Bottles
• Unloading Liquid Raw Material from Small Containers
• Unloading Liquid Raw Material from Drums
94
-------
ChemSTEER User Guide - Updated May 2015
• Unloading Liquid Raw Material from Totes
• Unloading Liquid Raw Material from Tank Trucks
• Unloading Liquid Raw Material from Rail Cars
• Unloading Liquid Raw Material from Containers
• Unloading Liquid Product from Containers
• Unloading Liquid from Storage/Transport Vessels (User-defined)
The following table provides information on ChemSTEER default volumes and range of volumes
for each type of container:
Vessel Name
Default Volume (Vc)
[gal]
Range of Volumes
[gal]
Unloading Liquid Raw Material from Bottles
1
<5
Unloading Liquid Raw Material from Small Containers
5
> 5 to < 20
Unloading Liquid Raw Material from Drums
55
> 20 to <100
Unloading Liquid Raw Material from Totes
550
> 100 to < 1,000
Unloading Liquid Raw Material from Tank Trucks
5,000
> 1,000 to < 10,000
Unloading Liquid Raw Material from Rail Cars
20,000
> 10,000
Unloading Liquid Product Into Containers
User-Defined
User-Defined
Unloading Liquid into Storage/Transport Vessels (User-defined)
User-Defined
User-Defined
Source: portions from USEPA, 1991, Table 4-11.
For additional information on other container-specific parameters, go to Container Parameters
Guidance-
Default Release
The EPA/OAQPS AP-42 Loading Model is the default for calculating releases of the chemical to
air during unloading. It is assumed that as the container is unloading, another is being loaded. The
default model provides a more conservative estimate of chemical releases that occur during this activity.
NOTE: the air release model above is only defaulted if the selected operation's adjusted vapor
pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the Operation
Parameters Tab Shared Parameters/Factors Subtab topic for more information. If the
operation AVP is outside of the preferred range, there is no model for calculating releases to air
from this source.
No default model exists for releases to non-air media from this source in ChemSTEER. OPPT
assumes that releases from this source are insignificant when compared to other sources. If a release is
expected, you must choose an appropriate model or specify a user-defined release to these media (see
Other Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Mass Balance Inhalation Model
95
-------
ChemSTEER User Guide - Updated May 2015
NOTE: the inhalation exposure model above is only defaulted if the selected operation's
adjusted vapor pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the
Operation Parameters Tab -> Shared Parameters/Factors Subtab topic for more information. If
the operation AVP is outside of the preferred range, there is no model for calculating worker
inhalation exposures during this activity.
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT 2-Hand Dermal Contact with Liquid Model
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during the unloading operation is from the displacement of air containing chemical vapor as another
container/vessel is filled with liquid. You may have information and/or data that better represents the
chemical releases and/or the worker exposures that occur during unloading of liquid raw material from
bottles. You may select alternative models to the default models described above to estimate chemical
releases and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OPPT Penetration Model (for indoor activities, air speed is < 100 feet/min)
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed >100
feet/min)
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT 1-Hand Dermal Contact with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• EPA/OPPT 2-Hand Dermal Immersion with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
96
-------
ChemSTEER User Guide - Updated May 2015
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Loading Solids into Transport Containers/Vessels
Definition
The loading of solid raw material or product material into transport containers that results in a
release of the chemical and/or worker exposure to the chemical.
The following release sources/exposure activities may be selected for operations in which a solid
material containing the chemical is loaded into transport containers:
• Loading Solid Product into Transport Containers
• Loading Solid Raw Materials into Transport Containers
• Loading Solids into Storage/Transport Vessels (User-defined)
The following table provides information on ChemSTEER default volumes and range of volumes
for each type of container:
Vessel Name
Default Volume (Vc)
[gal]
Range of Volumes
[gal]
Loading Solid Product into Transport Containers
User-Defined
None
Loading Solid Raw Material into Transport Containers
Loading Solids into Storage/Transport Vessels (User-defined)
For additional information on container-specific parameters, go to Container Parameters
Guidance-
Default Release
Multi-media Release: The amount of chemical released to both air and non-air media as a result
of dust generated by this activity is calculated using the EPA/OPPT Solids Transfer Dust Loss Model. This
model apportions amounts of the dust collected to various media, determined by the control technology
(if applicable).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using one of
the following models:
• If the amount of product packaged per site-day (i.e., MCi x Ned in the Container
Parameters subtab of the Operation Parameters tab) < 54 kg/site-day, then the
EPA/OPPT Small Volume Solids Handling Inhalation Model is used as a default.
97
-------
ChemSTEER User Guide - Updated May 2015
• If the amount of product packaged per site-day > 54 kg/site-day, then either the OSHA
Respirable PNOR PEL-Limiting Model or OSHA Total PNOR PEL-Limiting Model may be
chosen as a default.
NOTE: If the daily amount of material loaded was not calculated by ChemSTEER before the
inhalation exposure is calculated, the daily amount of material throughput from the Mass
Balance calculations will be used.
If the throughput was not calculated, the OSHA Total PNOR PEL-Limiting Model will be used as a
default.
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model.
Other Release and Exposure Models
The default exposure models assume that the most significant exposure during the loading
operation is from the generation of dusts containing chemical as a container/vessel is filled with solids.
You may have information and/or data that better represents the chemical releases and/or the worker
exposures that occur during loading of solid product into containers. You may select alternative models
to the default models described above to estimate chemical releases and worker exposures.
The following model may be used to estimate releases that occur from this source. More than
one release model may be used at one time to estimate releases, as appropriate.
• User-Defined Loss Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• User-Defined Inhalation Model
The following alternative dermal exposure model may be used to estimate the worker exposure
that occurs as a result of performing this activity:
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Unloading Solids from Transport Containers/Vessels
98
-------
ChemSTEER User Guide - Updated May 2015
Definition
The unloading of solid raw material or product material into transport containers that results in
a release of the chemical and/or worker exposure to the chemical.
The following release sources/exposure activities may be selected for operations in which a solid
material containing the chemical is unloaded from transport containers:
• Unloading Solid Raw Materials from Transport Containers
• Unloading Solid Product from Transport Containers
• Unloading Solids from Storage/Transport Vessels (User-defined)
The following table provides information on ChemSTEER default volumes and range of volumes
for each type of container:
Vessel Name
Default Volume (Vc)
[gal]
Range of Volumes
[gal]
Unloading Solid Raw Material from Transport Containers
User-Defined
None
Unloading Solid Product from Transport Containers
Unloading Solids from Storage/Transport Vessels (User-defined)
For additional information on container-specific parameters, go to Container Parameters
Guidance
Default Release
Multi-media Release: The amount of chemical released to both air and non-air media as a result
of dust generated by this activity is calculated using the EPA/OPPT Solids Transfer Dust Loss Model. This
model apportions amounts of the dust collected to various media, determined by the control technology
(if applicable).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using one of
the following models:
• If the amount of raw material unloaded per site-day (i.e., MCi x Ned in the Container
Parameters subtab of the Operation Parameters tab) < 54 kg/site-day, then the
EPA/OPPT Small Volume Solids Handling Inhalation Model is used as a default.
• If the amount of raw material unloaded per site-day > 54 kg/site-day, then either the
OSHA Total PNOR PEL-Limiting Model or OSHA Respirable PNOR PEL-Limiting Model
may be chosen as a default.
NOTE: If the daily amount of material unloaded was not calculated by ChemSTEER before the
inhalation exposure is calculated, the daily amount of material throughput from the Mass
Balance calculations will be used.
99
-------
ChemSTEER User Guide - Updated May 2015
If the throughput was not calculated, the OSHA Total PNOR PEL-Limiting Model will be used as a
default.
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model.
Other Release and Exposure Models
The default exposure models assume that the most significant exposure during the unloading
operation is from the generation of dusts containing chemical as a container/vessel containing solids is
emptied. You may have information and/or data that better represents the chemical releases and/or the
worker exposures that occur during unloading of solid raw material from containers. You may select
alternative models to the default models described above to estimate chemical releases and worker
exposures.
The following model may be used to estimate releases that occur from this source. More than
one release model may be used at one time to estimate releases, as appropriate.
• User-Defined Loss Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Cleaning Liquid Residuals from Transport Containers/Vessels
Definition
The cleaning of raw material or product residues from "empty" transport containers/vessels
with a liquid cleaning medium that results in a release of the chemical and/or worker exposure to the
100
-------
ChemSTEER User Guide - Updated May 2015
chemical. This release source/worker activity is also relevant to the disposal of liquid residues with the
empty container/vessel.
The following release sources/exposure activities may be selected for operations in which a
liquid material containing the chemical is cleaned from or disposed with "empty" transport containers:
Activities for Raw Materials and Products:
• Cleaning Liquid Residuals from Bottles Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Small Containers Used to Transport the Raw
Material/Product
• Cleaning Liquid Residuals from Drums Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Totes Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Tank Trucks Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Rail Cars Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Containers Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Storage/Transport Vessels (User-defined)
The following table provides information on ChemSTEER default volumes and range of volumes
for each type of container:
Vessel Name
Default Volume (Vc)
[gal]
Range of Volumes
[gal]
Unloading Liquid Raw Material from Bottles
1
<5
Unloading Liquid Raw Material from Small Containers
5
> 5 to < 20
Unloading Liquid Raw Material from Drums
55
> 20 to <100
Unloading Liquid Raw Material from Totes
550
> 100 to < 1,000
Unloading Liquid Raw Material from Tank Trucks
5,000
> 1,000 to < 10,000
Unloading Liquid Raw Material from Rail Cars
20,000
> 10,000
Unloading Liquid Product Into Containers
User-Defined
User-Defined
Unloading Liquid into Storage/Transport Vessels (User-defined)
User-Defined
User-Defined
Source: portions from USEPA, 1991, Table 4-11.
For additional information on other container-specific parameters, go to Container Parameters
Guidance-
Default Releases
Air Release:
It is assumed that cleaning activities for bottles, small containers, drums, and totes are
performed indoors (i.e., air speed is < 100 feet/min). The amount of chemical release from these
sources is thus calculated using the EPA/OPPT Penetration Model.
101
-------
ChemSTEER User Guide - Updated May 2015
For tank trucks and rail cars, it is assumed that the cleaning activities are performed outdoors
(i.e., air speed is > 100 feet/min). The amount of chemical release from this source is thus calculated
using the EPA/OPPT Mass Transfer Coefficient Model.
NOTE: the air release models above are only defaulted if the selected operation's adjusted
vapor pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the Operation
Parameters Tab Shared Parameters/Factors Subtab topic for more information. If the
operation AVP is outside of the preferred range, there is no model for calculating releases to air
from this source.
Non-Air Release:
Release of the residual raw material/product in the "empty" container is calculated
using the either the EPA/OPPT Small Container Residual Model. EPA/OPPT Drum Residual Model, or
EPA/OPPT Bulk Transport Residual Model, depending on the container size.
The following table summarizes the default air and non-air release models for each type
of container:
Vessel Name
Default Air Release Models
Default Non-Air Release Models
Bottles
EPA/OPPT Penetration Model
EPA/OPPT Small Container Residual Model
Small Containers
Drums
EPA/OPPT Drum Residual Model
Totes
EPA/OPPT Bulk Transport Residual Model
Tank Truck
EPA/OPPT Mass Transfer Coefficient Model
Rail Car
Containers
No default model - If a release to air is
expected, you must choose an appropriate
model or specify a user-defined release to air
(see Other Release and Exposure Models,
below).
EPA/OPPT Drum Residual Model
Storage/Transport
Vessels (User-
Defined)
EPA/OPPT Penetration Model
EPA/OPPT Drum Residual Model
Default Exposures
Worker inhalation exposure to the chemical resulting from these activities is calculated using
the EPA/OPPT Mass Balance Inhalation Model.
NOTE: In order to utilize the above vapor inhalation model, you must select and run a vapor
generation release model for this source/activity in order to obtain the necessary input
parameters for this model.
NOTE: the inhalation exposure model above is only defaulted if the selected operation's
adjusted vapor pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the
Operation Parameters Tab Shared Parameters/Factors Subtab topic for more information. If
102
-------
ChemSTEER User Guide - Updated May 2015
the operation AVP is outside of the preferred range, there is no model for calculating worker
inhalation exposures during this activity.
Worker dermal exposure to the chemical resulting from these activities is calculated using the
EPA/OPPT 2-Hand Dermal Contact with Liquid Model.
The following table summarizes the default inhalation and dermal exposure models for
each type of container:
Vessel Name
Default Inhalation Exposure Models
Default Dermal Exposure Models
Bottles
EPA/OPPT Mass Balance Inhalation Model
EPA/OPPT 2-Hand Dermal Contact with
Liquid Model
Small Containers
Drums
Totes
Tank Truck
Rail Car
Containers
Storage/Transport
Vessels (User-
Defined)
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during the cleaning operation is from disposal of liquid residues containing the chemical and from the
evaporation of volatile liquid residues containing chemical vapor. You may have information and/or data
that better represents the chemical releases and/or the worker exposures that occur during cleaning
and disposal of liquid bottle residues. You may select alternative models to the default models described
above to estimate chemical releases and worker exposures.
The following table presents alternative models may be used to estimate releases that occur
from this source. These models may also be selected in addition to the default, as appropriate.
103
-------
ChemSTEER User Guide - Updated May 2015
Vessel Name
Other Release Models
Bottles
EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities;
air speed >100 feet/min)
EPA/OAQPS AP-42 Loading Model
EPA/OPPT Drum Residual Model
User-Defined Loss Rate Model
User-Defined Vapor Generation Rate Model
Small Containers
Totes
Drums
EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities;
air speed >100 feet/min)
EPA/OAQPS AP-42 Loading Model
Storage/Transport Vessels (User-Defined)
User-Defined Loss Rate Model
User-Defined Vapor Generation Rate Model
Tank Truck
EPA/OPPT Penetration Model (for indoor activities; air speed <100
feet/min)
EPA/OAQPS AP-42 Loading Model
User-Defined Loss Rate Model
User-Defined Vapor Generation Rate Model
Rail Car
Containers
EPA/OPPT Penetration Model (for indoor activities; air speed <100
feet/min)
EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities;
air speed >100 feet/min)
EPA/OAQPS AP-42 Loading Model
EPA/OPPT Small Container Residual Model
EPA/OPPT Bulk Transport Residual Model
User-Defined Loss Rate Model
User-Defined Vapor Generation Rate Model
The following alternative inhalation and dermal exposure models may be used to estimate the
worker exposure that occurs as a result of performing these activities:
104
-------
ChemSTEER User Guide - Updated May 2015
Vessel Name
Other Inhalation Exposure Models
Other Dermal Exposure Models
Bottles
OSHA PEL-Limiting Model for Substance-
EPA/OPPT 1-Hand Dermal Contact with
Liauid Model
US EPA Memo entitled Updating
CEB's Method for Screening-
Level Assessments of Dermal
Exposure, September 2013.
Small Containers
Drums
Totes
Tank Truck
Rail Car
Specific Vapors
User-Defined Inhalation Model
EPA/OPPT 2-Hand Dermal Immersion
with Liauid Model
US EPA Memo entitled Updating
CEB's Method for Screening-
Level Assessments of Dermal
Exposure, September 2013.
User-Defined Dermal Model
Containers
Storage/Transport Vessels
(User-Defined)
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Cleaning Solid Residuals from Transport Containers/Vessels
Definition
The cleaning of solid raw material or product residues from "empty" containers that results in a
release of the chemical and/or worker exposure to the chemical. This release source/worker activity is
also relevant to the disposal of solid residues with the empty container.
The following release sources/exposure activities may be selected for operations in which a solid
material containing the chemical is cleaned from or disposed with "empty" transport containers:
• Cleaning Solid/Powder Residuals from Container Used to Transport the Raw Material
• Cleaning Solid/Powder Residuals from Container Used to Transport the Product
• Cleaning Solid/Powder Residuals from Storage/Transport Vessels (User-defined)
For additional information on container-specific parameters, go to Container Parameters
Guidance-
Default Releases
Release of the residual raw material to non-air media from the "empty" container is calculated
using the EPA/OPPT Solid Residuals in Transport Containers Model.
105
-------
ChemSTEER User Guide - Updated May 2015
No default model exists for releases to air from these sources in ChemSTEER. If a release to air is
expected, you must choose an appropriate model or specify a user-defined release to air (see Other
Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using one of
the following models:
• If the daily amount of raw material in the containers (i.e., MCi x Ned in the Container
Parameters subtab of the Operation Parameters tab) < 54 kg/site-day, then the
EPA/OPPT Small Volume Solids Handling Inhalation Model is used as a default.
• If the daily amount of raw material in the containers > 54 kg/site-day, then either the
OSHA Total PNOR PEL-Limiting Model or OSHA Respirable PNOR PEL-Limiting Model
may be chosen as a default.
NOTE: If the daily amount of raw material in the containers was not calculated by ChemSTEER
before the inhalation exposure is calculated, the daily amount of material throughput from the
Mass Balance calculations will be used.
If the throughput was not calculated, the OSHA Total PNOR PEL-Limiting Model will be used as a
default.
EPA Assessment Policy Recommendation: It is recommended that the amount of solid residue
that is cleaned from or disposed with the emptied container (i.e., the loss fraction x MCi x Ned)
be used to select the default inhalation model, instead using the total amount in the container
before it is emptied (MCi x Ned), as described above.
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model.
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during the cleaning operation is from disposal of solid residues containing the chemical and from the
generation of dust containing chemical. You may have information and/or data that better represents
the chemical releases and/or the worker exposures that occur during cleaning and disposal of solid raw
material container residues. You may select alternative models to the default models described above to
estimate chemical releases and worker exposures.
The following alternative model may be used to estimate releases that occur from this source.
The model may also be selected in addition to the default, as appropriate.
• User-Defined Loss Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
106
-------
ChemSTEER User Guide - Updated May 2015
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Sampling Liquids
Definition
The sampling of liquids that results in a release of the chemical and/or worker exposure to the
chemical.
The following release sources/exposure activities may be selected for operations in which a
liquid material containing the chemical is sampled:
• Sampling Liquid Raw Material
• Sampling Liquid Product
• Sampling Liquids
Default Releases
It is assumed that these activities are performed indoors (i.e., air speed is < 100 feet/min) and
the EPA/OPPT Penetration Model is used as a default for releases to air.
NOTE: the air release model above is only defaulted if the selected operation's adjusted vapor
pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the Operation
Parameters Tab Shared Parameters/Factors Subtab topic for more information. If the
operation AVP is outside of the preferred range, there is no model for calculating releases to air
from this source.
No default model exists for releases to non-air media from these sources in ChemSTEER. OPPT
assumes that releases from these sources are insignificant when compared to other sources. If a release
is expected, you must choose an appropriate model or specify a user-defined release to these media
(see Other Release and Exposure Models, below).
Default Exposures
107
-------
ChemSTEER User Guide - Updated May 2015
Worker inhalation exposure to the chemical resulting from these activities is calculated using
the EPA/OPPT Mass Balance Inhalation Model.
NOTE: the inhalation exposure model above is only defaulted if the selected operation's
adjusted vapor pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the
Operation Parameters Tab -> Shared Parameters/Factors Subtab topic for more information. If
the operation AVP is outside of the preferred range, there is no model for calculating worker
inhalation exposures during this activity.
Worker dermal exposure to the chemical resulting from these activities is calculated using the
EPA/OPPT 1-Hand Dermal Contact with Liquid Model.
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during the sampling operation is from the evaporation of volatile liquid containing chemical vapor from
open surfaces. You may have information and/or data that better represents the chemical releases
and/or the worker exposures that occur during sampling of liquids. You may select alternative models to
the default models described above to estimate chemical releases and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed >100
feet/min)
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT 2-Hand Dermal Contact with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• EPA/OPPT 2-Hand Dermal Immersion with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
108
-------
ChemSTEER User Guide - Updated May 2015
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Sampling Solids
Definition
The sampling of solid raw material or product that results in a release of the chemical and/or
worker exposure to the chemical.
The following release sources/exposure activities may be selected for operations in which a solid
material containing the chemical is sampled:
• Sampling Solid Raw Material
• Sampling Solid Product
• Sampling Solids
Default Release
No default model exists for releases to the environment from these sources in ChemSTEER.
OPPT assumes that releases from this source are insignificant when compared to other sources. If a
release is expected, you must choose an appropriate model or specify a user-defined release (see Other
Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from these activities is calculated using
the EPA/OPPT Small Volume Solids Handling Inhalation Model.
Worker dermal exposure to the chemical resulting from these activities is calculated using the
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model.
Other Release and Exposure Models
The default exposure models assume that the most significant exposure during the sampling
operation is from handling solid materials containing chemical. You may have information and/or data
that better represents the chemical releases and/or the worker exposures that occur during unloading
of solid raw material from containers. You may select alternative models to the default models
described above to estimate chemical releases and worker exposures.
The following model may be used to estimate releases that occur from this source. More than
one release model may be used at one time to estimate releases, as appropriate.
• User-Defined Loss Rate Model
109
-------
ChemSTEER User Guide - Updated May 2015
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing these activities:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA Total PNOR PEL-Limiting Model
• OSHA Respirable PNOR PEL-Limiting Model
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing these activities
• EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Equipment Cleaning Losses of Liquids
Definition
The cleaning of product residues from one or more process vessels with a liquid cleaning
medium that results in a release of the chemical and/or worker exposure to the chemical.
The following release sources/exposure activities may be selected for operations in which a
liquid washout is performed on process equipment containing chemical:
• Equipment Cleaning Losses from a Single, Small Vessel
• Equipment Cleaning Losses from a Single, Large Vessel
• Equipment Cleaning Losses from Multiple Vessels
Default Releases
Air Release: It is assumed that this activity is performed outdoors (i.e., air speed is >100
feet/min). The amount of chemical release from this source is thus calculated using the EPA/OPPT Mass
Transfer Coefficient Model.
NOTE: the air release model above is only defaulted if the selected operation's adjusted vapor
(AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the Operation Parameters Tab
110
-------
ChemSTEER User Guide - Updated May 2015
Shared Parameters/Factors Subtab topic for more information. If the operation AVP is
outside of the preferred range, there is no model for calculating releases to air from this source.
Non-Air Release: Release of the residual product contained in the single process vessel is
calculated using either the EPA/OPPT Single Vessel Residual Model or EPA/OPPT Multiple Process Vessel
Residual Model, as specified below:
Equipment Cleaning Source
Default Non-Air Release
Equipment Cleaning Losses from a Single, Small Vessel
EPA/OPPT Single Vessel Residual Model
Equipment Cleaning Losses from a Single, Large Vessel
Equipment Cleaning Losses from Multiple Vessels
EPA/OPPT Multiple Process Vessel Residual Model
Default Exposures
No default model exists for worker exposures during this activity in ChemSTEER. OPPT assumes
that equipment cleaning is automated and that exposures during this activity are insignificant when
compared to other activities. If exposures are expected, you must choose an appropriate model or
specify a user-defined exposure (see Other Release and Exposure Models, below).
Other Release and Exposure Models
The default release models assume that the most significant release during the cleaning
operation is from disposal of liquid residues containing the chemical and from the evaporation of
volatile liquid residues containing chemical vapor. You may have information and/or data that better
represents the chemical releases and/or the worker exposures that occur during the cleaning of a single
process vessel. You may select alternative models to the default models described above to estimate
chemical releases and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OPPT Penetration Model (for indoor activities; air speed < 100 feet/min)
• EPA/OAQPS AP-42 Loading Model
• EPA/OPPT Multiple Process Vessel Residual Model (for Equipment Cleaning Losses from
Single, Small Vessel or Equipment Cleaning Losses from Single, Large Vessel)
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
The following inhalation exposure models may be used to estimate the worker exposure that
occurs as a result of performing this activity:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
111
-------
ChemSTEER User Guide - Updated May 2015
The following dermal exposure models may be used to estimate the worker exposure that
occurs as a result of performing this activity:
• EPA/OPPT 1-Hand Dermal Contact with Liquid Model
• EPA/OPPT 2-Hand Dermal Contact with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• EPA/OPPT 2-Hand Dermal Immersion with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Equipment Cleaning Losses of Solids
The following release source/exposure activity may be selected for operations in which a solid
residue containing the chemical is cleaned from process equipment:
• Equipment Cleaning Losses of Solids from Process Vessels
Equipment Cleaning Losses of Solids from Process Vessels
Definition
The cleaning of solid product residues from process vessels that results in a release of the
chemical and/or worker exposure to the chemical.
Default Releases
Release of the residual solid product to non-air media from the process vessels is calculated
using the EPA/OPPT Solid Residuals in Transport Containers Model.
No default model exists for releases to air from this source in ChemSTEER. If a release to air is
expected, you must choose an appropriate model or specify a user-defined release to these media (see
Other Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using one of
the following models:
For continuous operations:
112
-------
ChemSTEER User Guide - Updated May 2015
• If the daily mass of product output (DMOprod) < 54 kg/day, then the EPA/OPPT Small
Volume Solids Handling Inhalation Model is used as a default.
• If the daily mass of product output (DMOprod) > 54 kg/day), then either the OSHA Total
PNOR PEL-Limiting Model or OSHA Respirable PNOR PEL-Limiting Model may be chosen
as a default.
For batch operations:
• If the mass of product output per batch (BMOprod) < 54 kg/batch, then the EPA/OPPT
Small Volume Solids Handling Inhalation Model is used as a default.
• If the mass of product output per batch (BMOprod) >54 kg/batch, then either the OSHA
Total PNOR PEL-Limiting Model or OSHA Respirable PNOR PEL-Limiting Model may be
chosen as a default.
NOTE: If the daily amount of material throughput from the Mass Balance calculations was not
calculated before the inhalation exposure is calculated, the OSHA Total PNOR PEL-Limiting
Model will be used as a default.
EPA Assessment Policy Recommendation: It is recommended that the amount of solid residue
that is cleaned from the vessel or process (i.e., the loss fraction x DMOprod or BMOprod) be
used to select the default inhalation model, instead using the total capacity of the vessel or
process, as described above.
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during the cleaning operation is from disposal of solid residues containing the chemical and from the
generation of dust containing chemical. You may have information and/or data that better represents
the chemical releases and/or the worker exposures that occur during cleaning and disposal of solid
product residues cleaned from process vessels. You may select alternative models to the default models
described above to estimate chemical releases and worker exposures.
The following alternative model may be used to estimate releases that occur from this source.
The model may also be selected in addition to the default, as appropriate.
• User-Defined Loss Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• User-Defined Inhalation Model
113
-------
ChemSTEER User Guide - Updated May 2015
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Unit Operations and Processes
The following release sources/exposure activities may be selected for operations that include
the following processes:
• Aqueous Wash of Organic Mass
• Distillation Column Bottoms Disposal
• Filter Media Changeout
• Grinding and Sanding
• Liquid/Liquid Extraction Solvent Disposal
• Scrubber Releases
Aqueous Wash of Organic Mass
Definition
The aqueous wash of organic material containing the chemical, in which the chemical is
transferred from the organic material into the aqueous phase. The amount of chemical that is
transferred into the aqueous phase is estimated based on its water solubility, by default. This activity
uses default models to estimate the release of the chemical and worker exposure to the chemical.
Default Releases
Release of the chemical to non-air media with the aqueous phase is calculated using the
EPA/OPPT Water Saturation Loss Model.
No default model exists for releases to air from this source in ChemSTEER. OPPT assumes that
releases to air from this source are insignificant when compared to other sources. If a release to air is
expected, you must choose an appropriate model or specify a user-defined release to these media (see
Other Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
User-Defined Inhalation Model.
114
-------
ChemSTEER User Guide - Updated May 2015
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT 2-Hand Dermal Contact with Liquid Model.
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during this operation is from the disposal of an aqueous phase containing the chemical. You may have
information and/or data that better represents the chemical releases and/or the worker exposures that
occur as a result of the aqueous wash of organic material. You may select alternative models to the
default models described above to estimate chemical releases and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OPPT Penetration Model (for indoor activities; air speed < 100 feet/min)
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed >100
feet/min)
• EPA/OAQPS AP-42 Loading Model
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
There are no alternative dermal exposure models available in ChemSTEER at this time.
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Distillation Column Bottoms Disposal
Definition
The disposal of waste collected from distillation column bottoms that contains the chemical and
is estimated to primarily result in the release of the chemical.
Default Releases
Release of the chemical to the environment with the disposal of distillation column bottoms
waste is calculated using the User-Defined Loss Rate Model
115
-------
ChemSTEER User Guide - Updated May 2015
Default Exposures
No default model exists for worker exposures during this activity in ChemSTEER. OPPT assumes
that this activity is closed and automated and that exposures are insignificant when compared to other
activities. If exposures are expected, you must choose an appropriate model or specify a user-defined
exposure (see Other Release and Exposure Models, below).
Other Release and Exposure Models
The default release and exposure models assume that the most significant release during this
activity is from the disposal of a distillation column bottoms containing the chemical. You may have
information and/or data that better represents the chemical releases and/or the worker exposures that
occur as a result of disposing of distillation column bottoms. You may select alternative models to the
default models described above to estimate chemical releases and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OAQPS AP-42 Loading Model
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Filter Media Changeout
Definition
The disposal of waste filter media that contains residual amounts of the chemical and that is
estimated to result in the release of the chemical and worker exposure to the chemical.
116
-------
ChemSTEER User Guide - Updated May 2015
Default Releases
Release of the chemical to the environment with the waste filter media is calculated using the
User-Defined Loss Rate Model
Default Exposures
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model
No default model exists for worker inhalation exposures during this activity in ChemSTEER. If
dermal exposures are expected, you must choose an appropriate model or specify a user-defined
exposure (see Other Release and Exposure Models, below).
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during this operation is from the disposal of wet filter cake material containing the chemical. You may
have information and/or data that better represents the chemical releases and/or the worker exposures
that occur as a result of disposing of waste filter media. You may select alternative models to the default
models described above to estimate chemical releases and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OPPT Penetration Model (for indoor activities; air speed < 100 feet/min)
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed >100
feet/min)
• User-Defined Vapor Generation Rate Model
The following inhalation exposure models may be used to estimate the worker exposure that
occurs as a result of performing this activity:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• EPA/OPPT Small Volume Solids Handling Inhalation Model (for solid amounts <54 kg per
day or per batch)
• OSHA Total PNOR PEL-Limiting Model (for solid amounts >54 kg per day or per batch)
• OSHA Respirable PNOR PEL-Limiting Model (for solid amounts >54 kg per day or per
batch)
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
117
-------
ChemSTEER User Guide - Updated May 2015
• EPA/OPPT 1-Hand Dermal Contact with Liquid Model
• EPA/OPPT 2-Hand Dermal Contact with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• EPA/OPPT 2-Hand Dermal Immersion with Liquid Model
• EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Grinding and Sanding
Definition
The grinding or sanding of a solid material that contains the chemical and that is estimated to
result in the release of the chemical and worker exposure to the chemical.
Default Releases
Release of the chemical to the environment as a result of grinding/sanding activities is
calculated using the User-Defined Loss Rate Model.
Default Exposures
This activity is assumed to generate >54 kg of particulates per day, and thus the worker
inhalation exposure to the chemical resulting from this activity is calculated using either the OSHA Total
PNOR PEL-Limiting Model.
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during this operation is from the generation of dusts containing the chemical. You may have information
and/or data that better represents the chemical releases and/or the worker exposures that occur as a
result of grinding and/or sanding activities. You may select alternative models to the default models
described above to estimate chemical releases and worker exposures.
At this time, ChemSTEER does not contain other release models that are appropriate for this
activity.
118
-------
ChemSTEER User Guide - Updated May 2015
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA Respirable PNOR PEL-Limiting Model
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker exposure
that occurs as a result of performing this activity:
• EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Liquid/Liquid Extraction Solvent Disposal
Definition
The disposal of waste solvent containing the chemical that is collected from a liquid-liquid
extraction process and is estimated to result in the release of the chemical and worker exposure to the
chemical.
Default Releases
Release of the chemical to the environment with the waste solvent is calculated using the User-
Defined Loss Rate Model.
Default Exposures
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT 2-Hand Dermal Contact with Liquid Model.
No default model exists for worker inhalation exposures during this activity in ChemSTEER. You
must choose an appropriate model or specify a user-defined exposure (see Other Release and Exposure
Models, below).
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during this operation is from the disposal of solvent material containing the chemical. You may have
119
-------
ChemSTEER User Guide - Updated May 2015
information and/or data that better represents the chemical releases and/or the worker exposures that
occur as a result of disposing of distillation column bottoms. You may select alternative models to the
default models described above to estimate chemical releases and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OPPT Penetration Model (for indoor activities; air speed < 100 feet/min)
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed >100
feet/min)
• EPA/OAQPS AP-42 Loading Model
• User-Defined Vapor Generation Rate Model
The following inhalation exposure models may be appropriate alternatives for calculating
worker exposure that occurs as a result of performing this activity:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
There are no alternative dermal exposure models available in ChemSTEER at this time.
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Scrubber Releases
Definition
The release of the chemical from a process scrubber device that is also estimated to result in
worker exposure to the chemical.
Default Releases
Release of the chemical to the environment from the scrubber device is calculated using the
User-Defined Loss Rate Model.
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
User-Defined Inhalation Model.
120
-------
ChemSTEER User Guide - Updated May 2015
No default model exists for worker dermal exposures during this activity in ChemSTEER. If
dermal exposures are expected, you must choose an appropriate model or specify a user-defined
exposure (see Other Release and Exposure Models, below).
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during this operation is from the release and/or disposal of waste materials containing the chemical
from a scrubber device. You may have information and/or data that better represents the chemical
releases and/or the worker exposures that occur as a result of the releases from a scrubber device. You
may select alternative models to the default models described above to estimate chemical releases and
worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OPPT Penetration Model (for indoor activities; air speed < 100 feet/min)
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed >100
feet/min)
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
There are no alternative dermal exposure models available in ChemSTEER at this time.
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Vapor Release from Transfer Operations
The following release source/exposure activity may be selected for operations in which the
chemical is volatilized and released from a liquid pool or other type of open liquid surface:
• Vapor Releases from Open Liquid Surfaces
Vapor Releases from Open Liquid Surfaces
Definition
121
-------
ChemSTEER User Guide - Updated May 2015
The release of chemical vapors as a result of a pool of volatile liquid or other liquid surface that
is open to the environment. There may also be a potential for worker inhalation exposures to the
chemical vapors.
Default Release
Release of the chemical to air is calculated using the User-Defined Vapor Generation Rate Model
as a default.
NOTE: the air release model above is only defaulted if the selected operation's adjusted vapor
pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the Operation
Parameters Tab -> Shared Parameters/Factors Subtab topic for more information. If the
operation AVP is outside of the preferred range, there is no model for calculating releases to air
from this source.
No default model exists for releases to non-air media from this source in ChemSTEER. OPPT
assumes that releases from this source are insignificant when compared to other sources. If a release is
expected, you must choose an appropriate model or specify a user-defined release to these media (see
Other Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Mass Balance Inhalation Model.
NOTE: In order to utilize the above vapor inhalation model, you must select and run a vapor
generation release model for this source/activity in order to obtain the necessary input
parameters for this model.
NOTE: the inhalation exposure model above is only defaulted if the selected operation's
adjusted vapor pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the
Operation Parameters Tab -> Shared Parameters/Factors Subtab topic for more information. If
the operation AVP is outside of the preferred range, there is no model for calculating worker
inhalation exposures during this activity.
No default model exists for worker dermal exposures during this activity in ChemSTEER. If
dermal exposures are expected, you must choose an appropriate model or specify a user-defined
exposure (see Other Release and Exposure Models, below).
Other Release and Exposure Models
The default release and exposure models assume that the most significant exposure during this
operation is from the evaporation of volatile liquid containing chemical vapor from an open surface. You
may have information and/or data that better represents the chemical releases and/or the worker
exposures that occur during the release of chemical vapor during open transfer operations. You may
select alternative models to the default models described above to estimate chemical releases and
worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
122
-------
ChemSTEER User Guide - Updated May 2015
• EPA/OPPT Penetration Model (for indoor activities; air speed < 100 feet/min)
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed > 100
feet/min)
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following dermal exposure model may be used to estimate the worker exposure that occurs
as a result of performing this activity:
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Miscellaneous Sources/Activities
The following may be selected for operations that include either sources of release or worker
activities resulting in exposures that you wish to define:
• Miscellaneous Sources/Activities Related to Liquid Processing
• Miscellaneous Sources/Activities Related to Solid Processing
Miscellaneous Sources/Activities Related to Liquid Processing
Definition
A source of release and/or a worker activity involving a liquid containing the chemical that
results in the release of the chemical and/or worker exposure to the chemical. This source/activity may
be used in the absence of a more suitable choice in ChemSTEER.
Default Release
No default model exists for releases to the environment from this source in ChemSTEER. If a
release is expected, you must choose an appropriate model or specify a user-defined release (see Other
Release and Exposure Models, below).
123
-------
ChemSTEER User Guide - Updated May 2015
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
User-Defined Inhalation Model.
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT 1-Hand Dermal Contact with Liquid Model.
Other Release and Exposure Models
The default exposure models assume that the most significant exposure during this operation is
handling a liquid material containing the chemical. You may have information and/or data that better
represents the chemical releases and/or the worker exposures that occur during the activity. You may
select alternative models to the default models described above to estimate chemical releases and
worker exposures.
The following models may be used to estimate releases that occur from this source. More than
one release model may be used at one time to estimate releases, as appropriate.
• EPA/OPPT Penetration ModeKfor indoor activities; air speed < 100 feet/min)
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed >100
feet/min)
• EPA/OAQPS AP-42 Loading Model
• EPA/OPPT Water Saturation Loss Model
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA Total PNOR PEL-Limiting Model
• OSHA Respirable PNOR PEL-Limiting Model
• EPA/OPPT UV Roll Coating Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT 1-Hand Dermal Contact with Liquid Model
• EPA/OPPT 2-Hand Dermal Contact with Liquid Model
124
-------
ChemSTEER User Guide - Updated May 2015
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Miscellaneous Sources/Activities Related to Solid Processing
Definition
A source of release and/or a worker activity involving a solid/particulate containing the chemical
that results in the release of the chemical and/or worker exposure to the chemical. This source/activity
may be used in the absence of a more suitable choice in ChemSTEER.
Default Release
No default model exists for releases to the environment from this source in ChemSTEER. If a
release is expected, you must choose an appropriate model or specify a user-defined release (see Other
Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using one of
the following models:
For continuous operations:
• If the daily mass of product output (DMOprod) < 54 kg/day, then the EPA/OPPT Small
Volume Solids Handling Inhalation Model is used as a default.
• If the daily mass of product output (DMOprod) > 54 kg/day), then either the OSHA Total
PNOR PEL-Limiting Model or OSHA Respirable PNOR PEL-Limiting Model may be chosen
as a default.
For batch operations:
• If the mass of product output per batch (BMOprod) < 54 kg/batch, then the EPA/OPPT
Small Volume Solids Handling Inhalation Model is used as a default.
• If the mass of product output per batch (BMOprod) >54 kg/batch, then either the OSHA
Total PNOR PEL-Limiting Model or OSHA Respirable PNOR PEL-Limiting Model may be
chosen as a default.
NOTE: If the daily amount of material throughput from the Mass Balance calculations was not
calculated by ChemSTEER before the inhalation exposure is calculated, the OSHA Total PNOR
PEL-Limiting Model will be used as a default.
125
-------
ChemSTEER User Guide - Updated May 2015
Worker dermal exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model
Other Release and Exposure Models
The default exposure models assume that the most significant exposure during this operation is
handling a solid material containing the chemical. You may have information and/or data that better
represents the chemical releases and/or the worker exposures that occur during the activity. You may
select alternative models to the default models described above to estimate chemical releases and
worker exposures.
The following models may be used to estimate releases that occur from this source. More than
one release model may be used at one time to estimate releases, as appropriate.
• EPA/OPPT Water Saturation Loss Model
• User-Defined Loss Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• EPA/OPPT UV Roll Coating Inhalation Model
• User-Defined Inhalation Model
The following alternative dermal exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Automobile Spray Coating
The following release source/exposure activity may be selected for operations in which a liquid
coating material containing the chemical is sprayed onto automobile surfaces:
• Automobile OEM Spray Coating Application
• Automobile Refinish Spray Coating Application
126
-------
ChemSTEER User Guide - Updated May 2015
Automobile OEM Spray Coating Application
Definition
The spraying of a liquid coating material onto an automobile surface with a spray gun and within
a spray booth with mist capture controls that results in a release of the chemical and/or worker
exposure to the chemical.
Default Releases
Multi-media Release: The amount of chemical released to both air and non-air media as a result
of oversprayed mists generated by this activity is calculated using the EPA/OPPT Automobile OEM
Coating Oversprav Loss Model. This model apportions amounts of the oversprayed mist that is collected
by the spraybooth and control technology, as well as the amount of mist that is emitted from the booth
to air.
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Automobile OEM Spray Coating Inhalation Exposure Model.
Worker dermal exposure to the chemical resulting from this activity is calculated using the US
EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
EPA/OPPT 2-Hand Dermal Immersion with Liquid Model.
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during the automobile spray coating operation is from the generation of coating mists as a result of
overspray (or "bounce-back"). You may have information and/or data that better represents the
chemical releases and/or the worker exposures that occur during the spray coating of automobiles. You
may select alternative models to the default models described above to estimate chemical releases and
worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
• EPA/OPPT Automobile Refinish Coating Oversprav Loss Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA PEL-Limiting Model for Substance-Specific Vapors
127
-------
ChemSTEER User Guide - Updated May 2015
• User-Defined Inhalation Model
• EPA/OPPT Automobile Refinish Spray Coating Inhalation Exposure Model
• EPA/OPPT Automobile Spray Coating Inhalation Exposure Model (non-volatile
polyisocyanates)
The following alternative dermal exposure model may be used to estimate the worker exposure
that occurs as a result of performing this activity:
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Automobile Refinish Spray Coating Application
Definition
The spraying of a liquid coating material onto an automobile surface with a spray gun and within
a spray booth with mist capture controls that results in a release of the chemical and/or worker
exposure to the chemical.
Default Releases
Multi-media Release: The amount of chemical released to both air and non-air media as a result
of oversprayed mists generated by this activity is calculated using the EPA/OPPT Automobile Refinish
Coating Overspray Loss Model. This model apportions amounts of the oversprayed mist that is collected
by the spraybooth and control technology, as well as the amount of mist that is emitted from the booth
to air.
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT Automobile Refinish Spray Coating Inhalation Exposure Model.
Worker dermal exposure to the chemical resulting from this activity is calculated using the US
EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
EPA/OPPT 2-Hand Dermal Immersion with Liquid Model.
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during the automobile spray coating operation is from the generation of coating mists as a result of
overspray (or "bounce-back"). You may have information and/or data that better represents the
128
-------
ChemSTEER User Guide - Updated May 2015
chemical releases and/or the worker exposures that occur during the spray coating of automobiles. You
may select alternative models to the default models described above to estimate chemical releases and
worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
• EPA/OPPT Automobile OEM Coating Overspray Loss Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
• EPA/OPPT Automobile OEM Spray Coating Inhalation Exposure Model
• EPA/OPPT Automobile Spray Coating Inhalation Exposure Model (non-volatile
polyisocyanates)
The following alternative dermal exposure model may be used to estimate the worker exposure
that occurs as a result of performing this activity:
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Generic Coating Applications
The following release sources/exposure activities may be selected for operations in which a
liquid coating material containing the chemical is applied to a substrate surface:
• Roll Coating
• Coating Using Hand Held Spray Gun
• Coating Using Hand Held Spray Can
Roll Coating
129
-------
ChemSTEER User Guide - Updated May 2015
Definition
The application of a liquid coating material onto a surface or substrate via machine or hand
rolling technique that results in a release of the chemical and/or worker exposure to the chemical.
Default Releases
Release of the chemical to the environment from roll coating activity is calculated using the
User-Defined Loss Rate Model.
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
EPA/OPPT UV Roll Coating Inhalation Model.
No default model exists for worker dermal exposures during this activity in ChemSTEER. If
dermal exposures are expected, you must choose an appropriate model or specify a user-defined
exposure (see Other Release and Exposure Models, below).
Other Release and Exposure Models
The default release and exposure models assume that the most significant release and exposure
during the roll coating operation is from the generation of coating mists from the moving roller(s). You
may have information and/or data that better represents the chemical releases and/or the worker
exposures that occur during the spray coating of automobiles. You may select alternative models to the
default models described above to estimate chemical releases and worker exposures.
The following alternative models may be used to estimate releases that occur from this source.
These models may also be selected in addition to the default, as appropriate.
• EPA/OPPT Penetration Model (for indoor activities; air speed < 100 feet/min)
• EPA/OPPT Mass Transfer Coefficient Model (for outdoor activities; air speed >100
feet/min)
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• OSHA Total PNOR PEL-Limiting Model
• OSHA Respirable PNOR PEL-Limiting Model
• User-Defined Inhalation Model
130
-------
ChemSTEER User Guide - Updated May 2015
The following dermal exposure models may be used to estimate the worker exposure that
occurs as a result of performing this activity:
• EPA/OPPT 2-Hand Dermal Contact with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Coating Using Hand Held Spray Gun
Definition
The manual spraying of a liquid coating material onto a surface using a spray gun that results in
a release of the chemical and/or worker exposure to the chemical.
Default Releases
No default model exists for releases to the environment from this source in ChemSTEER. If a
release is expected, you must choose an appropriate model or specify a user-defined release (see Other
Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
OSHA Total PNOR PEL-Limiting Model.
No default model exists for worker dermal exposures during this activity in ChemSTEER. If
dermal exposures are expected, you must choose an appropriate model or specify a user-defined
exposure (see Other Release and Exposure Models, below).
Other Release and Exposure Models
The default exposure model assumes that the most significant exposure during manual spraying
is from inhalation of the oversprayed mists. You may have information and/or data that better
represents the chemical releases and/or the worker exposures that occur during the spray coating
activity. You may select alternative models to the default models described above to estimate chemical
releases and worker exposures.
The following models may be used to estimate releases that occur from this source. More than
one release model may be used at one time to estimate releases, as appropriate.
• EPA/OPPT Automobile Refinish Coating Overspray Loss Model
• User-Defined Loss Rate Model
131
-------
ChemSTEER User Guide - Updated May 2015
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following dermal exposure models may be used to estimate the worker exposure that
occurs as a result of performing this activity:
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• EPA/OPPT 2-Hand Dermal Immersion with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Coating Using Hand Held Spray Can
Definition
The manual spraying of a liquid coating material onto a surface using a spray can that results in a
release of the chemical and/or worker exposure to the chemical.
Default Releases
No default model exists for releases to the environment from this source in ChemSTEER. If a
release is expected, you must choose an appropriate model or specify a user-defined release (see Other
Release and Exposure Models, below).
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
User-Defined Inhalation Model.
No default model exists for worker dermal exposures during this activity in ChemSTEER. If
dermal exposures are expected, you must choose an appropriate model or specify a user-defined
exposure (see Other Release and Exposure Models, below).
Other Release and Exposure Models
132
-------
ChemSTEER User Guide - Updated May 2015
The default exposure model assumes that the most significant exposure during manual spraying
is from inhalation of the oversprayed mists. You may have information and/or data that better
represents the chemical releases and/or the worker exposures that occur during the spray coating
activity. You may select alternative models to the default models described above to estimate chemical
releases and worker exposures.
The following models may be used to estimate releases that occur from this source. More than
one release model may be used at one time to estimate releases, as appropriate.
• EPA/OPPT Automobile Refinish Coating Overspray Loss Model
• User-Defined Loss Rate Model
• User-Defined Vapor Generation Rate Model
The following alternative inhalation exposure models may be used to estimate the worker
exposure that occurs as a result of performing this activity:
• OSHA Total PNOR PEL-Limiting Model
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following dermal exposure models may be used to estimate the worker exposure that
occurs as a result of performing this activity:
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• EPA/OPPT 2-Hand Dermal Immersion with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Electroplating Bath Additives
The following release sources/activities may be selected for operations in which an additive is
used within an electroplating bath/solution:
• Operating the Electroplating Bath
133
-------
ChemSTEER User Guide - Updated May 2015
• Rinsing Electroplated Parts
• Changing Electroplating Bath
Operating the Electroplating Bath
Definition
The use of an additive (containing the chemical being assessed) in electroplating baths/solutions
that results in a dermal exposure to the workers who operate the bath (releases of the chemical are not
expected during the electroplating process).
Default Releases
No default model exists for releases to the environment from this source in ChemSTEER. If a
release is expected, you must choose an appropriate model or specify a user-defined release.
Default Exposures
Worker inhalation exposure to the chemical resulting from this activity is calculated using the
OSHA PEL-Limiting Model for Substance-Specific Particulates. In this activity, the model uses the OSHA
PEL for chromium (KCk = 0.5 mg/m3) and an estimated chromium concentration in an electroplating
bath (Ypel=0.25) as overriding defaults to this model's standard default values.
No default model exists for worker dermal exposures during this activity in ChemSTEER. If a
dermal exposure is expected, you must choose an appropriate model or specify a user-defined
exposure.
Other Release and Exposure Models
You may have information and/or data that support the potential for an environmental release
of the chemical during the electroplating process. You may select models to estimate the release. You
are encouraged to review the calculations and bases of ChemSTEER's release models (see Quick
Summary of ChemSTEER Release Models) prior to using within this source/activity.
You may also have information and/or data that support the potential for worker dermal
exposures (or alternative inhalation exposures) during the electroplating process. You may select
models to estimate worker inhalation and/or dermal exposures. You are encouraged to review the
calculations and bases of ChemSTEER's exposure models (see General Guidelines for Exposure
Assessment) prior to using within this source/activity.
Important Note: this source/activity was designed for use within the Electroplating Bath
Additive Use operation to use the above described default model. It is recommended that you
do NOT alter the default release model selections for this source/activity. If you wish to
calculate additional releases from this operation (e.g., empty container residues), you should
select the appropriate sources/activities and their associated release/exposure models in
addition to the Operating the Electroplating Bath activity and the other default sources for this
operation. You are encouraged to review the bases and default models used by the other
sources/activities (see Operations Tab -> Sources/Activities Subtab) prior to selecting other
sources/activities for this operation.
134
-------
ChemSTEER User Guide - Updated May 2015
The Changing Electroplating Bath source/activity can NOT be used within any other operation
than the Electroplating Bath Additive Use operation.
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Rinsing Electroplated Parts
Definition
The use of an additive (containing the chemical being assessed) in electroplating baths/solutions
that results in a release of the chemical (worker exposures are not expected after the chemical is added
to the bath).
Default Releases
Multi-media Release: The amount of chemical released to both water and land or incineration as
a result of rinsing the chemical from electroplated parts surfaces is calculated using the EPA/OPPT
Electroplating Rinse Water Loss Model. This model apportions amounts of chemical in the rinsate that
are removed from the process wastewater by the treatment system and disposed with the sludge, as
well as the amount of chemical that is discharged to water with the final effluent.
Default Exposures
No default model exists for worker exposures during this activity in ChemSTEER. OPPT assumes
that workers do not come into contact with the additive while it is rinsed from electroplated parts. If
exposures are expected, you must choose an appropriate model or specify a user-defined exposure.
Other Release and Exposure Models
You may have information and/or data that support the potential for worker exposures during
the rinsing of the electroplated part. You may select models to estimate worker exposures. You are
encouraged to review the calculations and bases of ChemSTEER's exposure models (see General
Guidelines for Release Assessment) prior to using within this source/activity.
Important Note: this source/activity was designed for use within the Electroplating Bath
Additive Use operation to use the above described default model. It is recommended that you
do NOT alter the default release model selections for this source/activity. If you wish to
calculate additional releases from this operation (e.g., empty container residues), you should
select the appropriate sources/activities and their associated release/exposure models in
addition to the Rinsing Electroplated Parts source and the other default sources/activities for
this operation. You are encouraged to review the bases and default models used by the other
sources/activities (see Operations Tab Sources/Activities Subtab) prior to selecting other
sources/activities for this operation.
135
-------
ChemSTEER User Guide - Updated May 2015
The Rinsing Electroplated Parts source/activity can NOT be used within any other operation than
the Electroplating Bath Additive Use operation.
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Changing Electroplating Bath
Definition
The use of an additive (containing the chemical being assessed) in electroplating baths/solutions
that results in a release of the chemical (worker exposures are not expected after the chemical is added
to the bath).
Default Releases
Multi-media Release: The amount of chemical released to both water and land or incineration as
a result of changing the electroplating bath solution is calculated using the EPA/OPPT Electroplating
Spent Bath Disposal Model. This model apportions amounts of chemical in the spent bath that are
removed by the treatment system and disposed with the sludge, as well as the amount of chemical that
is discharged to water with the final effluent.
Default Exposures
No default model exists for worker exposures during this activity in ChemSTEER. OPPT assumes
that workers do not come into contact with the additive during the spent bath wastewater treatment or
discharge. If exposures are expected, you must choose an appropriate model or specify a user-defined
exposure.
Other Release and Exposure Models
You may have information and/or data that support the potential for worker exposures during
the treatment and discharge of the electroplating additive. You may select models to estimate worker
exposures. You are encouraged to review the calculations and bases of ChemSTEER's exposure models
(see General Guidelines for Exposure Assessment) prior to using within this source/activity.
Important Note: this source/activity was designed for use within the Electroplating Bath
Additive Use operation to use the above described default model. It is recommended that you
do NOT alter the default release model selections for this source/activity. If you wish to
calculate additional releases from this operation (e.g., empty container residues), you should
select the appropriate sources/activities and their associated release/exposure models in
addition to the Rinsing Electroplated Parts source and the other default sources/activities for
this operation. You are encouraged to review the bases and default models used by the other
sources/activities (see Operations Tab Sources/Activities Subtab) prior to selecting other
sources/activities for this operation.
136
-------
ChemSTEER User Guide - Updated May 2015
The Changing Electroplating Bath source/activity can NOT be used within any other operation
than the Electroplating Bath Additive Use operation.
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
Recirculating Water-Cooling Tower Additives
The following release source may be selected for operations in which an additive is used within
recirculating water-cooling towers:
• Recirculating Water-Cooling Tower Additive Releases
Recirculating Water-Cooling Tower Additive Releases
Definition
The use of an additive (containing the chemical being assessed) to recirculating water-cooling
tower systems that results in a release of the chemical (worker exposures are not expected after the
chemical is added to the system).
Default Releases
Air Release:
Release of the chemical contained in the additive as a result of windage losses of the
recirculating fluid (e.g., water) mists is calculated using the EPA/OPPT Cooling Tower Windage Loss
Model.
Release of the chemical (if volatile) as a result of the evaporation of the recirculating fluid is
calculated using the EPA/OPPT Cooling Tower Evaporative Loss Model (volatiles).
NOTE: the air release model above is only defaulted if the selected operation's adjusted vapor
pressure (AVPrm, AVPprod) is within the preferred range of AVPs. Refer to the Operation
Parameters Tab Shared Parameters/Factors Subtab topic for more information. If the
operation AVP is outside of the preferred range, there is no model for calculating releases to air
from this source.
Water Release:
Release of the chemical contained in the additive as a result of the periodic blowdown of the
recirculating fluid is calculated using the EPA/OPPT Cooling Tower Blowdown Loss Model.
Default Exposures
No default model exists for worker exposures during this activity in ChemSTEER. OPPT assumes
that once the additive enters the recirculating water-cooling tower system, workers do not come into
contact with the additive during its use or release. If exposures are expected, you must choose an
appropriate model or specify a user-defined exposure.
137
-------
ChemSTEER User Guide - Updated May 2015
Other Release and Exposure Models
You may have information and/or data that support the potential for worker exposures during
the use of the water-cooling tower additive. You may select models to estimate worker exposures. You
are encouraged to review the calculations and bases of ChemSTEER's exposure models (see General
Guidelines for Exposure Assessment) prior to using within this source/activity.
Important Note: this source/activity was designed for use within the Recirculating Water-
Cooling Tower Additive Use Operation to use the above described default models. It is
recommended that you do NOT alter the default release model selections for this
source/activity. If you wish to calculate additional releases from this operation (e.g., empty
container residues), you should select the appropriate sources/activities and their associated
release/exposure models in addition to the Recirculating Water-Cooling Tower Additive Releases
source. You are encouraged to review the bases and default models used by the other
sources/activities (see Operations Tab Sources/Activities Subtab) prior to selecting other
sources/activities for this operation.
The Recirculating Water-Cooling Tower Additive Releases source/activity can NOT be used
within any other operation than the Recirculating Water-Cooling Tower Additive Use operation.
Note to the user: ChemSTEER currently allows you to select ANY release or exposure model
contained in the software to calculate release amounts and worker exposures. Be aware that
not all of the models contained in the software are appropriate for a particular source/activity.
Please refer to this topic when choosing an appropriate alternative release/exposure model.
138
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER Estimation Methods and Models
The environmental release models are accessed on the Estimating Chemical Releases Tab and
the inhalation and dermal exposure models are accessed on the Estimating Chemical Exposures Tab.
You must have selected at least one operation with at least one source/activity (see Operations
Tab Sources/Activities Subtab section) in your assessment in order to run any of the release or
exposure models. You are also required to provide any input parameter values that are required by the
model and for which ChemSTEER does not have a default value.
Complete documentation for each of the environmental release and worker exposure models is
located in pages of this User Guide section. Each of the model topics describes type of release or
exposure that the model calculates, default target environmental media or route of exposure, and the
form of the chemical. Definitions, all equations and input parameters, descriptions of all default values
and associated logic behind conditional defaults, as well as any non-default options for each of the input
parameters are also provided.
The methods and models used in ChemSTEER are from several EPA sources, including the
"Chemical Engineering Branch Manual for the Preparation of Engineering Assessments" and other
reports and memoranda detailing the methods used in CEB assessments. References to the industry-
specific operations are taken from the "Chemical Engineering Branch Compilation of Generic Scenarios
for Chemical Uses." These references document the various empirical, mathematical, and suppositional
methods and models that have been developed and used by EPA over many years of workplace
exposure and release assessment.
To review a complete list of references used in ChemSTEER, go to the References section of this
User Guide.
The environmental release model topics are organized by target environmental media (air, non-
air, and multi-media), as well as by the form of the chemical when released (vapor, liquid, solid) and
associated mechanism of release (evaporation, residual and waste).
The worker exposure model topics are organized by route of exposure (inhalation and dermal),
form of the chemical during the activity (liquid, solid) and mechanism (evaporation, vapor displacement,
misting, dusting, and dermal contact with the chemical or surfaces). There is also a section that contains
the set of exposure models based on exposure limits.
General Information on Model Parameters
Changing Default Values
You may elect to change any model parameter to an alternative value to the default. To do this,
click on the Type column for the parameter. For most parameters you have two choices:
• ChemSTEER defaults for that model; and
• User-defined.
139
-------
ChemSTEER User Guide - Updated May 2015
Some model parameters have more than these two options for designating input values. In
addition, some model parameters (i.e., those that are generated by another model) cannot be changed.
These parameters are designated with 'Model Output' in the Type column.
Be sure to read the specific model documentation topic in this User Guide for a complete
description of each parameter's non-default options.
Note About Frequency of Release (Freq) Values
If you select a non-default Freq or enter a User-defined Freq with a value greater than 365,
ChemSTEER will display a pop-up message warning you that the choice is invalid because it exceeds 365
days/yr. You must then choose an option that will result in Freq < 365 days/yr before ChemSTEER will
allow you move on from the selection process.
Note About Exposure Days per Year (ED) Values
If you select a non-default ED or enter a User-defined ED with a value greater than 365,
ChemSTEER will display a pop-up message warning you that the choice is invalid because it exceeds 365
days/yr. You must then choose an option that will result in ED < 365 days/yr before ChemSTEER will
allow you move on from the selection process.
The Parameter Type Column
ChemSTEER will indicate whether the parameter used is the ChemSTEER default or a user-
selected non-default parameter in the Parameter Type Column.
The Value Calc Column
In the Value Calc column, ChemSTEER displays the equation or parameter origin (tab location)
that was used to generate the value used in the model equation.
Running the Model
After you have updated the model parameters and click the Run Model button, ChemSTEER
updates all of the model results for the selected operation. If the total annual release (AR) is greater
than the operation's total production volume (PVop), ChemSTEER will display a pop-up message warning
you that the annual release for this model exceeds the volume estimated for this operation; however
ChemSTEER will allow you to continue.
Calculating Two Sets of Results from a Single Model
This function is designed to allow you to perform concurrent calculations of two model results
from two sets of input parameters. These sets of input parameters and outputs are generally labeled
Output 1 and Output 2; however, you can characterize the results by selecting from a pick-list of choices
or by entering a short description of your own. For example, this feature can be used to calculate a
range of model results using a range in at least one input parameter value.
Model Input Parameter Columns and On/Off Switches
140
-------
ChemSTEER User Guide - Updated May 2015
Each model input parameter has a Units, Type, Origin, and Value column.
For the release model input parameters, these are displayed in both the Releases tab - Release
Input Parameters subtab and the View/Update Release Model Information screen.
Likewise, for the exposure model input parameters, these are displayed on the Exposures tab -
(Dermal or Inhalation) Model Input Parameters subtabs and the View/Update Exposure Model
Information screen.
In the View/Update (Release or Exposure) Model Information screens, there are two check boxes
(Enable Model Parameters for Output 1 and Enable Model Parameters for Output 2) that allow you to
turn on/off each of two sets of parameter values. By checking each of the boxes, the associated set of
parameter columns will be displayed in the View/Update (Release or Exposure) Model Information
screens; the Releases tab - Release Input Parameters subtab; and the Exposures tab - (Dermal or
Inhalation) Model Input Parameters subtabs. When both boxes are checked, both sets of parameter
values will be used by the selected release or exposure model (as applicable) and will cause two results
to be calculated by the model.
Each set of input parameters will be displayed in the appropriate columns. For example, input
parameters for Output 1 will appear in columns labeled Type - Output 1, Origin - Output 1, and Value -
Output 1. Likewise, the input parameters for Output 2 will appear in columns labeled Type - Output 2,
Origin - Output 2, and Value - Output 2.
NOTE: each of the release models selected in the assessment will have a separate Output
1/Output 2 setting. In other words, some models will be run for one output as a default, while others
are run for both outputs. Each of the User Guide topics for the release/exposure models describe the
particular input parameter default values for Output 1 and/or Output 2. These topics also state which of
the sets of parameters is enabled by default. Where there is only one default value for an input
parameter, the default will be the same for Output 1 and Output 2.
You may enable/disable either one of the model parameter sets by toggling the check boxes. If
you disable one of the sets of parameter values, those values will not be displayed on the Releases or
Exposures tab screens, as appropriate; however, ChemSTEER will retain that set of input parameter
values such that if the box is enabled again in the assessment, the set of values can be recalled.
For example, you can enable both boxes, enter several Output 2 parameter values, run the
model, and print a report showing both model output values. Later, you want to generate a report of a
more conservative (i.e., higher) model output values, designated as Output 1. You would disable the
Output 2 parameter values, run the model and subsequently, the report. Again, at a future time, you
wish to call up the assessment again to use as a basis for a similar new assessment. You will be able to
re-enable the Output 2 values to view them and/or reprint the report.
You may also disable both outputs, for example if you wish to temporarily exclude a release
source from an operation's combined releases.
Default Parameter Values
141
-------
ChemSTEER User Guide - Updated May 2015
As a general default, both Output 1 and Output 2 values for a single parameter are equivalent
(unless a particular model contains two accepted default values). If you enable the Output 2 parameters
(by clicking on the check box), you may enter a new value (if the parameter allows for user-specified
values) or select from the set of appropriate non-default options; however, ChemSTEER will allow any
and all input parameters for Output 1 and Output 2 to be equivalent.
Some model parameter values are based on inputs entered on other tabs (e.g., MW from the
Chemical tab; and NSfrom the Mass Balance Parameters subtab of the Operation Parameters tab).
These parameter values will default to the value entered in the other ChemSTEER screens, as described
in each model's User Guide topic, regardless of which of the Output 1/Output 2 parameter sets are
enabled. If both of the Enable Model Parameters for Output 1/Output 2 boxes are checked, both of the
parameter values will be equivalent by default. For example, the chemical's molecular weight (MW)
from the Chemical tab will be used as the default for both the Output 1 and the Output 2 in the Releases
or Exposures tab in this case. You may then elect to change one or both parameter values at the model
level, preserving the value entered in the originating ChemSTEER screen.
In cases where an exposure model obtains default values from those used or generated by an
associated release model, the input parameters for the exposure model Output 1 will be obtained from
those values used for the associated release model Output 1; and the input parameters for the exposure
model Output 2 will be obtained from those values used for the associated release model Output 2. If
you ran the associated release model with either Output 1 or Output 2 disabled, some of the model-
generated parameters may not be available for the associated exposure model inputs. For example, if
you run the AP-42 Loading Model only for Output 1 (i.e., Output 2 is disabled) and then attempt to run
the Mass Balance Inhalation Model for both Output 1 and Output 2, the value for G for Output 2 will be
zero.
When ChemSTEER finds that an input parameter has not been specified or calculated, a message
is displayed that specifies which input parameter needs to be calculated or entered in order to run the
release or exposure model. This message also specifies for which output (i.e., Output 1 or Output 2) the
input parameter is required.
Model Result Characterization Selection/Entry
There are two combo boxes located in the View/Update (Release and Exposure) Model
Information screens: Characterization of Output 1 Results, and Characterization of Output 2 Results.
These allow you to characterize the model results by either selecting a descriptor from a list, or entering
your own characterization descriptor. These labels can also be used to further document the
ChemSTEER release and exposure model results within the software.
In a future version of ChemSTEER, when you will have the ability to customize your release and
exposure combinations, these individual model result characterizations may be exported into the IRER
or other future ChemSTEER reports.
The following is the list of characterization descriptors for each of these combo boxes:
• Output 1 (default for Output 1, unless otherwise defaulted by the model)
• Low End of Range
142
-------
ChemSTEER User Guide - Updated May 2015
• Average
• Median
• Central Tendency
• Typical
• High End of Range
• High End
• Conservative
• Bounding
• Maximum Based on Limit of Detection
• Worst Case
• What-lf
• User-Input (if this option is selected, the combo box will allow the user to key in their
own descriptor (up to 25 characters)).
NOTE: for some release and exposure models, an alternative default characterization descriptor
may be specified based on the characterization of the default model input parameter values. Please
refer to the individual model User Guide topic descriptions for any overriding defaults to the generic
setting described above.
The current settings for each of these characterizations is displayed with the model results in
the Estimated Releases and Activity Exposure Estimates subtabs
It is important for you to be consistent in how you enter the alternate input values for Output 1
and Output 2 and to be aware that the characterizations chosen or entered (as described above) are for
the model results. The Output 1 parameters provide for the Output 1 model result and the Output 2
parameters provide for the Output 2 model result. For example, if you wish to calculate a range in model
results based on a range in input data, you could characterize Output 1 results as "Low End of Range"
and Output 2 results as "High End of Range". What is important to note is that the Output 1 input
parameter values will not necessarily be less than the Output 2 parameter values. In other words, if the
parameter is inversely related to the model result (e.g., it is a denominator in the equation), the Output
1 = Low End of Range model parameter value will be greater than the Output 2 = High End of Range
model parameter value (i.e., the greater denominator value, the lower the calculation result value).
Release Model Results
Each calculated release result is displayed in the following seven columns on the Releases tab -
Estimated Releases subtab:
• Media;
• Characterization of Results;
• Number of Sites;
143
-------
ChemSTEER User Guide - Updated May 2015
• Days of Release;
• Daily Release Rate;
• Annual Release Rate; and
• Basis.
The Characterization of Results column contains the characterization settings for each of the
output sets (i.e., Output 1 and Output 2) for each receiving environmental medium.
Based on the enable/disable status of the Enable Model Parameters for Output 1 and Enable
Model Parameters for Output 2 boxes in the View/Update Release Model Information screen when the
Run Model(s) button is clicked, the appropriate set(s) of release results are displayed in the Estimated
Releases subtab in one or two rows for each media of release.
The values displayed in the columns are derived by running the model calculation. When the
Run Model(s) button is clicked, the model will perform two calculations (i.e., one for Output 1 and one
for Output 2) regardless of which of the outputs is enabled; however, ChemSTEER will only display the
appropriate output result(s) in the Estimated Releases subtab, as described above. The Output 1 model
parameters will be used as a set to calculate the Output 1 result values, and the Output 2 model
parameters will be used as a set to calculate the Output 2 result values.
Exposure Model Results
Each calculated exposure result is displayed in the following nine columns on the Exposures tab -
Activity Exposure Estimates subtab:
• Route of Exposure;
• Characterization of Results;
• Total Number of Workers;
• Exposure Days per Year;
• Estimate Potential Dose Rate (mg/worker-day);
• Lifetime Average Daily Dose (mg/kg-day);
• Average Daily Dose (mg/kg-day);
• Acute Potential Dose (mg/kg-day); and
• Basis.
The Characterization of Results column contains the characterization settings for each of the
output sets (i.e., Output 1 and Output 2) for each route of exposure.
Based on the enable/disable status of the Enable Model Parameters for Output 1 and Enable
Model Parameters for Output 2 boxes in the View/Update Exposure Model Information screen when the
Run Model(s) button is clicked, the appropriate exposure results are displayed in the Activity Exposure
Estimates subtab in one or two rows for each route of exposure.
144
-------
ChemSTEER User Guide - Updated May 2015
The values displayed in the columns are derived by running the model calculation. When the
Run Model(s) button is clicked, the model will perform two calculations (i.e., one for Output 1 and one
for Output 2) regardless of which of the outputs is enabled; however, ChemSTEER will only display the
appropriate output result(s) in the Activity Exposure Estimates subtab, as described above. The Output 1
model parameters will be used as a set to calculate the Output 1 result values, and the Output 2 model
parameters will be used as a set to calculate the Output 2 result values.
Passing Vapor Generation Parameters from the Air Release Model to the Inhalation Exposure
Model
When the release of a volatile chemical is assessed in ChemSTEER, the release model calculates
a vapor generation rate (G). This parameter is then used to calculate the daily release of the chemical to
air. To read more about these types of release models, go to the Models for Calculating Releases to Air
section of this User Guide.
The G parameter, as well as other model input parameters (e.g., hours per day, the vapor
pressure correction factor (X), and the chemical's vapor pressure), that are calculated or set in the
selected release model are then passed to and used by the EPA/OPPT Mass Balance Inhalation Model to
calculate the corresponding worker exposure to the chemical vapor on the Exposures tab.
In general, the Output 1 release model parameters will be passed to the Output 1 exposure
model parameters and the Output 2 release model parameters will be passed to the Output 2 exposure
model parameters. Because ChemSTEER only calculates model outputs, such as G, for enabled outputs,
ChemSTEER may substitute values from a non-corresponding output if only one release output is
enabled. In order to insure transfer of linked values from release models to exposure models, you
should always re-run the release models after updating release values and re-run the exposure models
to incorporate these new values in the exposure results.
Example 1: You choose to run a vapor generation air release model (e.g., the EPA/OAQPS AP-42
Loading Model) in the Releases tab for Output 2 only. You also modify the hours per day (OHa) of the
release from a default of 4 hours per day to 1 hour per day and run or re-run the models.
You then wish to calculate a range of inhalation exposure values using the EPA/OPPT Mass
Balance Inhalation Model by enabling both the Output 1 and Output 2 results. The inhalation model
hours per day (h) for Output 2 will default to the user-specified OHa for the release (1 hour per day). In
addition, Output 1 for the exposure model will be set to the only enabled release model OHa value of 1
hour per day.
If you wish to modify the exposure model Output 1 duration, you may enter user-specified
values for the desired parameters in the View/Update Inhalation Model Information window, provided
they are independently used by the inhalation model equations. If you wish to modify a parameter that
is passed from the air release model (e.g., G, duration, etc.), it is recommended that you return to the
Releases tab, click on the View/Update Model Information button, enable Output 1 parameters, enter
the desired Output 1 duration (OHa), and re-run the air release model to re-calculate the G value for
Output 1. By changing the duration in the release model, ChemSTEER will calculate the appropriate G
value for that duration and pass both values to the inhalation exposure model. ChemSTEER will not
prohibit you from changing the duration for Output 1 in the exposure model; however, it will not
correspond with the G value that was calculated using the release model defaults.
145
-------
ChemSTEER User Guide - Updated May 2015
Example 2: You choose to run a vapor generation air release model for Output 2 only, as
described in Example 1 above.
You then wish to calculate a single inhalation exposure value for Output 1 only (i.e., Output 2
parameters are disabled). In this case, the exposure model Output 1 parameters will default to the
appropriate release model Output 2 values (e.g., vapor generation rate (G) and the duration hours per
day). If you later enable the exposure model Output 2 parameters, they will initially default to the
exposure model Output 2 values, as specified in the model User Guide topic, and any linked values from
the release model Output 2 parameters. If you wish to calculate two results for the exposure model, you
may enter user-specified values for the desired parameters in the View/Update Inhalation Model
Information window, provided they are independently used by the inhalation model equations. If you
wish to modify a parameter that is passed from the air release model (e.g., G, duration, etc.) you must
follow the instructions described for Example 1.
Dual Outputs in the IRER
If the IRER report is generated while either or both of the Enable Model Parameters for Output 1
and Enable Model Parameters for Output 2 boxes are checked, it will include one or both sets of the
calculated results, as appropriate.
The "Release Total" (appearing in the IRER only) is calculated by adding together all releases
from all sites over all days. Within a release, ChemSTEER will use the greater value from either the
Output 1 or Output 2 result for the Release Total.
To read more about the IRER report, go to the IRER Format Details topic.
Environmental Releases
General Guidelines for Release Assessment
Detailed descriptions of the environmental release models are contained in several User Guide
topics, organized according to the type of release (e.g., liquid or solid) and media of release (e.g., to air
or other media). Simply click on the desired grouping of models in the User Guide Table of Contents to
access these detailed descriptions.
Each manufacturing, processing, and use operation to be assessed is analyzed to determine the
sources/activities that can result in releases to the environment that are to be estimated. Once these
sources/activities are identified, a general hierarchy of preference may be used to determine how to
quantify each release from each source/ activity. The following list shows the potential methods for
quantifying releases in order (generally) from the most preferred to the least preferred:
1. Measured release monitoring data for the chemical, including concentration and flow
rate monitoring data.
2. Measured release monitoring data for a "surrogate" chemical with similar "release-
affecting" properties and used in the same (or very similar) process.
3. Modeled release estimates:
146
-------
ChemSTEER User Guide - Updated May 2015
• Simulated release estimates (e.g. process design software or mathematical model)
for the chemical.
• Regulated limits as an estimated "upper bound" of release.
• "Rule-of-thumb" release estimates, or those developed using analogous points of
reference and engineering judgment.
This order of preference is expected to apply generally to most cases of release assessment.
However, judgment may dictate that, in some cases, the order within the hierarchy should be changed.
Examples of such a change of hierarchy order may include when data are judged to be unreliable or
unrepresentative for a particular reason. Also, some estimates may be a combination of two or more of
these methods.
Estimation methods in ChemSTEER are based on a combination of factors:
• Research and knowledge of and data from unit operations and industrial processes,
• Some basic chemical engineering principles, and
• Professional experience and judgment.
The standard methods and models in ChemSTEER have been developed to estimate releases for
a variety of industrial and commercial operations.
Quick Summary of ChemSTEER Release Models
All of the ChemSTEER release models are summarized in the table below. For each model, a
brief description of the primary calculation(s), as well as a list of the ChemSTEER release sources (or
source categories) that use the model as the default for calculating releases, is provided.
NOTE: This table is intended to provide you a "snapshot" of the various ChemSTEER models to
help you become more familiar with them. You are highly encouraged to review the full description of
the models (provided in this section of the User Guide), as well as the source/activity topics (provided in
the Release Sources and Exposure Activities section of the User Guide), for a more complete description
of the calculations and logic used.
147
-------
ChemSTEER User Guide - Updated May 2015
Quick Summary of ChemSTEER Release Models
Release Model
Brief Description of Calculation or Basis of Daily Chemical
Release (kg/site-day)
Sources That Use the Model as a Default for
Calculating Releases
Models for Calculating Releases of Chemical Vapor to Air
NOTE: These models only appear as default for calculating release of a volatile chemical (i.e., the adjusted vapor pressure (AVP) of the material being handled
is within the specified AVP range).
EPA/OAQPS AP-42 Loading Model
Daily Release=G x OHa x (3600 s/hr)/(1000 g/kg)
Where:
G*=vaporization rate (g/s) (uses model equation for loading
activities)
OHa=hours per site-day for the activity
*Be sure to read this model's User Guide topic for more
information on how the vaporization rate is calculated.
Loading Liauids into Transport Containers/Vessels (all
source types)
EPA/OPPT Mass Transfer Coefficient
Model
(Use for OUTDOOR sources of release)
Daily Release=G x OHa x (3600 s/hr)/(1000 g/kg)
Where:
G*=vaporization rate (g/s) (uses model equation for
OUTDOOR sources)
OHa=hours per site-day for the activity
*Be sure to read this model's User Guide topic for more
information on how the vaporization rate is calculated.
Cleaning Liauid Residuals from Tank Trucks Used to
Transport Raw Material/Product
Cleaning Liauid Residuals from Rail Cars Used to
Transport the Raw Material/Product
Eauipment Cleaning Losses of Liauids (all source
types)
EPA/OPPT Penetration Model
(Use for INDOOR sources of release)
Daily release=G x OHa x (3600 s/hr)/(1000 g/kg)
Where:
G*=vaporization rate (g/s) (uses model equation for INDOOR
sources)
OHa=hours per site-day for the activity
*Be sure to read this model's User Guide topic for more
information on how the vaporization rate is calculated.
Cleaning Liauid Residuals from Bottles Used to
Transport the Raw Material/Product
Cleaning Liauid Residuals from Small Containers Used
to Transport the Raw Material/Product
Cleaning Liauid Residuals from Totes Used to
Transport the Raw Material/Product
Cleaning Liquid Residuals from Storage/Transport
148
-------
ChemSTEER User Guide - Updated May 2015
Vessels (user-defined material)
Sampling Liauids (all source tvpes)
User-Defined Vapor Generation Rate
Model
Daily release=G x OHa x (3600 s/hr)/(1000 g/kg)
Where:
G=vaporization rate (g/s) (you must enter a value)
OHa=hours per site-day for the activity
Vapor Releases from Open Liquid Surfaces
NOTE: You may choose this model for any source for
which you wish to enter a known value for G.
EPA/OPPT Cooling Tower Evaporative
Loss Model
(Used in the Recirculating Water-
Cooling Tower Additive Use operation)
Daily release=LF x Amt
Where:
LF=loss fraction; between 0.5 and 3 percent (the loss
fraction must be entered and used in the Mass Balance
Parameters subtab calculations)
Amt=Daily amount of chemical contained in the recirculating
fluid (DRRchem) (kg/site-day) (value must be
entered/calculated in the Mass Balance Parameters subtab)
Recirculating Water-Cooling Tower Additive Releases
NOTE: This model cannot be chosen as an alternative
for any other ChemSTEER sources.
Models for Calculatina Releases from Transport Container Residues to Non-Air Media (i.e.. water, incineration, and/or landfill)
EPA/OPPT Bulk Transport Residual
Model
Daily release=LF x Amt
Where:
LF=loss fraction; up to 0.2 percent
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
Cleaning Liauid Residuals from Totes Used to
Transport the Raw Material/Product
Cleaning Liauid Residuals from Tank Trucks Used to
Transport the Raw Material/Product
Cleaning Liauid Residuals from Rail Cars Used to
Transport the Raw Material/Product
EPA/OPPT Drum Residual Model
Daily Release=LF x Amt
Where:
Cleaning Liauid Residuals from Drums Used to
Transport the Raw Material/Product
149
-------
ChemSTEER User Guide - Updated May 2015
LF=loss fraction; up to 3 percent
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
Cleaning Liauid Residuals from Containers (user-
defined) Used to Transport the Raw
Material/Product
Cleaning Liquid Residuals from Storage/Transport
Vessels (user-defined material)
EPA/OPPT Small Container Residual
Model
Daily release=LF x Amt
Where:
LF=loss fraction; up to 0.6 percent
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
Cleaning Liauid Residuals from Bottles Used to
Transport the Raw Material/Product
Cleaning Liauid Residuals from Small Containers Used
to Transport the Raw Material/Product
EPA/OPPT Solid Residuals in Transport
Containers Model
Daily release=LF x Amt
Where:
LF=loss fraction; 1 percent
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
Cleaning Solid Residuals from Transport
Containers/Vessels (all source types)
Eauipment Cleaning Losses of Solids
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
Models for Calculatina Releases from Process Eauipment Vessel Cleanina Residues to Non-Air Media (i.e.. water, incineration, and/or landfill)
EPA/OPPT Multiple Process Vessel
Daily release=LF x Amt
Eauipment Cleaning Losses of Liauids from Multiple
150
-------
ChemSTEER User Guide - Updated May 2015
Where:
LF=loss fraction; 2 percent
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
Vessels
EPA/OPPT Single Process Vessel
Daily release=LF x Amt
Eauipment Cleaning Losses of Liauids from a Single
Residual Model
Vessel (all source tvpes)
Where:
LF=loss fraction; up to 1 percent
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
::
determined.
EPA/OPPTSolid Residuals in Transport [ Daily release=LF x Amt
Containers Model
Where:
LF=loss fraction; 1 percent
Cleaning Solid Residuals from Transport
Containers/Vessels (all source types)
Equipment Cleaning Losses of Solids
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
Models for Calculating Releases from Industry-Specific Sources
151
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT Automobile OEM Coating
Overspray Loss Model (non-volatile)
(used in the Automobile OEM Spray
Coating Operation)
Daily release=LF x Amt
Where:
LF=loss fraction; 1-TE
TE=transfer efficiency of the spray gun (25-65%)
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
This model also uses the mist capture technology (e.g. dry
filter or waterwash) to determine portions of the
oversprayed amount that is released to the air, water, and
incineration, or landfill targets.
Automobile OEM Spray Coating Application
EPA/OPPT Automobile Refinish
Coating Overspray Loss Model (non-
volatile)
(used in the Automobile Refinish Spray
Coating Operation)
Daily release=LF x Amt
Where:
LF=loss fraction; 1-TE
TE=transfer efficiency of the spray gun (25-65%)
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
This model also uses the mist capture technology (e.g. dry
filter or waterwash) to determine portions of the
oversprayed amount that is released to the air, water, and
incineration, or landfill targets.
Automobile Refinish Spray Coating Application
EPA/OPPT Cooling Tower Blowdown
Loss Model
Daily release=LF x Amt
Where:
Recirculating Water-Cooling Tower Additive Releases
NOTE: This model cannot be chosen as an alternative
152
-------
ChemSTEER User Guide - Updated May 2015
(used in the Recirculating Water-
Cooling Tower Additive Use operation)
LF=loss fraction; 0.6 percent (the loss fraction must be
entered and used in the Mass Balance Parameters subtab
calculations)
Amt=Daily amount of chemical contained in the recirculating
fluid (DRRchem) (kg/site-day) (value must be
entered/calculated in the Mass Balance Parameters subtab)
for any other ChemSTEER sources.
EPA/OPPT Cooling Tower Windage
Loss Model
(used in the Recirculating Water-
Cooling Tower Additive Use operation)
Daily release=LF x Amt
Where:
LF=loss fraction; 0.1 percent (the loss fraction must be
entered and used in the Mass Balance Parameters subtab
calculations)
Amt=Daily amount of chemical contained in the recirculating
fluid (DRRchem) (kg/site-day) (value must be
entered/calculated in the Mass Balance Parameters subtab)
Recirculating Water-Cooling Tower Additive Releases
NOTE: This model cannot be chosen as an alternative
for any other ChemSTEER sources.
EPA/OPPT Cooling Tower Evaporative Daily release=LF x Amt
Loss Model
Where:
(used in the Recirculating Water- 1 LF=loss fraction; between 0.5 to 3 percent (the loss fraction
Cooling Tower Additive Use operation) must be entered and used in the Mass Balance Parameters
subtab calculations)
NOTE: this model is only used in cases
where the chemical is volatile (i.e., the Amt=Daily amount of chemical contained in the recirculating
AVP of the additive is within the fluid (DRRchem) (kg/site-day) (value must be
specified AVP range) entered/calculated in the Mass Balance Parameters subtab)
Recirculating Water-Cooling Tower Additive Releases
NOTE: This model cannot be chosen as an alternative
for any other ChemSTEER sources.
EPA/OPPT Electroplating Rinse Water Daily release*=DVrinse x 3.78 L/gal x Yrinse x Drinse x (1-
Loss Model RinseE)
(used in the Electroplating Bath *Be sure to read this model's User Guide topic for more
Additive Use operation) information on how the daily amount of chemical is
determined.
This model also used the wastewater treatment system
efficiency to determine portions of the chemical amount
that is released to land or incineration (as sludge) and to
water.
Rinsing Electroplated Parts
NOTE: This model cannot be chosen as an alternative
for any other ChemSTEER sources.
153
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT Electroplating Spent Bath
Disposal Model
(used in the Electroplating Bath
Additive Use operation)
Daily release*=DVbath x 3.78 L/gal x Ybath x Dbath
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
This model also used the wastewater treatment system
efficiency to determine portions of the chemical amount
that is released to land or incineration (as sludge) and to
water
Changing Electroplating Bath
NOTE: This model cannot be chosen as an alternative
for any other ChemSTEER sources.
Models for Calculatina Releases from Other Generic Unit Operations to Multi-Media (i.e.. air. water, incineration, and/or landfill)
EPA/OPPT Water Saturation Loss
Model
Daily release=WSchem x CF x Amt / (1000 g/kg)
Where:
WSchem=water solubility of the chemical, g/L (default:
specified in the Chemical tab)
CF*=correction factor; default=l
Amt*=Amount of water (kg/site-day) in which the chemical
is saturated (e.g., mass of water contained in the vessel)
*Be sure to read this model's User Guide topic for more
information on using the correction factor and how the daily
amount of water is determined.
Aqueous Wash of Organic Mass
EPA/OPPT Solids Transfer Dust Model
Daily Release=LF x Amt
Where:
LF=loss fraction; 0.5 percent
Amt*=amount of chemical (kg/site-day) to which the loss
fraction is applied (e.g., daily amount unloaded from
container)
*Be sure to read this model's User Guide topic for more
information on how the daily amount of chemical is
determined.
Loading Solids into Transport Containers/Vessels (all
source types)
Unloading Solids from Transport Containers/Vessels
(all source types)
154
-------
ChemSTEER User Guide - Updated May 2015
This model also uses the solids removal efficiency of the
control technology (e.g., mechanical collector/cyclone) to
determine portions of the amount that is released to air,
water, incineration, or landfill targets.
User-Defined Loss Rate Model
Daily release=LF x Amt
Distillation Column Bottoms Disposal
Where:
Filter Media Changeout
LF=loss fraction (you must enter a loss fraction between 0
and 1)
Grinding and Sanding
Amt*=amount of chemical (kg/site-day) to which the loss
Liquid/Liquid Extraction Solvent Disposal
fraction is applied (e.g., chemical mass capacity of the
vessel)
Scrubber Releases
*Be sure to read this model's User Guide topic for more Roll Coating
information on how the daily amount of chemical is
determined. NOTE: You may choose this model for any source for
which you wish to enter a known loss fraction (LF)
value.
155
-------
ChemSTEER User Guide - Updated May 2015
U
Model Description
User-defined loss rate and associated parameters to calculate releases.
Sources/Activities That Use This Model as a Default
The following sources/activities use the User-Defined Loss Rate Model as the default for
calculating releases of a chemical to air, water, incineration, or landfill:
• Distillation Column Bottoms Disposal
• Filter Media Chaneeout
• Grinding and Sanding
• Liquid/Liquid Extraction Solvent Disposal
• Scrubber Releases
• Roll Coating
This model is appropriate to use as an additional or alternative release model for all other
ChemSTEER sources/activities (except the Recirculating Water-Cooling Tower Additive Releases
source/activity).
Potential Media of Release
Air, Water, Incineration, and/or Landfill (default: 100% of release to water)
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The User-Defined Loss Rate Model default values for each of the input parameters are
summarized in the table below.
Table A 1. Input Parameters and Default Values for the User-Defined Loss Rate Model
156
-------
ChemSTEER User Guide - Updated May 2015
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an amount of the
chemical that is estimated to be released
User-defined LF
dimensionless
Amt
The amount of chemical to which a loss
fraction is applied
Defaults specified in Table A- la
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of Operation Parameters tab)
site(s)
Freq
The frequency of release of the chemical
Default specified in Table A- lb
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
You may elect to change any parameter from Table A-1 except the model estimates DR and AR.
Clicking the Type column for each changeable parameter other than LF, Amt and Freq contains only two
options: ChemSTEER defaults from Table A-1 and User-defined. You must enter a value for LF in this
release model. The conditional default and non-default options for Amt and Freq are presented in the
tables below. Be sure to read the ChemSTEER Estimation Methods and Models topic for more
information about changing model parameters.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Output 1
Default Characterization of Output 2 Results: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"User-Defined Loss Rate Model"
157
-------
ChemSTEER User Guide - Updated May 2015
Table A-la. Conditional Default Values for Amt for the User-Defined Loss Rate Model
Source/Activity
Type/Operation
Mode
Batch Condition
Operation Type
Conditional Amt Default
(kg/site-day)
Non-default Options
for Amt*
Container-Related /
Continuous
Not Applicable
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of the
Operation Parameters
tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
DMIchem
DMOchem
User-defined Amt
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of the
Operation Parameters
tab)
Container-Related /
Batch
Any
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of the
Operation Parameters
tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
BMIchem
BMOchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
BMIchem x Nbd
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of the
Operation Parameters
tab)
Not Container-
Related / Continuous
Not Applicable
Manufacturing
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMIchem
User-defined Amt
158
-------
ChemSTEER User Guide - Updated May 2015
Processing
DMIchem (kg/site-day)
DMOchem
Use
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
User-defined Amt
Not Container-
Number of batches
Manufacturing
BMOchem (kg/line-bt)
BMIchem
Related / Batch
per day
(from Mass Balance
BMIchem x Ls
(Nbd)< 1
Parameters subtab of the
(kg/site-bt)
(from Mass Balance
Operation Parameters
tab)
BMOchem x Ls
Parameters subtab of
(kg/site-bt)
the Operation
Parameters tab)
User-defined Amt
Processing
BMIchem (kg/line-bt)
BMIchem
Use
(from Mass Balance
Parameters subtab of the
BMIchem x Ls
(kg/site-bt)
Operation Parameters
tab)
BMOchem x Ls
(kg/site-bt)
User-defined Amt
Number of batches
Manufacturing
BMOchem x Nbd
BMIchem
per day
BMOchem
(Nbd)> 1
(from Mass Balance
BMIchem x Nbd
(from Mass Balance
Parameters subtab of the
BMIchem x Nbd/Ls
(kg/line-day)
Parameters subtab of
the Operation
Operation Parameters
tab)
Parameters tab)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Processing
BMIchem x Nbd
BMIchem
Use
(kg/site-day)
(from the Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMOchem
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
159
-------
ChemSTEER User Guide - Updated May 2015
Table A-lb. Conditional Default Values for Freq for the User-Defined Loss Rate Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Container-
Related/Batch
Any
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release
Model Information screen in the Releases tab.
160
-------
ChemSTEER User Guide - Updated May 2015
Key Rationale for Model
NA
References
NA
Models for Calculating Releases to Air
'OAQPS AP-42 Loading Mode/
Model Description
This model estimates releases to air from the displacement of air containing chemical vapor as a
container/vessel is filled with liquid. This model determines a vapor generation rate (G) based in part
upon the chemical's physical-chemical properties and assumes that the rate of evaporation is negligible
compared to the loss from displacement.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OAQPS AP-42 Loading Model as the default for
calculating releases of a volatile chemical to air:
• All sources/activities involving Loading Liquids into Transport Containers/Vessels
• All sources/activities involving Unloading Liquids from Transport Containers/Vessels
(It is assumed that as the container is unloading, another is being loaded. The
EPA/OAQPS AP-42 Loading model provides a more conservative estimate of chemical
releases that occur during this activity.)
NOTE: If the adjusted vapor pressure for the operation (AVPrm or AVPprod) is outside of the
preferred AVP range, this model will NOT appear as a default. If the operation AVP is less than
the preferred AVPlow (0.001 torr) or greater than the preferred AVPhigh (35 torr), there is no
default model for estimating volatile releases to air from these activities. Refer to the Operation
Parameters Tab -> Shared Parameters/Factors Subtab for more information.
Other Sources/Activities
The EPA/OAQPS AP-42 Loading Model may be an appropriate alternative to the default air
release model for the following sources/activities:
• All sources/activities for Cleaning Liquid Residuals from Transport Containers/Vessels
• All sources/activities for Equipment Cleaning Losses of Liquids
• Miscellaneous Sources/Activities Related to Liquid Processing
• Aqueous Wash of Organic Mass
• Distillation Column Bottoms Disposal
161
-------
ChemSTEER User Guide - Updated May 2015
• Liquid/Liquid Extraction Solvent Disposal
Mechanism
Displacement of air containing chemical vapor.
Potential Media of Release
Air, Water, Incineration, and/or Landfill (default: 100% of release to air)
Equations
For daily releases:
DR (kg/site-day) = (G x 3600 x OHa) / 1000
DR occurs over [Freq] days/year
where:
G (g/s) = f x MW x (3785.4 x Vc) x r x X x (VP / 760) / (3600 x T x R)
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OAQPS AP-42 Loading Model default values for each of the input parameters are
summarized in Table A-2 below:
162
-------
ChemSTEER User Guide - Updated May 2015
Table A-2. Input Parameters and Default Values for the EPA/OAQPS AP-42 Loading Model
Parameter
Description
Default Value(s)
Units
G
Vapor generation rate
Calculated from model equation
g/s
f
Saturation factor
Defaults specified in Table A-2a
dimensionless
MW
Molecular weight of the chemical
MW
(from chemical tab)
g/mol
Vc
Volume of the container
VC
(from Container Parameter subtab of
Operation Parameters tab)
Defaults specified in Table A-2a
gallons
r
Fill rate
r
(from Container Parameter subtab of
Operation Parameters tab)
Defaults specified in Table A-2a
containers/hr
X
Vapor pressure correction factor (mole
fraction or other)
Defaults specified in Table A-2b
dimensionless
VP
Vapor pressure of the pure chemical
VP
(from chemical tab)
torr
T
Temperature
298
K
R
Universal Gas Constant
82.05
atm-cm3/gmol-
K
OHa
Operating hours per site-day for the
source/activity
Default specified in Table A-2c
hour/site-day
NS
Number of sites
NS
(from Mass Balance Parameters subtab
of Operation Parameters tab)
site(s)
Freq
The frequency of release of the
chemical to a particular medium
Defaults specified in Table A-2d
days/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
You may elect to change any parameter from Table A-2 except the model estimates G, DR, and
AR. Clicking the Type column for each changeable parameter other than X and Freq contains only two
options: ChemSTEER defaults from Table A-2 and User-defined. The default values of r, f, and h are
dependent upon the selected source/activity. These conditional default values are summarized in Table
A-2a and Table A-2c. The conditional default and non-default options for X and Freq are also presented
in the tables below. Be sure to read the ChemSTEER Estimation Methods and Models topic for more
information about changing model parameters.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
163
-------
ChemSTEER User Guide - Updated May 2015
Default Characterization of Output 1 Results: Typical
Default Characterization of Output 2 Results: Worst Case
NOTE: If you change the default value for either r or/, the Characterization of Results will be
automatically reset to Output 1 or Output 2 (as appropriate).
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OAQPS AP-42 Loading Model"
164
-------
ChemSTEER User Guide - Updated May 2015
Table A-2a. Default Values for Container Volumes (Vc), Fill Rates (r), and Saturation Factors (f) for
Activities Involving Liquids
Vessel Name
Default Vc
Range of Volumes
Default r1
Default f
(Characterization of Parameter Value)
(gal)
(gal)
(containers/hr)
Bottles
<5
Output 1 (Typical)
1
60
0.5
Output 2 (Worst Case)
1
60
1
Small Containers
> 5 to < 20
Output 1 (Typical)
5
60
0.5
Output 2 (Worst Case)
5
60
1
Drums
> 20 to <100
Output 1 (Typical)
55
20
0.5
Output 2 (Worst Case)
55
20
1
Totes
> 100 to < 1,000
Output 1 (Typical)
550
20
0.5
Output 2 (Worst Case)
550
20
1
Tank Truck
> 1,000 to < 10,000
Output 1 (Typical)
5,000
2
1
Output 2 (Worst Case)
5,000
2
1
Rail Car
> 10,000
Output 1 (Typical)
20,000
1
1
Output 2 (Worst Case)
20,000
1
1
User-defined or
User-defined
User-defined
User-defined
Sources/Activities that are not
Container-Related
Source: portions from CEB Engineering Manual, USEPA, 1991, Table 4-11.
1. ChemSTEER defaults to the typical container fill rate (r) listed in the background reference document for all
vapor generation estimates for container-related sources/activities. The background reference document contains
worst case fill rates that would result in higher vapor generation rates; however, these are not used as default
values in ChemSTEER. For a fixed total volume of liquid handled, the worst case fill rate would result in a higher
generation rate that would occur over a shorter period of time, when compared to that of the typical fill rate
(lower generation rate over longer period of time). Thus, with all other parameters being equal, the total annual
amount of vapor generated (and resulting releases to air and worker inhalation exposures) are essentially
equivalent between the typical and worst case fill rates. For simplicity, ChemSTEER uses the typical fill rate as the
default for both Output 1 and Output 2 results. Alternative typical fill rates for smaller containers and bottles were
developed as an internal policy decision. The typical rate of 60 containers per hour is the current default; a worst
case fill rate of 90 per hour was also decided. The reference document contains the previous defaults of 20
(typical) and 30 (worst case) containers per hour for bottles and small containers; however, these were
superseded by this internal policy decision.
165
-------
ChemSTEER User Guide - Updated May 2015
Table A-2b. Conditional Default Values for X for the EPA/OAQPS AP-42 Loading Model
Material Named in
Source/Activity Label
Operation
Type
Conditional X Default
Non-Default
Options for X*
Raw Material
Any
Xrm
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xprod
Xother
User-defined X
Product
Any
Xprod
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xother
User-defined X
Other
Any
Xother
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xprod
User-defined X
Not material-specific
Manufacture
Xprod
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xother
User-defined X
Processing
Use
Xrm
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xprod
Xother
User-defined X
*Non-default options for X are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab. All default and non-default options for X are available for both Output 1
and Output 2.
Table A-2c. Conditional Default Values for OHa for the EPA/OAQPS AP-42 Loading Model
Source/Activity Type
Conditional h Default*
(hr/site-day)
Container-Related
OHa (from Container Parameters subtab
of the Operation Parameters tab)
Sampling
1
Equipment Cleaning Losses of Liquids from Multiple Vessels
4
Equipment Cleaning Losses of Liquids from a Single, Large Vessel
1
Equipment Cleaning Losses of Liquids from a Single, Small Vessel
0.5
Not Container-Related, Sampling, or Equipment Cleaning
8
1. You may select the conditional default h (shown above) or enter a user-defined h for either Output 1 or Output
2. for all sources/activities. The conditional default h values were adopted as a policy decision in 2002.
166
-------
ChemSTEER User Guide - Updated May 2015
Table A-2d. Conditional Default Values for Freq for the EPA/OAQPS AP-42 Loading Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options for
Freq*
Container-
Related/Continuous
Not Applicable
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Ncy (Containers/site-yr;
from Container
Parameters subtab of the
Operation Parameters
tab)
OD
User-defined Freq
Container-
Related/Batch
Any
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Ncy (Containers/site-yr;
from Container
Parameters subtab of the
Operation Parameters
tab)
Nby
OD
User-defined Freq
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab. All default and non-default options for Freq are available for both Output 1
and Output 2.
Key Rationale for Model
As a container/vessel is filled with liquid containing the chemical, some of the chemical in the
liquid evaporates into the air in the vessel. The air containing the chemical vapor leaves the vessel at the
rate at which the liquid fills the vessel.
167
-------
ChemSTEER User Guide - Updated May 2015
Reference
Chemical Engineering Branch Manual for the Preparation of Engineering Assessments,
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991.
(Equation 4-21)
Fehrenbacher, M.C. and Hummel, A.A. "Evaluation of the Mass Balance Model Used by the
Environmental Protection Agency for Estimating Inhalation Exposure to New Chemical
Substances". American Industrial Hygiene Association Journal. June 1996. 57: 526-536.
Model Description
This model estimates releases to air from evaporation of a chemical from an open, exposed
liquid surface. This method is the default for select activities that are assumed to be performed
outdoors or when air velocities are expected to be greater than 100 feet per minute. This model
determines a vapor generation rate (G) based in part upon the chemical's physical-chemical properties
and the surface area from which the chemical is evaporating.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Mass Transfer Coefficient Model as the
default for calculating releases of a volatile chemical to air:
• Cleaning Liquid Residuals from Tank Trucks Used to Transport the Raw Material/Product
(see Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Rail Cars Used to Transport the Raw Material/Product
(see Cleaning Liquid Residuals from Transport Containers/Vessels)
• All sources/activities involving for Equipment Cleaning Losses of Liquids
NOTE: If the adjusted vapor pressure for the operation (AVPrm or AVPprod) is outside of the
preferred AVP range, this model will NOT appear as a default. If the operation AVP is less than
the preferred AVPlow (0.001 torr) or greater than the preferred AVPhigh (35 torr), there is no
default model for estimating volatile releases to air from these activities. Refer to the Operation
Parameters Tab -> Shared Parameters/Factors Subtab for more information.
Other Sources/Activities
The EPA/OPPT Mass Transfer Model may be an appropriate alternative to the default air release
model for the following sources/activities:
Cleaning Liquid Residuals from Transport Containers/Vessels:
• Cleaning Liquid Residuals from Bottles Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Small Containers Used to Transport the Raw
Material/Product
168
-------
ChemSTEER User Guide - Updated May 2015
• Cleaning Liquid Residuals from Drums Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Totes Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Containers Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Storage/Transport Vessels (User-defined)
Unit Operations and Processes:
Aqueous Wash of Organic Mass
Filter Media Chaneeout
Liquid/Liquid Extraction Solvent Disposal
• Scrubber Releases
Other Sources/Activities:
• All sources/activities for Sampling Liquids
• All sources/activities for Unloading Liquids from Transport Containers/Vessels
• Miscellaneous Sources/Activities Related to Liquid Processing
• Vapor Releases from Open Liquid Surfaces
Roll Coating
Mechanism
Volatilization of the chemical from a static pool.
Potential Media of Release
Air, Water, Incineration, and/ or Landfill (default: 100% of release to air)
Equations
For daily releases:
DR (kg/site-day) = (G x 3600 x OHa) / 1000
DR occurs over [Freq] days/year
where:
1.93x10"7 xMW0'78 xXx VP x (1/29 +1/MW)0,33 xvz0,78 x A
G(g/s)=-
(T0-4 x d011 x (T°-5-5.87)2/3)
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined.
169
-------
ChemSTEER User Guide - Updated May 2015
Model Input Parameters and Default Values
The EPA/OPPT Mass Transfer Model input parameters contain several default values that are
dependent upon the specific type of activity being assessed. The EPA/OPPT Mass Transfer Model default
values for each of the input parameters are summarized in Table A-3:
Table A-3. Equipment Cleaning Activity Input Parameters and Default Values for the EPA/OPPT Mass
Transfer Model
Parameter
Description
Default Value(s)
Units
G
Vapor generation rate
Calculated from model equation
g/s
MW
Molecular weight of the chemical
MW
(from Chemical tab)
g/mol
X
Vapor pressure correction factor
(mole fraction or other)
Defaults specified in Table A-3a
dimensionless
VP
Vapor pressure of the pure chemical
VP
(from Chemical tab)
torr
vz
Air speed
440
ft/min
d
Diameter/length of the static pool
or opening
Defaults specified in Table A-3b
cm
A
Surface area of the static pool or
opening
ji x d2/4
cm2
T
Temperature
298
K
OHa
Operating hours per site-day for the
source/activity
Defaults specified in Table A-3b
hours/site-day
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of Operation Parameters
tab)
site(s)
Freq
The frequency of release of the
chemical to air
Defaults specified in Table A-3c
days/site-year
DR
Daily release rate
Calculated from model equation
kg/site-day
AR
Annual release rate
Calculated from model equation
kg/year (all sites)
You may elect to change any parameter from Table A-3 except the model estimates G, A, DR,
and AR. Clicking the Type column for each changeable parameter other than X and Freq contains only
two options: ChemSTEER defaults from Table A-3 and User-defined. The default values of OHa and d are
dependent upon the selected source/activity. These conditional default values are summarized in Table
A-3b. The conditional default and non-default options for X and Freq are presented in the tables below.
Be sure to read the ChemSTEER Estimation Methods and Models topic for more information about
changing model parameters.
If you attempt to use an air speed (vz) less than or equal to 100 ft/min, ChemSTEER will allow
you to continue after viewing the following message box:
This model is most appropriate for air speeds greater than 100 ft/min. For air speeds
less than or equal to 100 ft/min, you should select and use the EPA/OPPT Penetration
Model to estimate the vapor generation rate.@
170
-------
ChemSTEER User Guide - Updated May 2015
Default Parameter Value Switch Settings and Results Characterization
When this model is used by a liquid sampling source/activity:
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
When this model is used by any other (non-liquid sampling) source/activity:
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Output 1
Default Characterization of Output 2 Results: Output 2
These result characterizations are the default for all sources/activities using the EPA/OPPT Mass
Transfer Coefficient Model.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Mass Transfer Coefficient Model"
Table A-3a. Conditional Default Values for X for the EPA/OPPT Mass Transfer Model
Material Named in
Source/Activity Label
Operation
Type
Conditional X Default
Non-Default
Options for X*
Raw Material
Any
Xrm
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xprod
Xother
User-defined X
Product
Any
Xprod
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xother
User-defined X
Other
Any
Xother
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xprod
User-defined X
Not material-specific
Manufacture
Xprod
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xother
User-defined X
Processing
Use
Xrm
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xprod
Xother
User-defined X
*Non-default options for X are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab. All default and non-default options for X are available for both Output 1
and Output 2.
171
-------
ChemSTEER User Guide - Updated May 2015
Table A-3b. Default Values for Operation Hours (OHa) and Pool/Opening Diameter (d) for the
EPA/OPPT Mass Transfer Model
Source/Activity Type
Default OHa1
(hrs/site-day)
Default d2
(cm)
Container-Related
OHa
(from Container Parameters
subtab of Operation Parameters
tab)
5.08 (2-in operating) for Vc <
5,000 gal
7.6 (3-in opening) for Vc >
5,000 gal
Equipment Cleaning Losses of Liquids from
Multiple Vessels
4
92 (3-ft manhole)
Equipment Cleaning Losses of Liquids from
a Single, Large Vessel
1
92 (3-ft manhole)
Equipment Cleaning Losses of Liquids from
a Single, Small Vessel
0.5
92 (3-ft manhole)
Sampling Liquid Product
Sampling Liquid Raw Material
Sampling Liquids
1
Output 1:
Default: 2.53 (Tvoical) (1-in
bottle opening)
Non-default options: 10
(Worst Case) and User-defined
d
Output 2:
Default: 10 (Worst Case) (4-in
beaker opening)
Non-default options: 2.53
(Typical) and User-defined d
All other sources/activities not covered by
above for continuous operations
24
User-defined
All other sources/activities not covered by
above for batch operations
Lesser of 24 or (HB x Nbd)
(from Mass Balance subtab of
Operations Parameters tab)
User-defined
1. You may select the conditional default OHa (shown above) or enter a user-defined OHa for either Output 1 or
Output 2 for all sources/activities. The conditional default OHa values were adopted as a policy decision in 2002.
2. For non-sampling sources activities, you may select the conditional default d (shown above) or enter a user-
defined d for either Output 1 or Output 2.
3. The "typical" diameter default value of 2.5 cm was adopted as a policy decision in 2002, which supersedes the
previous default value of 7 cm shown in the 1991 USEPA reference document.
172
-------
ChemSTEER User Guide - Updated May 2015
Table A-3c. Conditional Default Values for Freq for the EPA/OPPT Mass Transfer Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options for
Freq*
Container-
Related/Continuous
Not Applicable
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Ncy (Containers/site-yr;
from Container
Parameters subtab of the
Operation Parameters
tab)
OD
User-defined Freq
Container-
Related/Batch
Any
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Ncy (Containers/site-yr;
from Container
Parameters subtab of the
Operation Parameters
tab)
Nby
OD
User-defined Freq
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab. All default and non-default options for Freq are available for both Output 1
and Output 2.
Key Rationale for Model
The model is predicated on the solution of the classical mass transfer coefficient model with the
gas-phase mass transfer coefficient estimated by the correlation of Mackay and Matsugu. Results were
tested against experimental results on 19 compounds generated by four different experimenters over a
wide range of experimental conditions. The model matched the experimental data well, usually within
20 percent.
References
Pre-publication draft article entitled Evaporation of Pure Liquids From Open Surfaces, Fredrick C.
Arnold and Alfred J. Engel, US EPA, October, 1999.
173
-------
ChemSTEER User Guide - Updated May 2015
Chemical Engineering Branch Manual for the Preparation of Engineering Assessments,
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991.
EPA/OPPTPenetration Model
Model Description
This model estimates releases to air from evaporation of a chemical from an open, exposed
liquid surface. This method is the default for select activities that are assumed to be performed indoors
or when air velocities are expected to be less than or equal to 100 feet per minute. This model
determines a vapor generation rate (G) based in part upon the chemical's physical-chemical properties
and the surface area from which the chemical is evaporating.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Penetration Model as the default for
calculating releases of a volatile chemical to air:
• Cleaning Liquid Residuals from Bottles Used to Transport the Raw Material/Product (see
Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Small Containers Used to Transport the Raw
Material/Product (see Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Drums Used to Transport the Raw Material/Product (see
Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Totes Used to Transport the Raw Material/Product (see
Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Storage/Transport Vessels (User-defined) (see Cleaning
Liquid Residuals from Transport Containers/Vessels)
• All sources/activities for Sampling Liquids
NOTE: If the adjusted vapor pressure for the operation (AVPrm or AVPprod) is outside of the
preferred AVP range, this model will NOT appear as a default. If the operation AVP is less than
the preferred AVPlow (0.001 torr) or greater than the preferred AVPhigh (35 torr), there is no
default model for estimating volatile releases to air from these activities. Refer to the Operation
Parameters Tab -> Shared Parameters/Factors Subtab for more information.
Other Sources/Activities
The EPA/OPPT Penetration Model may be an appropriate alternative to the default air release
model for the following sources/activities:
Cleaning Liquid Residuals from Transport Containers/Vessels:
• Cleaning Liquid Residuals from Tank Trucks Used to Transport the Raw Material/Product
• Cleaning Liquid Residuals from Rail Cars Used to Transport the Raw Material/Product
174
-------
ChemSTEER User Guide - Updated May 2015
• Cleaning Liquid Residuals from Containers Used to Transport the Raw Material/Product
Unit Operations and Processes:
• Aqueous Wash of Organic Mass
• Filter Media Changeout
• Liquid/Liquid Extraction Solvent Disposal
• Scrubber Releases
Other Sources/Activities:
• All sources/activities for Sampling Liquids
• All sources/activities for Unloading Liquids from Transport Containers/Vessels
• Miscellaneous Sources/Activities Related to Liquid Processing
• Vapor Releases from Open Liquid Surfaces
Roll Coating
Mechanism
Volatilization of the chemical from a static pool.
Potential Media of Release
Air, Water, Incineration, and/ or Landfill (default: 100% of release to air)
Equations
For daily releases:
DR (kg/site-day) = (G x 3600 x OHa) / 1000
DR occurs over [Freq] days/year
where:
8.24x10"8 x MW0-835 x X x VP x (1/29+1/MW)0 25 x vz0-5 x A
G(g/S)= (t0.05 x d0-5 x P0-5)
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
175
-------
ChemSTEER User Guide - Updated May 2015
The EPA/OPPT Penetration Model input parameters contain several default values that are
dependent upon the specific type of activity being assessed. The EPA/OPPT Penetration Model default
values for each of the input parameters are summarized in Table A-4:
Table A-4. Input Parameters and Default Values for the EPA/OPPT Penetration Model
Parameter
Description
Default Value(s)
Units
G
Vapor generation rate
Calculated from model equation
g/s
MW
Molecular weight of the chemical
MW
(from Chemical tab)
g/mol
X
Vapor pressure correction factor
(mole fraction or other)
Defaults specified in Table A-4a
dimensionless
VP
Vapor pressure of the pure chemical
VP
(from Chemical tab)
torr
vz
Air speed
100
ft/min
d
Diameter/length of the static pool
or opening
Defaults specified in Table A-4b
cm
A
Surface area of the static pool or
opening
ji x d2/4
cm2
T
Temperature
298
K
P
Ambient atmospheric pressure
1
atm
OHa
Operating hours per site-day for the
source/activity
Defaults specified in Table A-4b
hours/site-day
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of Operation Parameters
tab)
site(s)
Freq
The frequency of release of the
chemical to air
Defaults specified in Table A-4c
days/site-year
DR
Daily release rate
Calculated from model equation
kg/site-day
AR
Annual release rate
Calculated from model equation
kg/year (all sites)
You may elect to change any parameter from Table A-4 except the model estimates G, A, DR,
and AR. Clicking the Type column for each changeable parameter other than X and Freq contains only
two options: ChemSTEER defaults from Table A-4 and User-defined. The default values of OHa and d are
dependent upon the selected source/activity. These conditional default values are summarized in Table
A-4b. The conditional default and non-default options for X and Freq are presented in the tables below.
Be sure to read the ChemSTEER Estimation Methods and Models topic for more information about
changing model parameters.
If you attempt to use an air speed greater than 100 ft/min, ChemSTEER will allow you to
continue after viewing the following message box:
"This model is most appropriate for air speeds less than or equal to 100 ft/min. For air
speeds greater than 100 ft/min, you should select and use the EPA/OPPT Mass Transfer
Model to estimate the vapor generation rate."
176
-------
ChemSTEER User Guide - Updated May 2015
Default Parameter Value Switch Settings and Results Characterization
When this model is used by a liquid sampling source/activity:
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
Settings for either Output 1 or Output 2 results for liquid sampling sources/activities are
based on which default diameter (d) is selected for the corresponding output (refer to
Table A-4b below):
• Results using the high end diameter (10 cm) are characterized as Worst-Case by
default.
• Results using the typical diameter (2.5 cm) are characterized as Typical by default.
• If you enter a user-defined diameter, the results are characterized as Output 1 or
Output2, as appropriate.
When this model is used by any other (non-liquid sampling) source/activity:
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Output 1
Default Characterization of Output 2 Results: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Penetration Model"
177
-------
ChemSTEER User Guide - Updated May 2015
Table A-4a. Conditional Default Values for X for the EPA/OPPT Penetration Model
Material Named in
Source/Activity Label
Operation
Type
Conditional X Default
Non-Default
Options for X*
Raw Material
Any
Xrm
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xprod
Xother
User-defined X
Product
Any
Xprod
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xother
User-defined X
Other
Any
Xother
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xprod
User-defined X
Not material-specific
Manufacture
Xprod
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xrm
Xother
User-defined X
Processing
Use
Xrm
(from Shared Parameters/Factors subtab of
the Operation Parameters tab)
Xprod
Xother
User-defined X
*Non-default options for X are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab. All default and non-default options for X are available for both Output 1
and Output 2.
178
-------
ChemSTEER User Guide - Updated May 2015
Table A-4b. Default Values for Operation Hours (OHa) and Pool/Opening Diameter (d) for the
EPA/OPPT Penetration Model
Source/Activity Type
Default OHa1
(hrs/site-day)
Default d2
(cm)
Container-Related
OHa
(from Container Parameters
subtab of Operation Parameters
tab)
5.08 (2-in operating) for Vc <
5,000 gal
7.6 (3-in opening) for Vc >
5,000 gal
Equipment Cleaning Losses of Liquids from
Multiple Vessels
4
92 (3-ft manhole)
Equipment Cleaning Losses of Liquids from
a Single, Large Vessel
1
92 (3-ft manhole)
Equipment Cleaning Losses of Liquids from
a Single, Small Vessel
0.5
92 (3-ft manhole)
Sampling Liquid Product
Sampling Liquid Raw Material
Sampling Liquids
1
Output 1:
Default: 2.53 (Tvoical) (1-in
bottle opening)
Non-default options: 10
(Worst Case) and User-defined
d
Output 2:
Default: 10 (Worst Case) (4-in
beaker opening)
Non-default options: 2.53
(Typical) and User-defined d
All other sources/activities not covered by
above for continuous operations
24
User-defined
All other sources/activities not covered by
above for batch operations
Lesser of 24 or (HB x Nbd)
(from Mass Balance subtab of
Operations Parameters tab)
User-defined
1. You may select the conditional default OHa (shown above) or enter a user-defined OHa for either Output 1 or
Output 2 for all sources/activities. The conditional default OHa values were adopted as a policy decision in 2002.
2. For non-sampling sources activities, you may select the conditional default d (shown above) or enter a user-
defined d for either Output 1 or Output 2.
3. The "typical" diameter default value of 2.5 cm was adopted as a policy decision in 2002, which supersedes the
previous default value of 7 cm shown in the 1991 USEPA reference document.
179
-------
ChemSTEER User Guide - Updated May 2015
Table A-4c. Conditional Default Values for Freq for the EPA/OPPT Penetration Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options for
Freq*
Container-
Related/Continuous
Not Applicable
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Ncy (Containers/site-yr;
from Container
Parameters subtab of the
Operation Parameters
tab)
OD
User-defined Freq
Container-
Related/Batch
Any
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Ncy (Containers/site-yr;
from Container
Parameters subtab of the
Operation Parameters
tab)
Nby
OD
User-defined Freq
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab. All default and non-default options for Freq are available for both Output 1
and Output 2.
Key Rationale for Model
The model was developed using Fick's second law of diffusion. Model results were tested
against experimental results of a study on evaporation rates for 15 compounds studied at different air
velocities and temperatures in a test chamber. The experimental data confirmed the utility and accuracy
of the model equation.
Reference
Chemical Engineering Branch Manual for the Preparation of Engineering Assessments,
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991.
(Equation 4-24 and Appendix K)
180
-------
ChemSTEER User Guide - Updated May 2015
Fehrenbacher, M.C. and Hummel, A. A. "Evaluation of the Mass Balance Model Used by the
References Environmental Protection Agency for Estimating Inhalation Exposure to New
Chemical Substances". American Industrial Hygiene Association Journal. June 1996. 57: 526-536.
Model Description
This model estimates releases of a cooling tower additive chemical as a result of windage losses
of the recirculating fluid (e.g., water). This model assumes that 0.1 percent of the cooling tower's
recirculation rate is lost due to windage.
NOTE: This model is a default model for estimating releases to air from the Recirculating Water-
Cooling Tower Additives source/ activity. This model may not be used for any other source/ activity in
ChemSTEER.
Potential Media of Release
Air, Incineration, Landfill and/or Water (default: 100% release to air)
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Cooling Tower Windage Loss Model default values for each of the input
parameters are summarized in Table A-5.
181
-------
ChemSTEER User Guide - Updated May 2015
Table A-5. Input Parameters and Default Values for the EPA/OPPT Cooling Tower Windage Loss Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an
amount of the chemical that is
estimated to be released
Value of LFw from Mass Balance subtab Daily
Mass of Chemical Used (DMUchem) screen;
ChemSteer default for LFw is 0.001
dimensionless
Amt
The amount of chemical to which
a loss fraction is applied
Value of DRRchem from Mass Balance subtab
Daily Mass of Chemical Used (DMUchem)
screen
kg/site-day
Freq
The frequency of release of the
chemical
OD
(from Mass Balance Parameters subtab of
Operation Parameters tab)
day/site-year
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
DR
Total daily release rate of tower
blowdown
Calculated from model equation
kg/site-day
AR
Total annual release rate of
tower blowdown
Calculated from model equation
kg/year (all
sites)
You may not change any parameter from Table A-5.
Default Parameter Value Switch Settings and Results Characterization:
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterizations for either Output 1 or Output 2 results are What-if.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Cooling Tower Windage Loss Model; up to 0.1% of the tower recirculation
rate"
Key Rationale for Model
Windage losses are a function of the mist eliminator design and generally range from less than
0.1% up to 0.2% of the tower's recirculation rate. Some cooling tower manufacturers warrant as low as
0.008% for windage losses. In the absence of other information, this model assumes as a default that
0.1% of the tower's recirculation rate.
Reference
Summary Sheet: Recirculating Water-Cooling Tower, No date.
182
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT Cooling Tower Evaporative Loss Model (volatiles)
Model Description
This model estimates releases of a volatile cooling tower additive chemical as a result of
evaporation of the recirculating fluid (e.g., water). This model assumes that a user-specified fraction of
the cooling tower's recirculation rate is lost due to evaporation.
NOTE: This model is a conditional default model for estimating releases to air from the
Recirculating Water-Cooling Tower Additives source/activity when the vapor pressure of the
chemical (VP) from the Chemical tab is above the low end of the range of adjusted vapor
pressure for the operation (AVPlow). If the vapor pressure of the chemical (VP) from the
Chemical tab is below the low end of the range of adjusted vapor pressure for the operation
(AVPlow), this model will NOT appear as a default because evaporative releases to air from the
cooling tower are assumed negligible for non-volatiles. Refer to Operation Parameters Tab
Shared Parameters/Factors Subtabfor more information.
This model may not be used for any other source/activity in ChemSTEER.
Potential Media of Release
Air, Incineration, Landfill and/or Water (default: 100% release to air)
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Cooling Tower Evaporative Loss Model (volatiles) default values for each of the
input parameters are summarized in Table A-6.
Table A-6. Input Parameters and Default Values for the EPA/OPPT Cooling Tower Evaporative Loss
Model (volatiles)
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an
amount of the chemical that is
estimated to be released
Value of LFe from Mass Balance subtab Daily
Mass of Chemical Used (DMUchem) screen;
ChemSTEER default for LFw is 0
dimensionless
Amt
The amount of chemical to
which a loss fraction is applied
Value of DRRchem from Mass Balance subtab
Daily Mass of Chemical Used (DMUchem)
screen ChemSTEER default for DRRchem is
10,900
kg/site-day
Freq
The frequency of release of the
OD
day/site-year
183
-------
ChemSTEER User Guide - Updated May 2015
chemical
(from Mass Balance Parameters subtab of
Operation Parameters tab)
|
pis
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s) 1
| DR
Total daily release rate of tower
blowdown
Calculated from model equation
kg/site-day I
|ar
Total annual release rate of
tower blowdown
Calculated from model equation
kg/year (all
sites)
You may not change any parameter from Table A-6. If the assessed chemical has significant
volatility and you determine that a non-zero volatility is appropriate, you should change the value of LFe
in Mass Balance subtab Daily Mass of Chemical Used (DMUchem) screen.
Default Parameter Value Switch Settings and Results Characterization:
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterizations for either Output 1 or Output 2 results are What-if.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Cooling Tower Evaporative Loss Model (volatiles); user-specified fraction of
the tower recirculation rate"
Key Rationale for Model
Evaporative losses typically range from 0.5 to 3 percent of the cooling tower's capacity. If the
component within the evaporating fluid is non-volatile, the losses of that component to evaporation are
expected to be negligible. ChemSTEER defaults to a zero loss rate regardless of volatility. There is no
method for determining the relationship between volatility and evaporative loss. If the assessed
chemical has significant volatility, the user should make a judgment as to whether a non-zero volatility is
appropriate.
Reference
Summary Sheet: Recirculating Water-Cooling Tower, No date.
Model Description
User-defined vapor generation rate and associated parameters.
184
-------
ChemSTEER User Guide - Updated May 2015
Sources/Activities That Use This Model as a Default
The User-Defined Vapor Generation Model is the default for calculating releases of a volatile
chemical to air for the Vapor Releases from Open Liquid Surfaces.
Other Sources/Activities
The User-Defined Vapor Generation Rate Model may also be an appropriate means to calculate
volatile releases of the chemical from the following sources/activities:
• All sources/activities for Cleaning Liquid Residuals from Transport Containers/Vessels
• All sources/activities for Equipment Cleaning Losses of Liquids
• All sources/activities for Loading Liquids into Transport Containers/Vessels
• All sources/activities for Unloading Liquids from Transport Containers/Vessels
• All Generic Coating Applications sources/activities
• All Automobile Spray Coating sources/activities
• Miscellaneous Sources/Activities Related to Liquid Processing
• Vapor Releases from Open Liquid Surfaces
Unit Operations and Processes:
• Aqueous Wash of Organic Mass
• Distillation Column Bottoms Disposal
• Filter Media Changeout
• Liquid/Liquid Extraction Solvent Disposal
Scrubber Releases
Potential Media of Release
Air, Water, Incineration, and/ or Landfill (default: 100% of release to air)
Equations
For daily releases:
DR (kg/site-day) = (G x 3600 x OHa) / 1000
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
185
-------
ChemSTEER User Guide - Updated May 2015
The User-Defined Vapor Generation Rate Model default values for each of the input parameters
are summarized in Table A-7.
Table A-7. Input Parameters for the User-Defined Vapor Generation Rate Model
Parameter
Description
Default Value(s)
Units
G
Vapor generation rate
User-defined G
g/s
OHa
Operating hours per site-day for
the activity
Defaults specified in Table A-7a
hours/site-day
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
Freq
The frequency of release of the
chemical
Default specified in Table A-7b
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
You may elect to change any parameter from Table A-7 except the model estimates DR and AR.
Clicking the Type column for each changeable parameter other than G and Freq contains only two
options: ChemSTEER defaults from Table A-7 and User-defined. You must enter a value for G in this
release model. The default value of OHa is dependent upon the selected source/activity. These
conditional default values are summarized in Table A-7a. The conditional default and non-default
options for Freq are presented in Table A-7b below. Be sure to read the ChemSTEER Estimation Methods
and Models topic for more information about changing model parameters.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Output 1
Default Characterization of Output 2 Results: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"User-defined Vapor Generation Rate Model"
186
-------
ChemSTEER User Guide - Updated May 2015
Table A-7a. Default Values for Operation Hours (OHa) for the User-Defined Vapor Generation Rate
Model
Source/Activity Type
Default OHa1
(hrs/site-day)
Container-Related
OHa
(from Container Parameters subtab of
the Operation Parameters tab)
Equipment Cleaning Losses of Liquids from Multiple Vessels
4
Equipment Cleaning Losses of Liquids from a Single, Large Vessel
1
Equipment Cleaning Losses of Liquids from a Single, Small Vessel
0.5
Sampling Liquid Product, Sampling Liquid Raw Material, Sampling
Liquids
1
All other sources/activities not covered by above for continuous
operations
24
All other sources/activities not covered by above for batch operations
Less of 24 or (HB x Nbd)
(from Mass Balance subtab of the
Operations Parameters tab)
1. You may select the conditional default OHa (shown above) or enter a user-defined OHa for either Output 1 or
Output 2 for all sources/activities. The conditional default OHa values were adopted as a policy decision in 2002.
187
-------
ChemSTEER User Guide - Updated May 2015
Table A-7b. Conditional Default Values for Freq for the User-Defined Vapor Generation Rate Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options for
Freq*
Container-
Related/Continuous
Not Applicable
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Ncy (Containers/site-yr;
from Container
Parameters subtab of the
Operation Parameters
tab)
OD
User-defined Freq
Container-
Related/Batch
Any
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Ncy (Containers/site-yr;
from Container
Parameters subtab of the
Operation Parameters
tab)
Nby
OD
User-defined Freq
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
Key Rationale for Model
NA
Reference
NA
Models for Calculating Releases to Other Media
EPA/OPPT Bulk Transport Residual Model
Model Description
188
-------
ChemSTEER User Guide - Updated May 2015
EPA assumes that liquids are pumped from bulk transport containers and that up to 0.2% (a
central tendency of 0.07%) of the liquid originally in the bulk container remains as residual after
unloading.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Bulk Transport Residual Model as the default
non-air releases model:
• Cleaning Liquid Residuals from Totes Used to Transport the Raw Material/Product (see
Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Tank Trucks Used to Transport the Raw Material/Product
(see Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Rail Cars Used to Transport the Raw Material/Product
(see Cleaning Liquid Residuals from Transport Containers/Vessels)
Other Sources/Activities
The EPA/OPPT Bulk Transport Residual Model may be an appropriate alternative to the default
non-air release model for the following sources/activities:
• Cleaning Liquid Residuals from Containers Used to Transport the Raw Material/Product
(see Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Storage/Transport Vessels (User-defined) (see Cleaning
Liquid Residuals from Transport Containers/Vessels)
Potential Media of Release
Water, Incineration, and/ or Landfill (default: 100% of release to water)
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Bulk Transport Residual Model default values for each of the input parameters
are summarized in Table A-8.
189
-------
ChemSTEER User Guide - Updated May 2015
Table A-8. Input Parameters and Default Values for the EPA/OPPT Bulk Transport Residual Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an amount of the
chemical that is estimated to be released
Output 1:
Default: 0.0007 (Central Tendency)
Non-default option: 0.002 (High End)
dimensionless
Output 2:
Default: 0.002 (High End)
Non-default option: 0.0007 (Central
Tendency)
Amt
The amount of chemical to which a loss
fraction is applied
Defaults specified in Table A-8a
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of Operation Parameters tab)
site(s)
Freq
The frequency of release of the chemical
Default specified in Table A-8b
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
You may elect to change any parameter from Table A-8 except the model estimates DR and AR.
Clicking the Type column for each changeable parameter other than LF, Amt and Freq contains only two
options: ChemSTEER defaults from Table A-8 and User-defined. The conditional default and non-default
options for Amt and Freq are presented in the tables below. Be sure to read the ChemSTEER Estimation
Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameter, LF, to be anything other than one of the
defaults shown above. If you wish to model releases from bulk container residues using your own loss
fraction, choose the User-Defined Loss Rate Model.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Settings for either Output 1 or Output 2 results are based on which LF is selected for the
corresponding output:
• Results using the high end loss fraction are characterized as High End by default.
• Results using the central tendency loss fraction are characterized as Central Tendency by
default.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Bulk Transport Residual Model, CEB standard 0.2% residual"
190
-------
ChemSTEER User Guide - Updated May 2015
Table A-8a. Conditional Default Values for Amt for the EPA/OPPT Bulk Transport Residual Model
Source/Activity
Type/Operation
Mode
Batch Condition
Operation Type
Conditional Amt
Default (kg/site-day)
Non-default Options
for Amt*
Container-Related /
Continuous
Not Applicable
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
DMIchem
DMOchem
User-defined Amt
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
Container-Related /
Batch
Any
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
BMIchem
BMOchem
BMIchem x Ls
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
BMIchem x Nbd
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Not Container-
Related /
Continuous
Not Applicable
Manufacturing
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMIchem
User-defined Amt
Processing
Use
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMOchem
User-defined Amt
Not Container-
Related / Batch
Number of batches
per day
(Nbd)< 1
(from Mass Balance
Parameters subtab
Manufacturing
BMOchem (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
191
-------
ChemSTEER User Guide - Updated May 2015
of the Operation
Parameters tab)
Number of batches
per day
(Nbd)> 1
(from Mass Balance
Parameters subtab
of the Operation
Parameters tab)
User-defined Amt
Processing
Use
BMIchem (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
User-defined Amt
Manufacturing
BMOchem x Nbd
(kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIchem
BMOchem
BMIchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Processing BMIchem x Nbd
Use (kg/site-day)
(from the Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIchem
BMOchem
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
192
-------
ChemSTEER User Guide - Updated May 2015
Table A-8b. Conditional Default Values for Freq for the EPA/OPPT Bulk Transport Residual Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Container-
Related/Batch
Any
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
193
-------
ChemSTEER User Guide - Updated May 2015
Key Rationale for Model
The two tenths and seven hundredths of one percent loss are high-end and central tendency
values, respectively, in a range of values from an EPA-sponsored study of liquid residuals in bottom-
unloaded, gravity drain tanks.
References
US EPA Memo entitled Standard Assumptions for PMN Assessments from the Chemical
Engineering Branch Quality Panel to Chemical Engineering Branch Staff and Management.
10/92.
PEI Associates for US EPA/OTS. Releases During Cleaning of Equipment. July 1988.
Model Description
EPA assumes that liquids are pumped from drums and that up to 3% (a central tendency of
2.5%) of the liquid originally in the drums remains as residual after unloading. Alternative assumptions
include 0.6% high end and 0.3% central tendency when pouring liquids from drums.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Drum Residual Model as the default non-air
release model:
• Cleaning Liquid Residuals from Drums Used to Transport the Raw Material/Product (see
Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Containers Used to Transport the Raw Material/Product
(see Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Storage/Transport Vessels (User-defined) (see Cleaning
Liquid Residuals from Transport Containers/Vessels)
Other Sources/Activities
The EPA/OPPT Drum Residual Model may be an appropriate alternative to the default non-air
release model for the following sources/activities:
• Cleaning Liquid Residuals from Bottles Used to Transport the Raw Material/Product (see
Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Small Containers Used to Transport the Raw
Material/Product (see Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Totes Used to Transport the Raw Material/Product (see
Cleaning Liquid Residuals from Transport Containers/Vessels)
Potential Media of Release
194
-------
ChemSTEER User Guide - Updated May 2015
Water, Incineration, and/ or Landfill (default: 100% of release to water)
NOTE: a 1994 policy decision was issued to account for uncertainties in media of releases, and
many residual releases are assumed to be released to water as a default. This 1994 decision
supersedes the default medium of release that is listed in the 1992 reference memorandum.
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Drum Residual Model default values for each of the input parameters are
summarized in Table A-9.
Table A-9. Input Parameters and Default Values for the EPA/OPPT Drum Residual Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an
amount of the chemical that is
estimated to be released
Output 1:
Default: 0.025 (Central Tendency)
Non-default option: 0.03 (High End)*; 0.006
(High End for pouring); and 0.003 (Central
Tendency for pouring)
dimensionless
Output 2:
Default: 0.03 (High End for Dumping)*
Non-default option: 0.025 (Central
Tendency); 0.006 (High End for pouring); and
0.003 (Central Tendency for pouring)
Amt
The amount of chemical to which
a loss fraction is applied
Defaults specified in Table A-9a
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
Freq
The frequency of release of the
chemical
Default specified in Table A-9b
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
*The high end loss fraction (LF) was developed as an internal policy decision in 2002. The 1992 EPA memorandum
reference document contains the previous default of 4 percent (high end for pumping); however, this was
superseded by this internal policy decision.
You may elect to change any parameter from Table A-9 except the model estimates DR and AR.
Clicking the Type column for each changeable parameter other than LF, Amt and Freq contains only two
195
-------
ChemSTEER User Guide - Updated May 2015
options: ChemSTEER defaults from Table A-9 and User-defined. The conditional default and non-default
options for Amt and Freq are presented in the tables below. Be sure to read the ChemSTEER Estimation
Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameter, LF, to be anything other than one of the
defaults shown above. If you wish to model releases from drum residues using your own loss fraction,
choose the User-Defined Loss Rate Model.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterizations for either Output 1 or Output 2 results are based on which LF is
selected for the corresponding output:
• Results using the high end loss fractions (i.e., 0.03 for pumping or 0.006 for pouring) are
characterized as High End by default.
• Results using the central tendency loss fractions (i.e., 0.025 for pumping or 0.003 for
pouring) are characterized as Central Tendency by default.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Drum Residual Model, CEB standard 3% residual"
196
-------
ChemSTEER User Guide - Updated May 2015
Table A-9a. Conditional Default Values for Amt for the EPA/OPPT Drum Residual Model
Source/Activity
Type/Operation
Mode
Batch Condition
Operation Type
Conditional Amt Default
(kg/site-day)
Non-default Options
for Amt*
Container-Related /
Continuous
Not Applicable
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of the
Operation Parameters
tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
DMIchem
DMOchem
User-defined Amt
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of the
Operation Parameters
tab)
Container-Related /
Batch
Any
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of the
Operation Parameters
tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
BMIchem
BMOchem
BMIchem x Ls
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of the
Operation Parameters
tab)
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
BMIchem x Nbd
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Not Container-
Related / Continuous
Not Applicable
Manufacturing
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMIchem
User-defined Amt
Processing
Use
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMOchem
User-defined Amt
Not Container-
Related / Batch
Number of batches
per day
(Nbd)< 1
(from Mass Balance
Parameters subtab of
Manufacturing
BMOchem (kg/line-bt)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMIchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
197
-------
ChemSTEER User Guide - Updated May 2015
the Operation
User-defined Amt
Parameters tab)
Processing
BMIchem (kg/line-bt)
BMIchem
Use
(from Mass Balance
BMIchem x Ls
Parameters subtab of the
(kg/site-bt)
Operation Parameters
BMOchem x Ls
tab)
(kg/site-bt)
User-defined Amt
Number of batches
Manufacturing
BMOchem x Nbd
BMIchem
per day
(kg/site-day)
BMOchem
(Nbd)> 1
BMIchem x Nbd
(from Mass Balance
(from Mass Balance
BMIchem x Nbd/Ls
Parameters subtab of
Parameters subtab of the
(kg/line-day)
the Operation
Operation Parameters
BMOchem x Nbd/Ls
Parameters tab)
tab)
(kg/line-day)
User-defined Amt
Processing
BMIchem x Nbd
BMIchem
Use
(kg/site-day)
BMOchem
(from the Mass Balance BMOchem x Nbd
Parameters subtab of the BMIchem x Nbd/Ls
Operation Parameters (kg/line-day)
tab) BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release
Model Information screen in the Releases tab.
198
-------
ChemSTEER User Guide - Updated May 2015
Table A-9b. Conditional Default Values for Freq for the EPA/OPPT Drum Residual Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Container-
Related/Batch
Any
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
Key Rationale for Model
The three-percent loss is roughly equivalent to a one-inch heel in a standard 55-gallon drum.
This is the basis for the high-end default estimate for pumping. Alternative, less conservative estimates
obtained when liquids are poured from drums include 0.6% (high-end) and 0.3% (central
tendency/mean).
References
199
-------
ChemSTEER User Guide - Updated May 2015
US EPA Memo entitled Standard Assumptions for PMN Assessments from the Chemical
Engineering Branch Quality Panel to Chemical Engineering Branch Staff and Management.
10/92.
PEI Associates for US EPA/OTS. Releases During Cleaning of Equipment. July 1988.
Model Description
EPA assumes that 2% of the material being manufactured or processed remains as residual in
the vessels after it is drained (via pump) following the operation.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Multiple Process Vessel Residual Model as
the default non-air release model:
• Equipment Cleaning Losses of Liquids from Multiple Vessels (see Equipment Cleaning
Losses of Liquids)
Other Sources/Activities
The EPA/OPPT Multiple Process Vessel Residual Model may be an appropriate alternative to the
default non-air release model for the following sources/activities:
• Equipment Cleaning Losses of Liquids from a Single, Small/Large Vessel (see Equipment
Cleaning Losses of Liquids)
Potential Media of Release
Water, Incineration, and/or Landfill (default: 100% of release to water)
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Multiple Process Vessel Residual Model default values for each of the input
parameters are summarized in Table A-10.
200
-------
ChemSTEER User Guide - Updated May 2015
Table A-10. Input Parameters and Default Values for the EPA/OPPT Multiple Process Vessel Residual
Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an amount of the
chemical that is estimated to be released
0.02 (conservative)
dimensionless
Amt
The amount of chemical to which a loss
fraction is applied
Defaults specified in Table A-10a
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of Operation Parameters tab)
site(s)
Freq
The frequency of release of the chemical
Default specified in Table A-10b
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
You may elect to change any parameter from Table A-10 except the model estimates DR and AR.
Clicking the Type column for each changeable parameter other than LF, Amt and Freq contains only two
options: ChemSTEER defaults from Table A-10 and User-defined. The conditional default and non-
default options for Amt and Freq are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameter, LF, to be anything other than one of the
defaults shown above. If you wish to model releases from multiple process vessel residues using your
own loss fraction, choose the User-Defined Loss Rate Model.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Conservative
Default Characterization of Output 2 Results: Conservative
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Multiple Process Vessel Residual Model, CEB standard 2% residual"
201
-------
ChemSTEER User Guide - Updated May 2015
Table A-lOa. Conditional Default Values for Amt for the EPA/OPPT Multiple Process Vessel Residual
Model
Source/Activity
Type/Operation
Mode
Batch Condition
Operation Type
Conditional Amt Default
(kg/site-day)
Non-default Options
for Amt*
Container-Related /
Continuous
Not Applicable
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of the
Operation Parameters
tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
DMIchem
DMOchem
User-defined Amt
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of the
Operation Parameters
tab)
Container-Related /
Batch
Any
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of the
Operation Parameters
tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
BMIchem
BMOchem
BMIchem x Ls
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of the
Operation Parameters
tab)
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
BMIchem x Nbd
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Not Container-
Related / Continuous
Not Applicable
Manufacturing
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMIchem
User-defined Amt
Processing
Use
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMOchem
User-defined Amt
Not Container-
Related / Batch
Number of batches
per day
(Nbd)< 1
(from Mass Balance
Manufacturing
BMOchem (kg/line-bt)
(from Mass Balance
Parameters subtab of the
Operation Parameters
BMIchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
202
-------
ChemSTEER User Guide - Updated May 2015
Parameters subtab of
tab)
(kg/site-bt)
the Operation
User-defined Amt
Parameters tab) Processing ^
BMIchem (kg/line-bt)
BMIchem
Use
(from Mass Balance
BMIchem x Ls
Parameters subtab of the
(kg/site-bt)
Operation Parameters
BMOchem x Ls
tab)
(kg/site-bt)
User-defined Amt
Number of batches Manufacturing
BMOchem x Nbd
BMIchem
per day
(kg/site-day)
BMOchem
(Nbd)> 1
BMIchem x Nbd
(from Mass Balance
(from Mass Balance
BMIchem x Nbd/Ls
Parameters subtab of
Parameters subtab of the
(kg/line-day)
the Operation
Operation Parameters
BMOchem x Nbd/Ls
Parameters tab)
tab)
(kg/line-day)
User-defined Amt
Processing
BMIchem x Nbd
BMIchem
Use
(kg/site-day)
BMOchem
(from the Mass Balance
BMOchem x Nbd
Parameters subtab of the
BMIchem x Nbd/Ls
Operation Parameters
(kg/line-day)
tab)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
203
-------
ChemSTEER User Guide - Updated May 2015
Table A-lOb. Conditional Default Values for Freq for the EPA/OPPT Multiple Process Vessel Residual
Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Container-
Related/Batch
Any
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
Key Rationale for Model
Two percent of mass throughput based on the information and data in the July 1988 reference;
the panel of chemical engineers with a variety of industrial experience considered this percentage to be
a generally conservative estimate.
References
204
-------
ChemSTEER User Guide - Updated May 2015
US EPA Memo entitled Standard Assumptions for PMN Assessments from the Chemical
Engineering Branch Quality Panel to Chemical Engineering Branch Staff and Management.
10/92.
PEI Associates for US EPA/OTS. Releases During Cleaning of Equipment. July 1988.
Model Description
EPA assumes that up to 1% of the material being manufactured or processed remains as residual
in the vessel after it is drained (via pump) following the operation. Alternative assumptions include 0.2%
high end and 0.07% central tendency for gravity-drained vessels.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Single Process Vessel Residual Model as the
default non-air release model:
• Equipment Cleaning Losses of Liquids from a Single, Small Vessel (see Equipment
Cleaning Losses of Liquids)
• Equipment Cleaning Losses of Liquids from a Single, Large Vessel (see Equipment
Cleaning Losses of Liquids)
Other Sources/Activities
The EPA/OPPT Single Process Vessel Residual Model may be an appropriate alternative to the
default non-air release model for the following sources/activities:
• Equipment Cleaning Losses of Liquids from Multiple Vessels (see Equipment Cleaning
Losses of Liquids)
Potential Media of Release
Water, Incineration, and/or Landfill (default: 100% of release to water)
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
205
-------
ChemSTEER User Guide - Updated May 2015
The EPA/OPPT Single Process Vessel Residual Model default values for each of the input
parameters are summarized in Table A-ll.
Table A-ll. Input Parameters and Default Values for the EPA/OPPT Single Process Vessel Residual
Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an amount
of the chemical that is estimated to
be released
Output 1:
Default: 0.002 (High End to Bounding for
gravity drain)
Non-default option: 0.01 (Conservative);
and 0.0007 (Central Tendency for gravity
drain)
dimensionless
Output 2:
Default: 0.01 (Conservative for Dumping)
Non-default option: 0.002 (High End to
Bounding ); and 0.0007 (Central Tendency
for gravity drain)
Amt
The amount of chemical to which a
loss fraction is applied
Defaults specified in Table A-lla
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
Freq
The frequency of release of the
chemical
Default specified in Table A-llb
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
You may elect to change any parameter from Table A-ll except the model estimates DR and AR.
Clicking the Type column for each changeable parameter other than LF, Amt and Freq contains only two
options: ChemSTEER defaults from Table A-ll and User-defined. The conditional default and non-
default options for Amt and Freq are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameter, LF, to be anything other than one of the
defaults shown above. If you wish to model releases from a single process vessel residue using your own
loss fraction, choose the User-Defined Loss Rate Model.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterizations for either Output 1 or Output 2 results are based on which LF
is selected for the corresponding output:
• Results using the conservative loss fraction for pumping (i.e., 0.01) are characterized
as Conservative by default.
206
-------
ChemSTEER User Guide - Updated May 2015
• Results using the high end loss fraction for gravity draining (i.e., 0.002) are
characterized as High End to Bounding by default.
• Results using the central tendency loss fraction for gravity draining (i.e., 0.0007) are
characterized as Central Tendency by default.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Single Vessel Residual Model, CEB standard 1% residual"
207
-------
ChemSTEER User Guide - Updated May 2015
Table A-lla. Conditional Default Values for Amt for the EPA/OPPT Single Process Vessel Residual
Model
Source/Activity
Type/Operation
Mode
Batch Condition
Operation Type
Conditional Amt Default
(kg/site-day)
Non-default Options
for Amt*
Container-Related /
Continuous
Not Applicable
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
DMIchem
DMOchem
User-defined Amt
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
Container-Related /
Batch
Any
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
BMIchem
BMOchem
BMIchem x Ls
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
BMIchem x Nbd
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Not Container-
Related /
Continuous
Not Applicable
Manufacturing
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMIchem
User-defined Amt
Processing
Use
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMOchem
User-defined Amt
Not Container-
Related / Batch
Number of batches
per day
(Nbd)< 1
(from Mass Balance
Manufacturing
BMOchem (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
BMIchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
208
-------
ChemSTEER User Guide - Updated May 2015
Parameters subtab
of the Operation
Parameters tab)
Number of batches
per day
(Nbd)> 1
(from Mass Balance
Parameters subtab
of the Operation
Parameters tab)
Parameters tab)
(kg/site-bt)
User-defined Amt
Processing
BMIchem (kg/line-bt)
BMIchem
Use
(from Mass Balance
BMIchem x Ls
Parameters subtab of
(kg/site-bt)
the Operation
BMOchem x Ls
Parameters tab)
(kg/site-bt)
User-defined Amt
Manufacturing
BMOchem x Nbd
BMIchem
(kg/site-day)
BMOchem
BMIchem x Nbd
(from Mass Balance
BMIchem x Nbd/Ls
Parameters subtab of
(kg/line-day)
the Operation
BMOchem x Nbd/Ls
Parameters tab)
(kg/line-day)
User-defined Amt
Processing
BMIchem x Nbd
BMIchem
Use
(kg/site-day)
BMOchem
(from the Mass Balance
BMOchem x Nbd
Parameters subtab of
BMIchem x Nbd/Ls
the Operation
(kg/line-day)
Parameters tab)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
209
-------
ChemSTEER User Guide - Updated May 2015
Table A-llb. Conditional Default Values for Freq for the EPA/OPPT Single Process Vessel Residual
Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Container-
Related/Batch
Any
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
Key Rationale for Model
One percent of mass throughput based on the information and data (for pumping) in the July
1988 reference; the panel of chemical engineers with a variety of industrial experience considered this
percentage to be a generally conservative estimate. Alternative, less conservative estimates obtained
for gravity-drained vessels include 0.2% (high-end to bounding) and 0.07% (central tendency/mean).
210
-------
ChemSTEER User Guide - Updated May 2015
References
US EPA Memo entitled Standard Assumptions for PMN Assessments from the Chemical
Engineering Branch Quality Panel to Chemical Engineering Branch Staff and Management.
10/92.
PEI Associates for US EPA/OTS. Releases During Cleaning of Equipment. July 1988.
Model Description
EPA assumes that liquids are poured from small shipping containers and that up to 0.6% (a
central tendency of 0.3%) of the liquid originally in the container remains as residual after unloading.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Small Container Residual Model as the
default for calculating non-releases:
• Cleaning Liquid Residuals from Bottles Used to Transport the Raw Material/Product (see
Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Small Containers Used to Transport the Raw
Material/Product (see Cleaning Liquid Residuals from Transport Containers/Vessels)
Other Sources/Activities
The EPA/OPPT Small Container Residual Model may be an appropriate alternative to the default
non-air release model for the following sources/activities:
• Cleaning Liquid Residuals from Containers Used to Transport the Raw Material/Product
(see Cleaning Liquid Residuals from Transport Containers/Vessels)
• Cleaning Liquid Residuals from Storage/Transport Vessels (User-defined) (see Cleaning
Liquid Residuals from Transport Containers/Vessels)
Potential Media of Release
Water, Incineration, and/or Landfill (default: 100% of release to water)
NOTE: a 1994 policy decision was issued to account for uncertainties in media of releases, and
many residual releases are assumed to be released to water as a default. This 1994 decision
supersedes the default medium of release that is listed in the 1992 reference memorandum.
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
211
-------
ChemSTEER User Guide - Updated May 2015
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Small Container Residual Model default values for each of the input parameters
are summarized in Table A-12.
Table A-12. Input Parameters and Default Values for the EPA/OPPT Small Container Residual Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an amount of the
chemical that is estimated to be released
Output 1:
Default: 0.003 (Central Tendency)
Non-default option: 0.006 (High End)
dimensionless
Output 2:
Default: 0.006 (High End)
Non-default option: 0.003 (Central
Tendency)
Amt
The amount of chemical to which a loss
fraction is applied
Defaults specified in Table A-12a
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of Operation Parameters tab)
site(s)
Freq
The frequency of release of the chemical
Default specified in Table A-12b
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
You may elect to change any parameter from Table A-12 except the model estimates DR and AR.
Clicking the Type column for each changeable parameter other than LF, Amt and Freq contains only two
options: ChemSTEER defaults from Table A-12 and User-defined. The conditional default and non-
default options for Amt and Freq are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameter, LF, to be anything other than one of the
defaults shown above. If you wish to model releases from small container residues using your own loss
fraction, choose the User-Defined Loss Rate Model.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterizations for either Output 1 or Output 2 results are based on which LF
is selected for the corresponding output:
• Results using the high end loss fraction (i.e., 0.006) are characterized as High End by
default.
212
-------
ChemSTEER User Guide - Updated May 2015
• Results using the central tendency loss fraction (i.e., 0.003) are characterized as
Central Tendency by default.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Small Container Residual Model, CEB standard 0.6% residual"
213
-------
ChemSTEER User Guide - Updated May 2015
Table A-12a. Conditional Default Values for Amt for the EPA/OPPT Small Container Residual Model
Source/Activity
Type/Operation
Mode
Batch Condition
Operation Type
Conditional Amt Default
(kg/site-day)
Non-default Options
for Amt*
Container-Related /
Continuous
Not Applicable
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
DMIchem
DMOchem
User-defined Amt
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
Container-Related /
Batch
Any
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
BMIchem
BMOchem
BMIchem x Ls
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
BMIchem x Nbd
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Not Container-
Related /
Continuous
Not Applicable
Manufacturing
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMIchem
User-defined Amt
Processing
Use
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMOchem
User-defined Amt
Not Container-
Related / Batch
Number of batches
per day
(Nbd)< 1
(from Mass Balance
Parameters subtab
Manufacturing
BMOchem (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
214
-------
ChemSTEER User Guide - Updated May 2015
of the Operation
Parameters tab)
Number of batches
per day
(Nbd)> 1
(from Mass Balance
Parameters subtab
of the Operation
Parameters tab)
User-defined Amt
Processing
Use
BMIchem (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
User-defined Amt
Manufacturing
BMOchem x Nbd
(kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIchem
BMOchem
BMIchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Processing
Use
BMIchem x Nbd
(kg/site-day)
(from the Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIchem
BMOchem
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
215
-------
ChemSTEER User Guide - Updated May 2015
Table A-12b. Conditional Default Values for Freq for the EPA/OPPT Small Container Residual Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Container-
Related/Batch
Any
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
Key Rationale for Model
The six tenths and three tenths of one percent loss are high end and central tendency values,
respectively, in a range of values from an EPA sponsored study residuals in containers from which liquids
have been poured.
References
216
-------
ChemSTEER User Guide - Updated May 2015
US EPA Memo entitled Standard Assumptions for PMN Assessments from the Chemical
Engineering Branch Quality Panel to Chemical Engineering Branch Staff and Management.
10/92.
PEI Associates for US EPA/OTS. Releases During Cleaning of Equipment. July 1988.
Model Description
EPA assumes that solids are transferred from shipping containers and that up to 1% (by weight)
of the solids originally in the container remains as residual after unloading.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Solid Residuals in Transport Containers
Model as the default for calculating non-air releases:
• All sources/activities for Cleaning Solid Residuals from Transport Containers/Vessels
• Equipment Cleaning Losses of Solids from Process Vessels
This model is not used as an alternative release model for any other sources/activities.
Potential Media of Release
Water, Incineration, and/or Landfill (default: 100% of release to water)
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Solid Residual in Transport Containers Model default values for each of the input
parameters are summarized in Table A-13.
217
-------
ChemSTEER User Guide - Updated May 2015
Table A-13. Input Parameters and Default Values for the EPA/OPPT Solid Residuals in Transport
Containers Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an amount of the
chemical that is estimated to be released
0.01 (not characterized)
dimensionless
Amt
The amount of chemical to which a loss
fraction is applied
Defaults specified in Table A-13a
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of Operation Parameters tab)
site(s)
Freq
The frequency of release of the chemical
Default specified in Table A-13b
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
You may elect to change any parameter from Table A-13 except the model estimates DR and
AR. Clicking the Type column for each changeable parameter other than LF, Amt and Freq contains only
two options: ChemSTEER defaults from Table A-13 and User-defined. The conditional default and non-
default options for Amt and Freq are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameter, LF, to be anything other than one of the
defaults shown above. If you wish to model releases of container solid residues using your own loss
fraction, choose the User-Defined Loss Rate Model.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Output 1
Default Characterization of Output 2 Results: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Solid Residuals in Transport Containers Model, CEB standard 1% residual"
218
-------
ChemSTEER User Guide - Updated May 2015
Table A-13a. Conditional Default Values for Amt for the EPA/OPPT Solid Residuals in Transport
Containers Model
Source/Activity
Type/Operation
Mode
Batch Condition
Operation Type
Conditional Amt
Default (kg/site-day)
Non-default Options
for Amt*
Container-Related /
Continuous
Not Applicable
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
DMIchem
DMOchem
User-defined Amt
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
Container-Related /
Batch
Any
Any
For Ned > 1:
MCi x Yi x Ned
(kg chemical/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (kg
material/container)
MCi x Yi (for Ned > 1
only)
BMIchem
BMOchem
BMIchem x Ls
For Ned < 1:
MCi x Yi
(kg chemical/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
(kg/site-bt)
BMOchem x Ls
(kg/site-bt)
BMIchem x Nbd
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Not Container-
Related /
Continuous
Not Applicable
Manufacturing
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMIchem
User-defined Amt
Processing
Use
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMOchem
User-defined Amt
Not Container-
Related / Batch
Number of batches
per day
(Nbd)< 1
(from Mass Balance
Manufacturing
BMOchem (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
BMIchem
BMIchem x Ls
(kg/site-bt)
BMOchem x Ls
219
-------
ChemSTEER User Guide - Updated May 2015
Parameters subtab
of the Operation
Parameters tab)
Number of batches
per day
(Nbd)> 1
(from Mass Balance
Parameters subtab
of the Operation
Parameters tab)
Parameters tab)
(kg/site-bt)
User-defined Amt
Processing
BMIchem (kg/line-bt)
BMIchem
Use
(from Mass Balance
BMIchem x Ls
Parameters subtab of
(kg/site-bt)
the Operation
BMOchem x Ls
Parameters tab)
(kg/site-bt)
User-defined Amt
Manufacturing
BMOchem x Nbd
BMIchem
(kg/site-day)
BMOchem
BMIchem x Nbd
(from Mass Balance
BMIchem x Nbd/Ls
Parameters subtab of
(kg/line-day)
the Operation
BMOchem x Nbd/Ls
Parameters tab)
(kg/line-day)
User-defined Amt
Processing
BMIchem x Nbd
BMIchem
Use
(kg/site-day)
BMOchem
(from the Mass Balance
BMOchem x Nbd
Parameters subtab of
BMIchem x Nbd/Ls
the Operation
(kg/line-day)
Parameters tab)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
220
-------
ChemSTEER User Guide - Updated May 2015
Table A-13b. Conditional Default Values for Freq for the EPA/OPPT Solid Residuals in Transport
Containers Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Container-
Related/Batch
Any
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
Key Rationale for Model
The one percent loss is a value based on an extrapolation of a range of values from an EPA
sponsored study of residuals in containers from which liquids have been poured
References
221
-------
ChemSTEER User Guide - Updated May 2015
US EPA Memo entitled Standard Assumptions for PMN Assessments from the Chemical
Engineering Branch Quality Panel to Chemical Engineering Branch Staff and Management.
10/92.
PEI Associates for US EPA/OTS. Releases During Cleaning of Equipment. July 1988.
Model Description
EPA assumes that water contacted with a mass of material containing the chemical becomes
saturated with the chemical. This water saturated with the chemical is wasted or disposed.
Sources/Activities That Use This Model as a Default
The following sources/activities use EPA/OPPT Water Saturation Loss Model as the default for
calculating non-air releases:
• Aqueous Wash of Organic Mass
EPA/OPPT Water Saturation Loss Model - Other Sources/Activities
The EPA/OPPT Water Saturation Loss Model may be an appropriate alternative to the default
non-air release model for the following sources/activities:
• Miscellaneous Sources/Activities.
Potential Media of Release
Water, Incineration, and/ or Landfill (default: 100% of release to water)
Equations
For daily releases:
DR (kg/site-day) = WSchem x CF x Amt / 1000
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Water Saturation Loss Model default values for each of the input parameters are
summarized in Table A-14.
222
-------
ChemSTEER User Guide - Updated May 2015
Table A-14. Input Parameters and Default Values for the EPA/OPPT Water Saturation Loss Model
Parameter
Description
Default Value(s)
Units
WSchem
Water solubility of the chemical
WSchem
(from chemical tab)
g/L
CF
Correction factor*
1
dimensionless
Amt
An amount of water in which the
chemical reaches saturation
Value based on Table A-14a
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
Freq
The frequency of release of the
chemical
Default specified in Table A-14b
day/site-year
DR
Daily Release rate
Calculated from model equation
kg/site-day
AR
Annual Release rate
Calculated from model equation
kg/year (all
sites)
*A factor that you may adjust to account for: (1) multiples of an amount (Amt) of water (e.g., multiple washings);
(2) a known or estimated correction of the water solubility of the chemical; and/ or (3) other corrections.
You may elect to change any parameter from Table A-14 except the model estimates DR and AR.
Clicking the Type column for each changeable parameter other than Amt and Freq contains only two
options: ChemSTEER defaults from Table A-14 and User-defined. The conditional default and non-
default options for Amt and Freq are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Output 1
Default Characterization of Output 2 Results: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Water Saturation Loss Model"
223
-------
ChemSTEER User Guide - Updated May 2015
Table A-14a. Conditional Default Values for Amt for the EPA/OPPT Water Saturation Loss Model
Source/Activity
Type/Operation
Mode
Batch Condition
Operation Type
Conditional Amt
Default (kg/site-day)
Non-default Options
for Amt*
Container-Related /
Continuous
Not Applicable
Any
For Ned > 1:
MCi x Ned
(kg material/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (for Ned > 1
only)
DMIrm
DMOprod
User-defined Amt
For Ned < 1:
MCi
(kg material/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
Container-Related /
Batch
Any
Any
For Ned > 1:
MCi x Ned
(kg material/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
MCi (for Ned > 1
only)
BMIrm
BMOprod
BMIrmx Ls (kg/site-
bt)
BMOprod x Ls
For Ned < 1:
MCi
(kg material/container)
(from Container
Parameters subtab of
the Operation
Parameters tab)
(kg/site-bt)
BMIrm x Nbd
BMOprod x Nbd
BMIrm x Nbd/Ls
(kg/line-day)
BMOprod x Nbd/Ls
(kg/line-day)
User-defined Amt
Not Container-
Related /
Continuous
Not Applicable
Manufacturing
DMOprod (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMIrm
User-defined Amt
Processing
Use
DMIrm (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMOprod
User-defined Amt
Not Container-
Related / Batch
Number of batches
per day
(Nbd)< 1
(from Mass Balance
Parameters subtab
of the Operation
Manufacturing
BMOprod (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIrm
BMIrm x Ls (kg/site-
bt)
BMOprod x Ls
(kg/site-bt)
User-defined Amt
Parameters tab)
Processing
BMIrm (kg/line-bt)
BMIrm
224
-------
ChemSTEER User Guide - Updated May 2015
Use (from Mass Balance
BMIrm x Ls (kg/site-
Parameters subtab of
bt)
the Operation
BMOprod x Ls
Parameters tab)
(kg/site-bt)
User-defined Amt
Number of batches
Manufacturing | BMOprod x Nbd
BMIrm
per day
(kg/site-day)
BMOprod
(Nbd)> 1
BMIrm x Nbd
(from Mass Balance
(from Mass Balance
BMIrm x Nbd/Ls
Parameters subtab
Parameters subtab of
(kg/line-day)
of the Operation
the Operation
BMOprod x Nbd/Ls
Parameters tab)
Parameters tab)
(kg/line-day)
1
User-defined Amt
Processing BMIrm x Nbd
BMIrm
Use (kg/site-day)
BMOprod
(from the Mass Balance
BMOprod x Nbd
Parameters subtab of
BMIrm x Nbd/Ls
the Operation
(kg/line-day)
Parameters tab)
BMOprod x Nbd/Ls
(kg/line-day)
1
1
User-defined Amt
*Amt (of water) defaults correspond to throughput volumes of materials processed (e.g., if 10,000 kg/day of
product is produced in the operation, the default Amt (amount of water) contacting the batch of material
containing the chemical is also 10,000 kg/day).
**Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
225
-------
ChemSTEER User Guide - Updated May 2015
Table A-14b. Conditional Default Values for Freq for the EPA/OPPT Water Saturation Loss Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Container-
Related/Batch
Any
For Ned > 1:
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
For Ncd< 1:
Ncy (containers/site-yr)
(from Container Parameters
subtab of the Operation
Parameters tab)
Not Container-
Related/Continuous
Not Applicable
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
User-defined Freq
Not Container-
Related/Batch
Number of batches per day
(Nbd) 1)
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
Key Rationale for Model
Water contacted with a mass of material containing the chemical can become partially or fully
saturated with the chemical as the chemical dissolves in the water, or chemical can be entrained in the
water at levels below or above the saturation level. Assuming water saturation allows for a rough
estimation when not enough information is available to make other estimates.
Reference
226
-------
ChemSTEER User Guide - Updated May 2015
NA
Model Description
This model estimates releases of a cooling tower additive chemical as a result of periodic
blowdown of the recirculating fluid (e.g., water). This model assumes that 0.6 percent of the cooling
tower's recirculation rate is discharged during blowdown.
NOTE: This model is a default model for estimating releases to water from the Recirculating
Water-Cooling Tower Additive Releases source/activity. This model may not be used for any
other source/activity in ChemSTEER.
Potential Media of Release
Air, Incineration, Landfill and/or Water (default: 100% release to water)
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Cooling Tower Blowdown Loss Model default values for each of the input
parameters are summarized in Table A-15.
227
-------
ChemSTEER User Guide - Updated May 2015
Table A-15. Input Parameters and Default Values for the EPA/OPPT Cooling Tower Blowdown Loss
Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an
amount of the chemical that is
estimated to be released
Value of LFb from Mass Balance subtab Daily
Mass of Chemical Used (DMUchem) screen;
ChemSTEER default for LFb is 0.006
dimensionless
Amt
The amount of chemical to which
a loss fraction is applied
Value of DRR chem from Mass Balance subtab
Daily Mass of Chemical Used (DMUchem)
screen
kg/site-day
Freq
The frequency of release of the
chemical
OD
(from Mass Balance Parameters subtab of
Operation Parameters tab)
days/site-year
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
DR
Total daily release rate of tower
blowdown
Calculated from model equation
kg/site-day
AR
Total annual release rate of
tower blowdown
Calculated from model equation
kg/year (all
sites)
You may not change any parameter from Table A-15.
Default Parameter Value Switch Settings and Results Characterization:
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterizations for either Output 1 or Output 2 results are What-if.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Cooling Tower Blowdown Loss Model; up to 0.6% of the tower recirculation
rate"
Key Rationale for Model
To control the unwanted accumulation of nonvolatile components in a water-cooling tower,
periodic blowdown of the recirculating water must be performed. This model assumes as a default that
0.6% of the tower's recirculation rate is released to on- and/or off-site wastewater treatment as a result
of blowdown.
Reference
Summary Sheet: Recirculating Water-Cooling Tower, No date.
228
-------
ChemSTEER User Guide - Updated May 2015
Model Description
This model estimates the environmental release of solids during transfer activities (i.e.,
unloading and loading), and includes options for apportioning the release to various receiving media
based on the type of control technology employed.
Sources/Activities That Use This Model as a Default
The following sources/activities use the EPA/OPPT Solids Transfer Dust Loss Model as the
default for calculating releases of a chemical to air, water, incineration, or landfill:
• Unloading Solids from Transport Containers/Vessels (Raw Material or Product)
• Loading Solids into Transport Containers/Vessels (Raw Material or Product)
This model applies to loading/unloading of solid raw materials or products. It does not apply to
solid equipment cleaning, filter media changeout, or any other activities that may generate a dust (e.g.,
milling).
Potential Media of Release
The potential media of release and fraction of the total release to each are dependent upon the
optional dust emission control technology that is selected. These options are summarized in Table A-
16c.
NOTE: If you change the value(s) of DstCntrl and/or SrE and click OK in the View/ Update
Release model Information screen, the values of the percent to each medium of release will be
automatically updated according to the equations in Table A-16c. If you had previously changed
the media of release designations to non-default percentages, the changes will be overwritten,
and you will need to return to the Modify Media of Release window to re-enter your changes.
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Solids Transfer Dust Loss Model default values for each of the input parameters
are summarized in Table A-16.
229
-------
ChemSTEER User Guide - Updated May 2015
Table A-16. Input Parameters and Default Values for the EPA/OPPT Solids Transfer Dust Loss Model
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an
amount of the chemical that is
estimated to be released
0.005 (conservative)
dimensionless
Amt
The amount of chemical to which a
loss fraction is applied
Defaults specified in Table A-16a
kg/site-day
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
Freq
The frequency of release of the
chemical
Defaults specified in Table A-16b
days/site-year
DstCntrl
Dust control technology
Default: 0 (None)
Non-default options (see Table A-16c):
• Fabric filter/baghouse
• Mechanical/cyclone collectors
NA
SrE*
Solid removal efficiency of dust
control technology
Defaults specified in Table A-16c
dimensionless
DR
Daily release rate
Calculated from model equation
kg/site-day
AR
Annual release rate
Calculated from model equation
kg/year (all
sites)
*SrE is not used in the release calculations. It is used to specify the default media of release designations as shown
in Table A-16c.
You may elect to change any parameter from Table A-16 except the model estimates DR and
AR. Clicking the Type column for each changeable parameter other than LF, Amt and Freq contains only
two options: ChemSTEER defaults from Table A-16 and User-defined. The conditional default and non-
default options for Amt, Freq, and SrE are presented in the tables below. Be sure to read the
ChemSTEER Estimation Methods and Models topic for more information about changing model
parameters.
You may not change the defining model parameter, LF, to be anything other than the default
shown above. If you wish to model dust releases from solids transfer activities using your own loss
fraction, choose the User-Defined Loss Rate Model.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Conservative
Default Characterization of Output 2 Results: Conservative
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
230
-------
ChemSTEER User Guide - Updated May 2015
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Solids Transfer Dust Loss Model"
If DstCntrl is None, then add, "No dust controls are assumed as a worst case"
Otherwise add, "Dust emissions controlled by" [DstCntrl]
*lt is recommended that you update this default text as appropriate, especially to
specify a user-defined control technology.
Table A-16a. Conditional Default Values for Amt for the EPA/OPPT Solids Transfer Dust Loss Model
Source/Activity
Type/Operation
Mode
Batch
Condition
Operation
Type
Conditional Amt Default
(kg/site-day)
Non-default Options for
Amt*
Container-Related
/ Continuous
Not
Applicable
Any
MCi x Yi x Ned
(kg chemical/site-day)
(from Container Parameters
subtab of the Operation
Parameters tab)
MCi (kg material/container)
MCi x Yi (for Ned > 1 only)
DMIchem
DMOchem
User-defined Amt
Container-Related
/ Batch
Any
Any
MCi x Yi x Ned
(kg chemical/site-day)
(from Container Parameters
subtab of the Operation
Parameters tab)
MCi (kg material/container)
MCi x Yi (for Ned > 1 only)
BMIchem
BMOchem
BMIchem x Ls (kg/site-bt)
BMOchem x Ls (kg/site-bt)
BMIchem x Nbd
BMOchem x Nbd
BMIchem x Nbd/Ls (kg/line-
day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
231
-------
ChemSTEER User Guide - Updated May 2015
Table A-16b. Conditional Default Values for Freq for the EPA/OPPT Solids Transfer Dust Loss Model
Source/Activity
Type/Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default Options
for Freq*
Container-
Related/Continuous
Not Applicable
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
User-defined Freq
Container-
Related/Batch
Any
ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD
Nby
User-defined Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
Table A-16c. Conditional Default Values for Solids Removal Efficiency and Media of Release for the
EPA/OPPT Solids Transfer Dust Loss Model
Dust Control Technology
Setting
(DstCntrl)
Solids Removal Efficiency (SrE)
(dimensionless)
Default Media of Release Designations2
(in the Update Release Media Output
Specification screen of the Releases tab)
None (default)
0
% to Water or Air or Incineration or Landfill = 100
Mechanical
collector/cyclone
Non-default option4: 0.8 (low
end; conservative)
Non-default option3'4: 0.99 (high
end)
% to Incineration or Landfill = SrE x 100
% to Water or Air or Landfill = (1-SrE) x 100
Fabric filter/baghouse
Non-default option4: 0.99
(conservative)
% to Incineration or Landfill = SrE x 100
% to Water or Air or Landfill = (1-SrE) x 100
1. The model also indicates that scrubber control technology efficiency varies. Consult Figure 7-1 of the CEB
Engineering Manual (EPA 1991).
2. You may modify the default media of release designations and/or percentages directly in the Update Release
Media Output Specification screen of the Releases tab.
3. Non-default options for SrE are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
4. EPA 1991
Key Rationale for Model
The 0.5-percent loss rate (EPA, 2006) is the median of the upper bounds of dust loss data found
in available sources. Default solids removal efficiencies for each of the control technology options are
based on standard CEB low end/conservative estimates (EPA 1991).
References
US EPA Chemical Engineering Branch model entitled, Generic Model to Estimate Dust Releases
from Transfer/Unloading Operations of Solid Powders; July 20, 2007.
232
-------
ChemSTEER User Guide - Updated May 2015
Chapter 7 of the Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments; Washington, DC; Office of Toxic Substances, U.S. Environmental Protection
Agency; 1991; pp. 7-3 through 7-9.
Models for Calc
Model Description
This model estimates releases of overspray of non-volatile chemical in coatings during their
application to OEM automobiles using spray guns within a spray booth with controls to capture
overspray.
Sources/Activities That Use This Model as a Default
The EPA/OPPT Automobile OEM Coating Overspray Loss Model is the default for calculating
multi-media releases of a chemical to air, as well as water, incineration, or landfill for the Automobile
OEM Spray Coating Application source/activity.
This model is not used as an alternative release model for any other sources/activities.
Potential Media of Release
Air, Incineration, Landfill and/or Water (see Default Media of Release section below)
Default Media of Release
% to Air = (1-McE) x 100
% to Water = McE x (1- SrE) x 100
% to Landfill = McE x SrE x 100
NOTE: If you change the value(s) of McE and/or SrE and click OK in the View/ Update Release
Model Information screen, the values of the percent to each medium of release will be
automatically updated according to the above equations. If you had previously changed the
media of release designations to non-default percentages, the changes will be overwritten, and
you will need to return to the Modify Media of Release window to re-enter your changes.
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
233
-------
ChemSTEER User Guide - Updated May 2015
The EPA/OPPT Automobile OEM Coating Overspray Loss Model (non-volatiles) default values for
each of the input parameters are summarized in Table A-17.
Table A-17. Input Parameters and Default Values for the EPA/OPPT Automobile OEM Coating
Overspray Loss Model (non-volatiles)
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an amount of
the chemical that is estimated to be
released
1-TE
dimensionless
TE
Spray gun transfer efficiency
Value based on Table A-17a
dimensionless
McE
Spray mist capture efficiency
Output 1:
Default: 0.96 (waterwash/drv filter
default)
Non-default options: User-defined McE
dimensionless
Output 2:
Default: 0.96 (waterwash/drv filter
default)
Non-default option:User-defined McE
SrE
Solid removal efficiency from captured
mist
Output 1:
Default: 1 (drv filter default)
Non-default option: 0.90 (waterwash);
and User-defined SrE
dimensionless
Output 2:
Default: 0.90 (waterwash default)
Non-default option: 1 (drv filter); and
User-defined SrE
Amt
The amount of chemical to which a loss
fraction is applied
Value based on Table A-17b
kg/site-day
Freq
The frequency of release of the chemical
Value based on Table A-17c
days/site-
year
NS
Number of sites
NS
(from Mass Balance Parameters subtab
of the Operation Parameters tab)
site(s)
DR
Total daily overspray generation rate to
all media
Calculated from model equation
kg/site-day
AR
Total annual overspray generation rate to
all media
Calculated from model equation
kg/year
(all sites)
You may elect to change any parameter from Table A-17 except the model estimates LF, DR and
AR. Clicking the Type column for NS contains only two options: the ChemSTEER default from Table A-17
and User-defined. The conditional default and non-default options for TE, Amt and Freq are presented in
the tables below. Be sure to read the ChemSTEER Estimation Methods and Models topic for more
information about changing model parameters.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
234
-------
ChemSTEER User Guide - Updated May 2015
Default characterization for Output 1: Output 1
Default characterization for Output 2: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Automobile OEM Coating Overspray Loss Model (non-volatiles)"
Table A-17a. Default and Non-default Values for Coating Transfer Efficiency (TE) for the EPA/OPPT
Automobile OEM Coating Overspray Loss Model (non-volatiles)
Spray Gun Type (from the Shared Parameters/Factors subtab of
the Operation Parameters tab)
Conditional
Default TE
(Origin Label)
Non-default Options
for TE1
(Origin Label)
HVLP (High Volume, Low Pressure)
0.65 (HVLP Gun)
0.20 (Conv Gun)
User-Defined TE
(User Specified)
Conventional2
0.20 (Conv Gun)
0.65 (HVLP Gun)
User-defined TE
(User Specified)
1. The non-default options for TE may be selected at the model level. If the value for TE is changed in the Releases
tab, the new value will only be used in the calculations performed by the model for the selected release source.
2. Conventional spray guns are selected as the default for the Automobile OEM Spray Coating operation in the
Shared Parameters/ Factors subtab. The conventional spray gun default for the Automobile OEM Spray Coating
Operation was adopted as an internal policy decision in July 2003.
235
-------
ChemSTEER User Guide - Updated May 2015
Table A-17b. Conditional Default Values for Amt for the EPA/OPPT Automobile OEM Coating
Overspray Loss Model (non-volatiles)
Operation
Mode/Batch
Condition
Operation Type
Mass Balance
Basis
Conditional Amt Default
(kg/site-day)
Non-default Options for
Amt*
Continuous**/
Not Applicable
Auto Spray
Coating
Operations (OEM
or Refinish)
Formulated
Paint Usage**
DMUchem/DMOchem
(kg/site-day)
(from Mass Balance
Parameters subtab for
the Operation
Parameters tab)
DMIchem
User-defined Amt
Raw Material
(i.e., Purchased
Paint Usage
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMUchem
User-defined Amt
Not Auto Spray
Coating
Operation
Product
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMIchem
User-defined Amt
Raw Material
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMOchem
User-defined Amt
Batch / Number
of batches per
day
(Nbd)< 1
(from Mass
Any
Formulated
Paint Usage /
Product
BMOchem (kg/line-bt)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMIchem
BMIchem x Ls (kg/site-bt)
BMOchem x Ls (kg/site-bt)
User-defined Amt
Balance
Parameters
subtab of the
Operation
Parameters tab)
Purchased
Paint Usage /
Raw Material
BMIchem (kg/line-bt)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMOchem
BMIchem x Ls (kg/site-bt)
BMOchem x Ls (kg/site-bt)
User-defined Amt
Batch / Number
of batches per
day
(Nbd)> 1
(from Mass
Balance
Parameters
subtab of the
Any
Formulated
Paint Usage /
Product
BMOchem x Nbd
(kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMIchem
BMOchem
BMIchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Operation
Parameters tab)
Purchased
Paint Usage /
Raw Material
BMIchem x Nbd
(kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMIchem
BMochem
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
236
-------
ChemSTEER User Guide - Updated May 2015
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
**Continuous use of formulated paint is the default setting for the Automobile OEM Spray Coating operation on
the Mass Balance Parameters subtab.
Table A-17c. Conditional Default Values for Freq for the EPA/OPPT Automobile OEM Coating
Overspray Loss Model (non-volatiles)
Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default
Options for
Freq*
Continuous**
Not Applicable
OD
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
User-defined
Freq
Batch
Number of batches per day
(Nbd)< 1
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Nby
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
OD
User-defined
Freq
Number of batches per day
(Nbd)> 1
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
OD
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Nby
User-defined
Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
**Continuous is the default setting for the Automobile OEM Spray Coating operation on the Mass Balance
Parameters subtab.
Key Rationale for Model
The coating operation generates an overspray release based upon the amount of paint sprayed
and the transfer efficiency (TE). This overspray is controlled/contained within a spray booth with a
certain control removal efficiency (McE). As defaults, conventional spray guns and booths with
waterwash controls are assumed to be used for OEM automobile coating applications. When water type
booths are used, the solids removal efficiency (SrE) is not complete. Releases to the various media are
estimated based on these three primary parameters.
NOTE: This version of ChemSTEER calculates the daily overspray generation amounts only and
assumes that releases occur when the generation occurs. Future ChemSTEER versions will allow the
calculation of water purges and solids releases to other media at different release frequencies.
Reference
SAIC for US EPA/OPPT. Generic Scenario for Automobile Spray Coating Draft Report. August
1996.
237
-------
ChemSTEER User Guide - Updated May 2015
Organization for Economic Co-operation and Development. Emission Scenario Document on
Coating Application via Spray Painting in the Automotive Refinishing Industry. June 2010.
17 r 3/1 //innT a *. h. *!,¦¦* n n,. r ft *~ /.«/
Model Description
This model estimates releases of overspray of non-volatile chemical in coatings during their
application to refinished automobiles using spray guns within a spray booth with controls to capture
overspray from the exhaust.
Sources/Activities That Use This Model as a Default
The EPA/OPPT Automobile Refinish Coating Overspray Loss Model is the default for calculating
multi-media releases of a chemical to air, as well as water, incineration, or landfill for the Automobile
Refinish Spray Coating Application source/activity.
EPA/OPPT Automobile Refinish Coating Overspray Loss Model - Other Sources/Activities
The EPA/OPPT Automobile Refinish Coating Overspray Loss Model may be an appropriate
alternative to the default release model for the following sources/activities:
• Coating Using Hand Held Spray Gun
• Coating Using Hand Held Spray Can
Potential Media of Release
Air, Incineration, Landfill and/or Water (see Default Media of Release section below)
Default Media of Release
% to Air = (1-McE) x 100
% to Water = McE x (1- SrE) x 100
% to Landfill or Incineration = McE x SrE x 100
NOTE: If you change the value(s) of McE and/or SrE and click OK in the View/ Update Release
Model Information screen, the values of the percent to each medium of release will be
automatically updated according to the above equations. If you had previously changed the
media of release designations to non-default percentages, the changes will be overwritten, and
you will need to return to the Modify Media of Release window to re-enter your changes.
Equations
For daily releases:
DR (kg/site-day) = LF x Amt
DR occurs over [Freq] days/year
238
-------
ChemSTEER User Guide - Updated May 2015
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Automobile Refinish Coating Overspray Loss Model (non-volatiles) default values
for each of the input parameters are summarized in Table A-18.
239
-------
ChemSTEER User Guide - Updated May 2015
Table A-18. Input Parameters and Default Values for the EPA/OPPT Automobile Refinish Coating
Overspray Loss Model (non-volatiles)
Parameter
Description
Default Value(s)
Units
LF
Loss fraction; fraction of an amount of
the chemical that is estimated to be
released
1-TE
dimensionless
TE
Spray gun transfer efficiency
Output 1:
Default: 0.2 (conventional gun default)
Non-default option: User-defined TE
(see Table A-18a)
dimensionless
Output 2:
Default: 0.2 (conventional gun default)
Non-default option: User-defined TE
(see Table A-18a)
McE
Spray mist capture efficiency
Output 1:
Default: 0.96 (drv filter/waterwash
default)
Non-default options: User-defined McE
dimensionless
Output 2:
Default: 0.96 (drv filter/waterwash
default)
Non-default option: User-defined McE
SrE
Solid removal efficiency from captured
mist
Output 1:
Default: 1 (drv filter default)
Non-default option: 0.90 (waterwash);
and User-defined SrE
dimensionless
Output 2:
Default: 1 (drv filter default)
Non-default option: 0.90 (waterwash);
and User-defined SrE
Amt
The amount of chemical to which a loss
fraction is applied
Value based on Table A-18b
kg/site-day
Freq
The frequency of release of the chemical
Value based on Table A-18c
days/site-
year
NS
Number of sites
NS
(from Mass Balance Parameters subtab
of the Operation Parameters tab)
site(s)
DR
Total daily overspray generation rate to
all media
Calculated from model equation
kg/site-day
AR
Total annual overspray generation rate
to all media
Calculated from model equation
kg/year
(all sites)
You may elect to change any parameter from Table A-18 except the model estimates LF, DR and
AR. Clicking the Type column for NS contains only two options: the ChemSTEER default from Table A-18
and User-defined. The conditional default and non-default options for TE, Amt and Freq are presented in
the tables below. Be sure to read the ChemSTEER Estimation Methods and Models topic for more
information about changing model parameters.
240
-------
ChemSTEER User Guide - Updated May 2015
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
Default characterization for Output 1: Typical
Default characterization for Output 2: Worst-Case
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Automobile Refinish Coating Overspray Loss Model (non-volatiles)"
Table A-18a. Default and Non-default Values for Coating Transfer Efficiency (TE) for the EPA/OPPT
Automobile Refinish Coating Overspray Loss Model (non-volatiles)
Spray Gun Type
(from the Shared Parameters/Factors subtab of the Operation
Parameters tab)
Conditional Default
TE
(Origin Label)
Non-default Options
for TE1
(Origin Label)
HVLP (High Volume, Low Pressure)
0.65 (HVLP Gun)
0.20 (Conv Gun)
User-Defined TE
(User Specified)
Conventional2
0.20 (Conv Gun)
0.65 (HVLP Gun)
User-defined TE
(User Specified)
1. The non-default options for TE may be selected at the model level. If the value for TE is changed in the Releases
tab, the new value will only be used in the calculations performed by the model for the selected release source.
2. Conventional spray guns are selected as the default for the Automobile Refinish Spray Coating operation in the
Shared Parameters/ Factors subtab.
241
-------
ChemSTEER User Guide - Updated May 2015
Table A-18b. Conditional Default Values for Amt for the EPA/OPPT Automobile Refinish Coating
Overspray Loss Model (non-volatiles)
Operation
Mode/Batch
Condition
Operation Type
Mass Balance
Basis
Conditional Amt Default
(kg/site-day)
Non-default Options for
Amt*
Continuous**/
Not Applicable
Auto Spray
Coating
Operations (OEM
or Refinish)
Formulated
Paint Usage**
DMUchem/DMOchem
(kg/site-day)
(from Mass Balance
Parameters subtab for
the Operation
Parameters tab)
DMIchem
User-defined Amt
Purchased
Paint Usage**
(i.e., Raw
Material)
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMUchem
User-defined Amt
Not Auto Spray
Coating
Operation
Product
DMOchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMIchem
User-defined Amt
Raw Material
DMIchem (kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
DMOchem
User-defined Amt
Batch / Number
of batches per
day
(Nbd)< 1
(from Mass
Any
Formulated
Paint Usage /
Product
BMOchem (kg/line-bt)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMIchem
BMIchem x Ls (kg/site-bt)
BMOchem x Ls (kg/site-bt)
User-defined Amt
Balance
Parameters
subtab of the
Operation
Parameters tab)
Purchased
Paint Usage /
Raw Material
BMIchem (kg/line-bt)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMOchem
BMIchem x Ls (kg/site-bt)
BMOchem x Ls (kg/site-bt)
User-defined Amt
Batch / Number
of batches per
day
(Nbd)> 1
(from Mass
Balance
Parameters
subtab of the
Any
Formulated
Paint Usage /
Product
BMOchem x Nbd
(kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMIchem
BMOchem
BMIchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
(kg/line-day)
User-defined Amt
Operation
Parameters tab)
Purchased
Paint Usage /
Raw Material
BMIchem x Nbd
(kg/site-day)
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
BMIchem
BMochem
BMOchem x Nbd
BMIchem x Nbd/Ls
(kg/line-day)
BMOchem x Nbd/Ls
242
-------
ChemSTEER User Guide - Updated May 2015
(kg/line-day)
User-defined Amt
*Non-default options for Amt are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
**Continuous use of purchased paint is the default setting for the Automobile Refinish Spray Coating operation on
the Mass Balance Parameters subtab.
Table A-18c. Conditional Default Values for Freq for the EPA/OPPT Automobile Refinish Coating
Overspray Loss Model (non-volatiles)
Operation
Mode
Batch Condition
Conditional Freq Default
(days of release/site-yr)
Non-Default
Options for
Freq*
Continuous**
Not Applicable
OD
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
User-defined
Freq
Batch
Number of batches per day
(Nbd)< 1
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Nby
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
OD
User-defined
Freq
Number of batches per day
(Nbd)> 1
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
OD
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Nby
User-defined
Freq
*Non-default options for Freq are available by clicking in the Type column in the View/Update Release Model
Information screen in the Releases tab.
**Continuous is the default setting for the Automobile Refinish Spray Coating operation on the Mass Balance
Parameters subtab.
Key Rationale for Model
The coating operation generates an overspray release based upon the amount of paint sprayed
and a transfer efficiency (TE). This overspray is controlled/contained within a spray booth with a certain
control removal efficiency (McE). As defaults, conventional spray guns and booths with dry filters are
assumed to be used for automobile refinish coating applications. When water type booths are used, the
solids removal efficiency (SrE) is not complete. Releases to the various media are estimated based on
these three primary parameters.
NOTE: This version of ChemSTEER calculates the daily overspray generation amounts only and
assumes that releases occur when the generation occurs. Future ChemSTEER versions will allow
the calculation of water purges and solids releases to other media at different release
frequencies.
Reference
Organization for Economic Co-operation and Development. Emission Scenario Document on
Coating Application via Spray Painting in the Automotive Refinishing Industry. June 2010.
243
-------
ChemSTEER User Guide - Updated May 2015
Model Description
This model estimates the releases of additives due to rinses of parts removed from the
electroplating baths. The rinse water is treated to recover usable additives that are returned to the
baths. The additives that are not recovered are expected to be discharged to on-site treatment, where
additives are expected to partition to wastewater and sludge, which is assumed to be sent to land or
incineration disposal.
NOTE: This model is the default model for estimating releases to water and land/incineration
from the Rinsing Electroplated Parts source/ activity. This model may not be used for any other
source/activity in ChemSTEER.
Potential Media of Release
Air, Incineration, Land and/or Water (see Default Media of Release section below)
Default Media of Release
% to Water = (1- WWTE) x 100
% to Land or Incineration = WWTE x 100
NOTE: If you change the value of WWTE and click OK in the View/ Update Release Model
Information screen, the values of the percent to each medium of release will be automatically
updated according to the above equations. If you had previously changed the media of release
designations to non-default percentages, the changes will be overwritten, and you will need to
return to the Modify Media of Release window to re-enter your changes.
Equations
For daily releases:
DR (kg/site-day) = DVrinse x 3.78 L/gal x Yrinse x Drinse x (1 - RinseE)
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Electroplating Rinse Water Loss Model default values for each of the input
parameters are summarized in Table A-19.
244
-------
ChemSTEER User Guide - Updated May 2015
Table A-19. Input Parameters and Default Values for the EPA/OPPT Electroplating Rinse Water Loss
Model
Parameter
Description
Default Value(s)
Units
DVrinse
Daily volume of rinsewater
generated per site
DVrinse
(from Mass Balance Parameters subtab of
Operation Parameters tab)
(default: 4,932)
gal/site-day
Drinse
Density of the rinse water
Drinse
(from Mass Balance Parameters subtab of
Operation Parameters tab)
(default: 1)
kg/L
Yrinse
Concentration of PMN in rinse
water
Yrinse
(from Mass Balance Parameters subtab of
Operation Parameters tab)
(default: 0.0235)
dimensionless
RinseE
Rinse water recovery efficiency
RinseE
(from Mass Balance Parameters subtab of
Operation Parameters tab)
(default: 0.9)
dimensionless
WWTE
Wastewater treatment efficiency
Value based on Table A-19a
dimensionless
Freq
The frequency of release of the
chemical
OD
(from Mass Balance Parameters subtab of
Operation Parameters tab)
day/site-year
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
DR
Total daily release
Calculated from model equation
kg/site-day
AR
Total annual release
Calculated from model equation
kg/year (all
sites)
You may not change the value of the any parameter from Table A-19 except WWTE. Clicking the
Type column for WWTE launches a window that displays the conditional default and non-default
options, which are shown in Table A-19a. Be sure to read the ChemSTEER Estimation Methods and
Models topic for more information about changing model parameters.
Default Parameter Value Switch Settings and Results Characterization:
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterization for Output 1: Output 1
Default characterization for Output 2: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis:
245
-------
ChemSTEER User Guide - Updated May 2015
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Electroplating Rinse Water Loss Model"
Table A-19a. Default and Non-default Values for Wastewater Treatment Efficiency (WWTE) for the
EPA/OPPT Electroplating Rinse Water Loss Model
Electroplating Additive Type
(from the Shared Parameters/Factors subtab of
the Operation Parameters tab)
Conditional Default WWTE
(Origin Label)
Non-Default Options for
WWTE1
(Origin Label)
Suspended Solids
0.97 (Suspended Solids)
0.5 (Organic Compounds)
User-defined TE
(User Specified)
Organic Compounds2
0.5 (Organic Compounds)
0.97 (Suspended Solids)
User-Defined TE
(User-Specified)
1. The non-default options for WWTE may be selected at the model level. If the value for WWTE is changed in the
Releases tab, the new value will only be used in the calculations performed by the model for the selected release
source. To maintain consistency for all models, you should only change WWTE in the Shared Parameters/ Factors
subtab.
2. Organic compounds are selected as a worst case default in the Shared Parameters/Factors subtab.
Key Rationale for Model
Rinse water is treated and 90% of the additives are recovered and returned to the electroplating
baths. The additives that are not recovered are assumed to be discharged to on-site treatment, where
additives are expected to partition to wastewater and sludge, which is assumed to be sent to land or
incineration disposal.
Reference
SAICfor US EPA/OPPT. Generic Scenario: Electroplating. August 1996.
EPA/OPPT Electroplating Spent Bath Disposal Model
Model Description
This model estimates the releases of additives due to periodic disposal of spent electroplating
baths. The baths are discharged to on-site treatment, where additives in the baths are expected to
partition to wastewater and sludge, which is assumed to be sent to land or incineration disposal.
NOTE: This model is the default model for estimating releases to water and land/incineration
from the Changing Electroplating Bath source/ activity. This model may not be used for any other
source/activity in ChemSTEER.
Potential Media of Release
Air, Incineration, Land and/or Water (see Default Media of Release section below)
246
-------
ChemSTEER User Guide - Updated May 2015
Default Media of Release
% to Water = (1- WWTE) x 100
% to Land or Incineration = WWTE x 100
NOTE: If you change the value of WWTE and click OK in the View/ Update Release Model
Information screen, the values of the percent to each medium of release will be automatically updated
according to the above equations. If you had previously changed the media of release designations to
non-default percentages, the changes will be overwritten, and you will need to return to the Modify
Media of Release window to re-enter your changes.
Equations
For daily releases:
DR (kg/site-day) = (DVbath x 3.78L/gal x Ybath x Dbath)
DR occurs over [Freq] days/year
For annual releases:
AR (kg/year) = DR x Freq x NS, AR is for all sites combined
Model Input Parameters and Default Values
The EPA/OPPT Electroplating Spent Bath Disposal Model default values for each of the input
parameters are summarized in Table A-20.
247
-------
ChemSTEER User Guide - Updated May 2015
Table A-20. Input Parameters and Default Values for the EPA/OPPT Electroplating Spent Bath Disposal
Model
Parameter
Description
Default Value(s)
Units
DVbath
Daily volume of bath change
Vbath x Nbath
(from Mass Balance Parameters subtab of
Operation Parameters tab)
(default: 2,500x3 = 7,500)
Non-default option*: Vbath
gallons
Dbath
Density of the bath
Dbath
(from Mass Balance Parameters subtab of
Operation Parameters tab)
(default: 1)
kg/L
Ybath
Concentration of chemical in
bath
Ybath
(from Mass Balance Parameters subtab of
Operation Parameters tab)
(default: 0.0434)
dimensionless
WWTE
Wastewater treatment
efficiency
Value based on Table A-20a
dimensionless
Freq
The frequency of release of
the chemical
Freqbath
(from Mass Balance Parameters subtab of
Operation Parameters tab)
(default: 2)
Non-default option*: Freqbath x Nbath
day/site-year
NS
Number of sites
NS
(from Mass Balance Parameters subtab of
Operation Parameters tab)
site(s)
DR
Total daily release
Calculated from model equation
kg/site-day
AR
Total annual release
Calculated from model equation
kg/year (all
sites)
* ChemSTEER automatically "pairs" the default and non-default options for DVbath and Freq. If you select the
default for one parameter, the default of the other parameter is used. If you select the non-default of one
parameter, the non-default of the other parameter is used.
You may change the values of the following parameters from Table A-20: DVbath and Freq
("paired" default and non-default options only as specified in Table A-20) and WWTE. Clicking the Type
column for any of these changeable parameters launches a window that displays the options. The
conditional default and non-default options for WWTE are presented in Table A-20a. Be sure to read the
ChemSTEER Estimation Methods and Models topic for more information about changing model
parameters.
Default Parameter Value Switch Settings and Results Characterization:
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterization for Output 1: Output 1
Default characterization for Output 2: Output 2
248
-------
ChemSTEER User Guide - Updated May 2015
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis:
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Electroplating Spent Bath Disposal Model"
Table A-20a. Default and Non-default Values for Wastewater Treatment Efficiency (WWTE) for the
EPA/OPPT Electroplating Spent Bath Disposal Model
Electroplating Additive Type
(from the Shared Parameters/Factors subtab of
the Operation Parameters tab)
Conditional Default WWTE
(Origin Label)
Non-Default Options for
WWTE1(Origin Label)
Suspended Solids
0.97 (Suspended Solids)
0.5 (Organic Compounds)
User-defined TE
(User Specified)
Organic Compounds2
0.5 (Organic Compounds)
0.97 (Suspended Solids)
User-Defined TE
(User-Specified)
1. The non-default options for WWTE may be selected at the model level. If the value for WWTE is changed in the
Releases tab, the new value will only be used in the calculations performed by the model for the selected release
source. To maintain consistency for all models, you should only change WWTE in the Shared Parameters/Factors
subtab.
2. Organic compounds are selected as a worst case default in the Shared Parameters/ Factors subtab.
Key Rationale for Model
This model assumes that releases of additives occur due to semi-annual, simultaneous (as
default) disposal of spent electroplating baths. The model assumes that the entire volume of each bath
tank is disposed. The spent baths are assumed to be discharged to on-site treatment, where additives in
the baths are expected to partition to wastewater and sludge, which is assumed to be sent to land or
incineration disposal.
Reference
SAICfor US EPA/OPPT. Generic Scenario: Electroplating. August 1996.
Models for Calculating Releases of Liquids
Releases Due to Evaporation
The following models may be selected for sources/activities that result in releases due to
evaporation:
• EPA/OPPT Mass Transfer Coefficient Model
• EPA/OPPT Penetration Model
• EPA/OPPT Cooling Tower Evaporative Loss Model (volatiles)
• User-Defined Vapor Generation Rate Model
249
-------
ChemSTEER User Guide - Updated May 2015
• User-Defined Loss Rate Model
Releases During Container Filling (Vapor Displacement)
The following models may be selected for sources/activities that result in releases during
container filling:
• EPA/OAQPS AP-42 Loading Model
• User-Defined Vapor Generation Rate Model
• User-Defined Loss Rate Model
The following models may be selected for sources/activities that result in releases of residual
and waste liquids:
• EPA/OPPT Bulk Transport Residual Model
• EPA/OPPT Drum Residual Model
• EPA/OPPT Multiple Process Vessel Residual Model
• EPA/OPPT Single Vessel Residual Model
• EPA/OPPT Small Container Residual Model
• EPA/OPPT Water Saturation Loss Model
• EPA/OPPT Automobile OEM Coating Overspray Loss Model
• EPA/OPPT Automobile Refinish Coating Overspray Loss Model
• EPA/OPPT Cooling Tower Blowdown Loss Model
• EPA/OPPT Cooling Tower Windage Loss Model
• EPA/OPPT Electroplating Rinse Water Loss Model
• EPA/OPPT Electroplating Spent Bath Disposal Model
• User-Defined Loss Rate Model
Models for Cak
Releases of Residual Solids
The following models may be selected for sources/activities that result in releases of residual
solids:
• EPA/OPPT Solid Residuals in Transport Containers Model
• EPA/OPPT Solids Transfer Dust Loss Model
• User-Defined Loss Rate Model
250
-------
ChemSTEER User Guide - Updated May 2015
Worker Exposures
General Guidelines fo sure Assessment
Detailed descriptions of the worker exposure models are contained in several User Guide topics,
organized according to the type of exposure (e.g., inhalation or dermal), the form of the substance (e.g.,
liquid or solid material), and models that utilize exposure limits as the basis for the calculation. Simply
click on the desired grouping of models in the User Guide Table of Contents to access these detailed
descriptions.
Each manufacturing, processing, and use operation to be assessed are analyzed to determine
the sources/ activities that can result in worker exposures that are to be estimated. Once these sources/
activities are identified, a general hierarchy of preference may be used to determine how to quantify
each exposure from each source/ activity. The following list shows the potential methods for quantifying
exposures in order (generally) from the most preferred to the least preferred.
1. Measured personal exposure monitoring data for the chemical.
2. "Indirectly" measured area exposure concentration monitoring data.
3. Measured data for a "surrogate" chemical with similar "exposure-affecting" properties
and used in the same (or very similar) process.
4. Modeled exposure estimates:
• Simulated exposure estimates (e.g., mass balance model) for the chemical.
• Regulated limits as an estimated "upper bound" of exposure.
• "Rule-of-thumb" exposure estimates, or those developed using analogous points of
reference and engineering judgment.
This order of preference is expected to apply generally to most cases of worker exposure
assessment. However, judgment may dictate that, in some cases, the order within the hierarchy should
be changed. Examples of such a change of hierarchy order may include when data are judged to be
unreliable or unrepresentative for a particular reason. Also, some estimates may be a combination of
two or more of these methods.
Estimation methods in ChemSTEER are based on a combination of factors:
• research and knowledge of and data from unit operations and industrial processes,
• some basic chemical engineering principles,
• professional experience and judgment.
Standard methods and models in ChemSTEER have been developed to estimate worker
exposures for a variety of industrial and commercial operations.
Quick Summary of Chem! alation Exposure Models
251
-------
ChemSTEER User Guide - Updated May 2015
All of the ChemSTEER inhalation exposure models are summarized in the table below. For each
model, a brief description of the primary calculation(s), as well as a list of the ChemSTEER worker
activities (or activity categories) that use the model as the default for calculating exposures, are
provided.
NOTE: This table is intended to provide you a "snapshot" of the various ChemSTEER models to
help you become more familiar with them. You are highly encouraged to review the full
description of the models (provided in this section of the User Guide), as well as the
source/activity topics (provided in the Release Sources and Exposure Activities section of the
User Guide), for a more complete description of the calculations and logic used.
252
-------
ChemSTEER User Guide - Updated May 2015
Quick Summary of ChemSTEER Inhalation Exposure Models
Inhalation Exposure Model
Brief Description of Calculation or Basis of the
Inhalation Potential Dose Rate (mg/day)
[l=Cm x bx h]
Activities That Use the Model as a Default for Calculating
Exposures
Models for Calculating Worker Inhalation Exposure to a Chemical Vapor
NOTE: These models only appear as defaults for calculating exposures to a volatile chemical (i.e., the adjusted vapor pressure (AVP) of the material being
handled is within the specified AVP range).
EPA/OPPT Mass Balance Inhalation
Model
Cm = mass concentration of the chemical in air
(mg/m3)
= Cvx MW/Vm
Where:
Cv = volumetric concentration of the chemical
in air (ppm) (uses model equation that utilizes
G* (vaporization rate (g/s)) and other shared
parameters)
MW = molecular weight of the chemical
(g/mol)
Vm = molar volume (L/mol) (default: 24.45 @
25 °C and 1 atm)
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h* = exposure duration (hrs/day)
*You must select and run a corresponding vapor
generation release model for the activity in order
to obtain appropriate default values for the G and
h parameters. Be sure to read this model's User
Guide topic for more information.
Loading Liauids into Transport Containers/Vessels (all activity
types)
Unloading Liauids from Transport Containers/Vessels (all
activity types)
Cleaning Liauid Residuals from Transport Containers/Vessels
(all activity types)
Sampling Liauids (all activity tvpes)
Vapor Release from Open Liquid Surfaces
OSH PEL-Limiting Model for Substance
Specific Vapors
Cm = mass concentration of the chemical in air
(mg/m3)
=Cvx MW/Vm
There are no activities that use this model as a default for
calculating worker inhalation of the chemical vapor.
253
-------
ChemSTEER User Guide - Updated May 2015
Where:
Cv* = volumetric concentration in air (ppm)
(uses model equation that utilizes user-input
values for several parameters, including a
concentration limit (e.g., PEL))
MW = molecular weight of the chemical
(g/mol)
Vm = molar volume (L/mol) (default: 24.45 @
25 °C and 1 atm)
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
*Be sure to read this model's User Guide topic for
more information.
NOTE: You may choose this model for any volatile liquid-
handling activity for which you wish to base the exposure
estimates on a known permissible limit.
Near-Field / Far-Field Inhalation
Exposure Model
Cm = mass concentration of the chemical in air
(mg/m3) (uses model equation that utilizes G*
(vaporization rate (g/s)) and other shared
parameters)
b = volumetric inhalation rate (m3/hr) (default:
1.25)
There are no activities that use this model as a default for
calculating worker inhalation of the chemical vapor.
NOTE: You may choose this model for any volatile liquid-
handling activity.
h* = exposure duration (hrs/day)
*You must select and run a corresponding vapor
generation release model for the activity in order
to obtain appropriate default values for the G and
h parameters. Be sure to read this model's User
Guide topic for more information.
254
-------
ChemSTEER User Guide - Updated May 2015
Models for Calculating Worker Inhalation Exposures to a Chemical Mist
OSHA Total PNOR PEL-Limiting Model | Cm = mass concentration of the chemical in air
(mg/m3)
= KCkx Ys
Where:
KCk = mass concentration limit of total
particulate in air (mg/m3) (default: 15)
Coating Using Hand-Held Spray Gun
NOTE: This model is also the default model for several solids
processing activities. Please refer to the Chemical Dust
Exposure section of this table for a list of those activities.
Ys = weight fraction of the chemical in the
airborne particulate
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
OSHA Respirable PNOR PEL-Limiting
Model
Cm = mass concentration of the chemical in air
(mg/m3)
= KCk x Ys
Where:
KCk = mass concentration limit of total
particulate in air (mg/m3) (default: 5)
There are no activities that use this model as a default for
calculating worker inhalation of the chemical mist.
NOTE: You may choose this model for any fine mist-generating
activity for which you wish to base the exposure estimates on
the generic permissible limit for respirable particles.
Ys = weight fraction of the chemical in the
airborne particulate
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
OSHA PEL-Limiting Model for
Substance-Specific Particulates
Cm = mass concentration of the chemical in air
(mg/m3)
= KCk x Ys/Ypel
Operating the Electroplating Bath Uses OSHA PEL for chromium
(KCk=0.5 mg/m3) and est. chromium batch concentration
(Ypel=0.25) as overriding defaults.
Where:
KCk = mass concentration limit of total
NOTE: You may choose this model for any mist-generating
activity for which you wish to base the exposure estimates on a
255
-------
ChemSTEER User Guide - Updated May 2015
particulate in air (mg/m3) (default: 15, but you
may enter a PEL for a known chemical
substance in the mist)
Ys = weight fraction of the chemical in the
airborne particulate
Ypel = weight fraction of the substance in the
mist for which the PEL is known
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
known permissible limit.
EPA/OPPT UV Roll-Coating Inhalation
Model
Cm = mass concentration of the chemical in air
(mg/m3)
= KCkx Ys
Roll Coating
Where:
KCk = mass concentration of total particulate
in air (mg/m3) (default: between 0.04 and
0.26)
Ys = Lesser of Ymist/Ysf or 1; Ymist = weight
fraction of the chemical in the mist; Ysf =
weight fraction of solids/non-volatile
components in the mist
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
Models for Calculating Worker Inhalation Exposures to a Chemical Dust
Inhalation Dose Rate (I) = EFx AH xYsxSd
EPA/OPPT Small Volume Handling
Model
Where:
EF = exposure factor (mg/kg) (default: between
Sampling Solids (all activity types)
This model also may be the default for the following activities,
if the amount of solids being handled is < 54 kg/worker-dav:
256
-------
ChemSTEER User Guide - Updated May 2015
0.0477 and 0.161)
Loading Solids into Transport Containers/Vessels (all activity
AH = amount of solids containing the chemical
types)
being handled in the activity (kg/worker-shift)
Unloading Solids from Transport Containers/Vessels (all activity
Ys = weight fraction of the chemical in the dust
types)
Sd = number of shifts per worker, per day
Cleaning Solid Residuals from Transport Containers/Vessels (all
activity types)
Eauipment Cleaning Losses of Solids
Miscellaneous Activities Related to Solid Processing
OSHA Total PNOR PEL-Limiting Model
Cm = mass concentration of the chemical in air
Grinding and Sanding
(mg/m3)
= KCk x Ys
This model may also be the default for the following activities,
if the amount of solids being handled is > 54 kg/worker-dav.
Where:
KCk = mass concentration limit of total
Loading Solids into Transport Containers/vessels (all activity
particulate in air (mg/m3) (default: 15)
types)
Ys = weight fraction of the chemical in the
Unloading Solids from Transport Containers/Vessels (all activity
airborne particulate
types)
b = volumetric inhalation rate (m3/hr) (default:
Eauipment Cleaning Losses of Solids
1.25)
Miscellaneous Activities Related to Solid Processing
h = exposure duration (hrs/day) (default: 8)
NOTE: This model is also the default model for mist-producing
activities. Please refer to the Chemical Mist Exposure section of
:: 1
this table for a list of those activities.
OSHA Respirable PNOR PEL-Limiting
Cm = mass concentration of the chemical in air
There are no activities that use this model as a default for
Model
(mg/m3)
calculating worker inhalation of the chemical dust.
= KCk x Ys
NOTE: You may choose this model for any fine dust-generating
Where:
activity for which you wish to base the exposure estimates on
KCk = mass concentration limit of total
the generic permissible limit for respirable particles.
257
-------
ChemSTEER User Guide - Updated May 2015
particulate in air (mg/m3) (default: 5)
Ys = weight fraction of the chemical in the
airborne particulate
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
Cm = mass concentration of the chemical in air
There are no activities that use this model as a default for
Substance-Specific Particulates
(mg/m3)
calculating worker inhalation of the chemical dust.
= KCk x Ys/Ypel
NOTE: You mav choose this model for anv dust-generating
Where:
activity for which you wish to base the exposure estimates on a
KCk = mass concentration limit of total
known permissible limit.
particulate in air (mg/m3) (default: 15, but you
may enter a PEL for a known chemical
substance in the dust)
Ys = weight fraction of the chemical in the
airborne particulate
Ypel = weight fraction of the substance in the
mist for which the PEL is known
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
Cm = mass concentration of the chemical in air
Roll Coating
Model
(mg/m3)
= KCk x Ys
Where:
KCk = mass concentration of total particulate
in air (mg/m3) (default: between 0.04 and
J J 0.26)
258
-------
ChemSTEER User Guide - Updated May 2015
Ys = lesser of Ymist/Ysf or 1; Ymist = weight
fraction of the chemical in the mist; Ysf =
weight fraction of solids/non-volatile
components in the mist
b = volumetric inhalation rate (m3/hr) (default:
1-25)
h = exposure duration (hrs/day) (default: 8) j
Models for Calculating Exposures During Industry-Specific Activities
EPA/OPPT Automobile OEM Spray
Coating Inhalation Exposure Model
(non-volatile non-polyisocyanates)
Cm = mass concentration of the chemical in air
(mg/m3)
= KCkx Ys
Automobile OEM Spray Coating Application
(used in the Automobile OEM Spray
Coating operation)
Where:
KCk = mass concentration of total particulate
in air (mg/m3) (default: 2.3, based on spray
gun type and spray booth ventilation type)
Ys = lesser of Ymist/Ysf or 1; Ymist = weight
fraction of the chemical in the mist; Ysf =
weight fraction of solids/non-volatile
components in the mist
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
EPA/OPPT Automobile Refinish Spray
Cm = mass concentration of the chemical in air 1 Automobile Refinish Sprav Coating Application
Coating Inhalation Exposure Model
(mg/m3)
(non-volatile non-polyisocyanates)
= KCkxYs
(used in the Automobile Refinish Spray
Where:
Coating operation)
KCk = mass concentration of total particulate
in air (mg/m3) (default: 15, based on spray gun
type and spray booth ventilation type)
259
-------
ChemSTEER User Guide - Updated May 2015
Ys = lesser of Ymist/Ysf or 1; Ymist = weight
fraction of the chemical in the mist; Ysf =
weight fraction of solids/non-volatile
components in the mist
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
EPA/OPPT Automobile Spray Coating
Inhalation Exposure Model (non-
volatile polyisocyanates)
(can be used in either of the
Automobile Spray Coating operations)
Cm = mass concentration of the chemical in air
(mg/m3)
= KCk
Where:
KCk = mass concentration of polyisocyanate
mists/dusts in air (mg/m3) (default is based on
spray gun type and spray booth ventilation
type; ranges between 0.01 and 18.4)
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h = exposure duration (hrs/day) (default: 8)
There are no activities that use this model as a default for
calculating worker inhalation of the chemical overspray
mists/dusts.
NOTE: It is recommended that you substitute this model for the
default inhalation model in either of the Automobile Spray
Coating operations if the chemical being assessed is a
polyisocyanate compound.
Models for Calculatina Durina Other Generic Unit Operations
User-Defined Inhalation Model
Cm = mass concentration of the chemical in air
(mg/m3)
Aqueous Wash of Organic Mass
(can be used to estimate exposures to
a chemical vapor or particulate/mist)
=Cvx MW/Vm xYs
Where:
Cv* = volumetric concentration in air (ppm)
(uses model equation that utilizes user-input
values for several parameters, including a
volumetric concentration)
MW = molecular weight of the chemical
(g/mol)
Scrubber Releases
Coating Using Hand-Held Spray Can
Miscellaneous Activities Related to Liquid Processing
NOTE: You may choose this model for any activity for which
you wish to base the exposure estimates on a known
volumetric airborne concentration of the chemical.
260
-------
ChemSTEER User Guide - Updated May 2015
Vm = molar volume (L/mol) (default: 24.45 @
25 °C and 1 atm)
Ys = weight fraction of the chemical in the
mixture (default: 1)
b = volumetric inhalation rate (m3/hr) (default:
1.25)
h* = exposure duration (hrs/day)
*lf assessing an exposure to a chemical vapor, it is I I
recommended that you select and run a
corresponding vapor generation release model I I
for the activity in order to obtain appropriate
default values for several of the parameters. Be
sure to read this model's User Guide topic for
more information.
261
-------
ChemSTEER User Guide - Updated May 2015
Quick Summar ernSTEER Dermal Exposure Models
All of the ChemSTEER dermal exposure models are summarized in the table below. For each
model, a brief description of the primary calculation(s), as well as a list of the ChemSTEER worker
activities (or activity categories) that use the model as the default for calculating exposures, is provided.
NOTE: This table is intended to provide you a "snapshot" of the various ChemSTEER models to
help you become more familiar with them. You are highly encouraged to review the full
description of the models (provided in this section of the User Guide), as well as the
source/activity topics (provided in the Release Sources and Exposure Activities section of the
User Guide), for a more complete description of the calculations and logic used.
262
-------
ChemSTEER User Guide - Updated May 2015
Quick Summary of ChemSTEER Dermal Exposure Models
Dermal Exposure Model
Brief Description of Calculation or Basis
of Dermal Potential Dose Rate
(mg/day)
[Dexp = S x Qu x Yderm x FT]
Activities That Use the Model as a Default for Calculating Exposures
Models for Calculating Worker Dermal Exposures to a Liquid Chemical
EPA/OPPT 1-Hand Dermal
Contact with Liquid Model
S = surface area of contact (cm2)
(default: 535 for one hand)
Qu = quantity remaining on skin
(mg/cm2-event) (default: ranges
between 0.7 and 2.1)
Yderm = weight fraction of chemical in
the liquid
FT = frequency of events
(events/worker-day) (default: 1)
Sampling Liauids (all activity tvoes)
EPA/OPPT 2-Hand Dermal
Contact with Liquid Model
S = surface area of contact (cm2)
(default: 1,070 for two hands)
Qu = quantity remaining on skin
(mg/cm2-event) (default: ranges
between 0.7 and 2.1)
Yderm = weight fraction of chemical in
the liquid
FT = frequency of events
(events/worker-day) (default: 1)
Loading Liauids into Transport Containers/Vessels (all activity tvpes)
Unloading Liauids from Transport Containers/Vessels (all activity tvpes)
Cleaning Liauid Residuals from Transport Containers/Vessels (all activity types)
Aqueous Wash of Organic Mass
Liquid/Liquid Extraction Solvent Disposal
EPA/OPPT 2-Hand Dermal
Immersion in Liquids Model
S = surface area of contact (cm2)
(default: 1,070 for two hands)
Qu = quantity remaining on skin
(mg/cm2-event) (default: ranges
between 1.3 and 10.3)
Miscellaneous Activities Related to Liquid Processing
Automobile OEM Spray Coating Application (used in the Automobile OEM Spray
Coating Operation)
Automobile Refinish Spray Coating Application (used in the Automobile Refinish
Spray Coating operation)
263
-------
ChemSTEER User Guide - Updated May 2015
Yderm = weight fraction of chemical in
the liquid
FT = frequency of events
(events/worker-day) (default: 1)
Models for Calculating Worker Dermal Exposures to a Solid Chemical
EPA/OPPT Direct 2-Hand Dermal
Contact with Solids Model
S x Qu = total amount of solids
remaining on hands (mg/event)
(default: 3,100)
Yderm = weight fraction of chemical in
the liquid
FT = frequency of events
(events/worker-day) (default: 1)
Loading Solids into Transport Containers/Vessels (all activity types)
Unloading Solids from Transport Containers/Vessels (all activity types)
Cleaning Solid Residuals from Transport Containers/Vessels (all activity types)
Sampling Solids (all activity type)
Equipment Cleaning Losses of Solids
Filter Media Changeout
Grinding and Sanding
Miscellaneous Activities Related to Solids Processing
EPA/OPPT 2-Hand Contact with
Container Surfaces Model
S x Qu = total amount of solids
remaining on hands (mg/event)
(default: 1,100)
Yderm = weight fraction of chemical in
the liquid
FT = frequency of events
(events/worker-day) (default: 1)
There are no activities that use this model as a default for calculating worker
dermal exposures to the chemical adhered to container surfaces.
NOTE: It is recommended that you substitute this model for the default dermal
model for any activity that would involve this type of worker contact.
Models for Calculating Exposures During Industry-Specific Activities
Currently, there are no industry-specific activity dermal exposure models.
Models for Calculating Exposures During Other Generic Unit Operations
User-Defined Dermal Model I S = surface area of contact (cm2) (you
There are no activities that use this model as the default for calculating worker
264
-------
ChemSTEER User Guide - Updated May 2015
(can be used to estimate dermal
exposures to either a liquid or
solid chemical)
must choose or enter a value)
Qu = quantity remaining on skin
(mg/cm2-event) (you must choose or
enter a value)
dermal exposures to the chemical.
NOTE: You may substitute this model for the default dermal model for any
activity for which you wish to enter an alternative known dermal surface area
(S) and/or quantity remaining on the skin (Qu).
Yderm = weight fraction of chemical in
liquid
FT = frequency of events
(events/worker-day) (default: 1)
265
-------
ChemSTEER User Guide - Updated May 2015
List of C and NIOSH RELs
ChemSTEER includes various Occupational Safety and Health Administration (OSHA) Permissible
Exposure Limits (PELs) and National Institute for Occupational Safety and Health (NIOSH) Recommended
Exposure Limits (RELs) for more than 650 chemicals and other substances.
These PELs and RELs were obtained from the U.S. EPA's Endocrine Disruptor Priority Setting
Database (EDPSD). These values were originally obtained from the following sources:
• NIOSH Pocket Guide (available on line at http://www.cdc.gov/niosh/npg/npg.html)
• Existing OSHA standards establishing PELs (available on line at:
http://www.osha.gov/SLTC/pel/index.html)
• Additional exposure limits (i.e., STELs and CLs) documented in the 1988 OSHA Project
Documentation website: http://www.cdc.gov/niosh/pel88/pelstart.html
To view ChemSTEER's set of PELs and RELs, click the View Exposure Limits button on the
Chemical tab. The View OSHA PELs and NIOSH RELs window will appear. The selected Chemical Name,
CAS Number, and Molecular Weight are displayed at the top of the window. There are also two subtabs:
PEL Information and REL Information. In each of the subtabs, the PEL or REL information is displayed for
the selected chemical. ChemSTEER's set of PELs and RELs incorporate at least one of the following
values:
Time-weighted average (TWA) PEL or REL concentration (Note: all TWAs are 8-hr
averages, unless otherwise noted);
PEL or REL short-term exposure limits (STELs); and
PEL or REL ceiling (CL) exposure limits.
Each of the exposure limits are in units of mg/m3 and parts-per-million (ppm). In many cases, the
data source reported the limit in only one of these two units of measure. ERG used the chemical's
molecular weight to convert the exposure limits into either mg/m3 or ppm, as appropriate, using the
following equations:
To convert an exposure limit concentration reported in mg/m3 into ppm:
mg/m3 x 24.45 L/mol
ppm=
MW
To convert an exposure limit concentration reported in ppm into mg/m3:
ppm x MW
mg/m =
24.45 L/mol
Each of the PEL or REL values (i.e., TWAs, STELs, and CLs) includes an indicator of whether that
value (ppm or mg/m3) was obtained by way of one of the above conversions. For example,
Formaldehyde (CAS 50-00-0) has an OSHA 8-hr TWA PEL of 0.75 ppm. The PEL Information subtab
266
-------
ChemSTEER User Guide - Updated May 2015
displays: "PEL TWA Converted (ppm? No". This indicates that the displayed TWA PEL of 0.75 ppm was
taken directly from the source and was not the result of a conversion. Formaldehyde also includes a
TWA PEL of 0.9212 mg/m3, with "PEL TWA Converted (mg/m3)? Yes". This indicates that the TWA PEL
of 0.9212 mg/m3 was converted from the published ppm value using the equation above.
Some substances' PEL and/or REL limits could not be converted, as there is no molecular weight
value for the substance (e.g., in the case of "wood dust" or "kaolin" exposure limits).
In addition, the set of exposure limits contains an OSHA TWA PEL concentration in units of
millions of particles per cubic foot of air (mp/cfa) for the following substances:
• Mica (silicates):
• Talc (containing no asbestos fibers);
• Silica, amorphous, diatomaceous earth (uncalcined);
• Silica, amorphous, precipitated and gel; and
• Graphite.
The list also contains a NIOSH TWA REL for "fibrous glass" in units of fibers per cubic centimeter
(f/cc).
Maneuvering the Set of PELs and RELs
Located at the bottom of each of the View OSHA PELs and NIOSH RELs window, the following
buttons allow you to scroll through the set of PELs or RELs:
• Click either the Next > or < Previous buttons to move from one chemical record to
another.
• Click the «< First button to move directly to the first chemical record.
• Click the Last »> button to move directly to the last chemical record.
You may search for a particular chemical record or filter the displayed set of chemical exposure
limits by clicking the New Search button. Records can be filtered by either chemical name or CAS
number. To return the full set of records, simply click the New Search button, leave the search field
blank, and click Search to return to the exposure limit subtabs.
Models for Calculating In
Model Description
This model utilizes worst case and typical exposure rates to estimate the amount of chemical
inhaled by a worker during handling of "small volumes" (<54 kg/worker-shift) of solid/powdered
materials containing the chemical. The handling of these small volumes is presumed to be scooping,
weighing, and pouring of the solid materials.
267
-------
ChemSTEER User Guide - Updated May 2015
Sources/Activities That Use This Model as a Default
The EPA/OPPT Small Volume Solids Handling Inhalation Model is the default for calculating
worker inhalation exposures to a chemical while performing any source/activity for Sampling Solids.
Other Sources/Activities
The EPA/OPPT Small Volume Solids Handling Model may be an appropriate alternative to the
default inhalation model for the following sources/activities:
Where the amount of material being handled is less than 54 kg/day:
• All sources/activities for Cleaning Solid Residuals from Transport Containers/Vessels
• All sources/activities for Loading Solids into Transport Containers/Vessels
• All sources/activities for Unloading Solids from Transport Containers/Vessels
• Equipment Cleaning Losses of Solids
• Miscellaneous Sources/Activities Related to Solid Processing
NOTE: If the amount of material being handled is unknown or was not calculated, the OSHA
Total PNOR PEL-Limiting Model will be used as a default.
This model may be also used for the Filter Media Changeout source/activity, regardless of the
amount of material.
Potential Route / Form(s) of Exposure
Inhalation / Particulate
Equations
Parameters
Description
Equation
Units
1
Inhalation potential dose rate
EFxAH xYsxSd
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
Model Input Parameters and Default Values
The EPA/OPPT Small Volume Handling Inhalation Model default values for each of the input
parameters are summarized in Table B-l.
268
-------
ChemSTEER User Guide - Updated May 2015
Table B-l. Input Parameters and Default Values for the EPA/OPPT Small Volume Handling Inhalation
Model
Parameter
Description
Default Value(s)
Units
EF
Exposure Factor (mg exposure per kg
solid handled)
Output 1:
Default: 0.0477 (Tvoical)
Non-default: 0.161 (Worst Case)
mg/kg
Output 2:
Default: 0.161 (Worst Case)
Non-default Option: 0.0477 (Tvoical)
AH
The amount of solids/powder (containing
the chemical) handled (0 < AH < 54)
Defaults specified in Table B-la
kg/worker-
shift
Ys
Weight fraction of chemical in particulate
(0 < Ys < 1)
Defaults specified in Table B-lb
dimensionless
Sd
Number of shifts worked by each worker
during a workday (0 < Sd < 3)
1
shift/worker-
day
NWexp
Number of workers exposed while
performing the activity
1
worker/site
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
site(s)
ED
Days exposed per year (0 < ED (integer) <
365)
Defaults specified in Table B-lc
days/site-yr
EY
Years of occupational exposure (0 < EY)
40
years
BW
Body weight (0 < BW)
70
kg
ATc
Averaging time over a lifetime (chronic) (0
< ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-l except EF, which is a constant. Clicking
the Type column for each changeable parameter other than EF, AH, Ys, and ED contains only two
options: ChemSTEER defaults from Table B-l and User-defined. The conditional default and non-default
options for AH, Ys, and ED are presented in the tables below. Be sure to read the ChemSTEER Estimation
Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameter, EF, to be anything other than one of the
defaults shown above. If you wish to model inhalation exposures to solids using your own data, choose
one of the following alternative models:
OSHA PEL-Limiting Model for Substance-Specific Particulates: or
User-Defined Inhalation Model.
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
269
-------
ChemSTEER User Guide - Updated May 2015
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
Settings for either Output 1 or Output 2 results are based on which EF is selected for the
corresponding output:
• Results using the typical exposure factor are characterized as Typical by default.
• Results using the worst case exposure factor are characterized as Worst Case by default.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA Small Volume Handling Model, less than 54 kg of PMN handled per site-day"
270
-------
ChemSTEER User Guide - Updated May 2015
Table B-la. Conditional Default Values for AH for the EPA/OPPT Small Volume Handling Inhalation
Model
Source/ Activity
Type/ Operation
Mode
Batch Condition
Operation
Type
Conditional AH Default*
(kg/worker-shift)
Non-default Options
for AH**
Container-
Related /
Continuous
Not Applicable
Any
MCi x Ned (kg/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
DMIrm
DMOprod
User-defined AH
Container-
Related / Batch
Any
Any
MCi x Ned (kg/site-day)
(from Container
Parameters subtab of
the Operation
Parameters tab)
BMIrm
BMOprod
BMIrm x Ls (kg/site-
bt)
BMOprod x Ls
(kg/site-bt)
BMIrm x Nbd
BMOprod x Nbd
BMIrm x Nbd/Ls
(kg/line-day)
BMOprod x Nbd/Ls
(kg/line-day)
User-defined AH
Not Container-
Related /
Continuous
Not Applicable
Manufacturing
DMOprod (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMIrm
User-defined AH
Processing
Use
DMIrm (kg/site-day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
DMOprod
User-defined AH
Not Container-
Related / Batch
Number of batches per
day(Nbd)< 1
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
Manufacturing
BMOprod (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIrm
BMIrm x Ls (kg/site-
bt)
BMOprod x Ls
(kg/site-bt)
User-defined AH
Processing
Use
BMIrm (kg/line-bt)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMIprod
BMIrm x Ls (kg/site-
bt)
BMOprod x Ls
(kg/site-bt)
User-defined AH
Number of batches per
day(Nbd)> 1
(from Mass Balance
Parameters subtab of
Manufacturing
BMOprod x Nbd (kg/site-
day)
(from Mass Balance
Parameters subtab of
BMIrm
BMOprod
BMIrm x Nbd
BMIrm x Nbd/Ls
271
-------
ChemSTEER User Guide - Updated May 2015
the Operation
the Operation
(kg/line-day)
Parameters tab)
Parameters tab)
BMOprod x Nbd/Ls
(kg/line-day)
User-defined AH
Processing
BMIrm x Nbd (kg/site-
BMIrm
Use
day)
(from Mass Balance
Parameters subtab of
the Operation
Parameters tab)
BMOprod
BMOprod x Nbd
BMIrm x Nbd/Ls
(kg/line-day)
BMOprod x Nbd/Ls
(kg/line-day)
User-defined AH
* If the parameter or equation results in a default for AH > 54 kg/site-day, then ChemSTEER will display a pop-up
warning and will not allow you to run the model until you select an option for which AH < 54 kg/site-day.
**Non-default options for AH are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for AH are available for both Output 1
and Output 2.
EPA Assessment Policy Recommendation: It is recommended that, for solid residue cleaning
activities, the amount of solid residue cleaned from or disposed with the emptied container,
vessel, or process (i.e., the loss fraction x total amount in the container, vessel, or process) be
used for AH in verifying the use of this model and in the calculations.
Table B-lb. Conditional Default Values for Ys for the EPA/OPPT Small Volume Handling Inhalation
Model
Source / Activity Type / Material
Named in Source/Activity Label
Operation
Type
Conditional Ys Default
Non-default
Options for Ys*
Container-Related / Any
Any
Yi
(from the Container Parameters
subtabs of the Operation Parameters
tab)
Yrm
Yprod
User-defined Ys
Not Container-Related / Raw
Material
Any
Yrm
(from the Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
Not Container-Related / Product
Any
Yprod
(from Mass Balance Parameters subtab
of the Operation Parameters tab)
Yrm
User-defined Ys
Not Container-Related / Neither
Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters subtab
of the Operation Parameters tab)
Yrm
User-defined Ys
Processing
Use
Yrm
(from the Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
*Non-default options for Ys are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for Ys are available for both Output 1
and Output 2.
272
-------
ChemSTEER User Guide - Updated May 2015
Table B-lc. Conditional Default Values for ED for the EPA/OPPT Small Volume Handling Inhalation
Model
Source/ Activity
Type/ Operation
Mode
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED*
Container-Related /
Continuous or Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-
yr)
User-defined ED
Not Container-
Related / Continuous
Not Applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-
Related / Batch
Number of batches per day
(Nbd)< 1
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per day
(Nbd)> 1
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for ED are available for both Output 1
and Output 2.
Key Rationale for Model
Worst case and typical exposure factor data (i.e., 0.161 mg/kg and 0.0477 mg/kg, respectively)
were derived from a study of dye weighing and adapted for use in situations where workers are
presumed to handle small volumes of solids in a manner similarto the handling in the study. The
maximum amount of dye handled in the study was 54 kg per site-day. The exposure concentration is the
same as the concentration of the chemical in the mixture.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (p. 4-11)
US EPA Chemical Engineering Branch Generic Scenario, Textile Dyeing, 10/15/92.
Textile Dye Weighing Monitoring Study. Exposure Evaluation Division, Economics and
Technology Division, Office of Toxic Substances, U.S. Environmental Protection Agency,
Washington, D.C. April 1990. EPA 560/5-90-009.
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
273
-------
ChemSTEER User Guide - Updated May 2015
Model Description
This model estimates the amount of chemical inhaled by a worker (typical and worst case)
during an activity in which chemical vapor is generated. Estimation of the concentration for inhalation
exposure is based on a vapor generation rate (G) estimated from a release model or from a user-input
vapor generation rate. The following release models are vapor generation models:
EPA/OAQPS AP-42 Loading Model
EPA/OPPT Mass Transfer Coefficient Model
EPA/OPPT Penetration Model
User-Defined Vapor Generation Rate Model
Sources/Activities That Use This Model as a Default
The EPA/OPPT Mass Balance Inhalation Model is the default for calculating worker inhalation
exposures to a volatile chemical while performing the following sources/activities:
• All sources/activities involving Cleaning Liquid Residuals from Transport
Containers/Vessels
• All sources/activities involving Loading Liquids into Transport Containers/Vessels
• All sources/activities involving Unloading Liquids from Transport Containers/Vessels
• All sources/activities involving Sampling Liquids
• Vapor Releases from Open Liquid Surfaces
NOTE: This model will be preselected for those activities in which the model is a default for
calculating inhalation exposures; however, if the adjusted vapor pressure of the substance being
handled (e.g., AVPrm, AVPprod) (calculated on the Operation Parameters tab, Shared
Parameters/Factors subtab) is outside of the preferred range of adjusted vapor pressures (i.e., is
less than AVPlow or greater than AVPhigh), then the model will not be selected. To read more
about these settings, refer to the following topics:
• Vapor Model Activation
• Operation Parameters Tab -> Shared Parameters/Factors Subtab
Other Sources/Activities
The EPA/OPPT Mass Balance Inhalation Model may be an appropriate alternative to the default
inhalation model for the following sources/activities:
• All sources/activities for Equipment Cleaning Losses of Liquids
• Miscellaneous Sources/Activities Related to Liquid Processing
• Aqueous Wash of Organic Mass
274
-------
ChemSTEER User Guide - Updated May 2015
• Distillation Column Bottoms Disposal
• Filter Media Changeout
• Liquid/Liquid Extraction Solvent Disposal
• Scrubber Releases
Roll Coating
Potential Route / Form(s) of Exposure
Inhalation / Vapor
Equations
Parameters
Description
Equation
Units
Cv
Volumetric concentration of
chemical in air
Lesser of [(170,000 x Tx G) / (MW xQxk)] or
[1,000,000 xXx VP/760]
ppm
Cm
Mass concentration of chemical
in air
Cv x MW / Vm
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers
exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-
day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-
day
APDR
Acute potential dose rate
l/BW
mg/kg-
day
Model Input Parameters and Default Values
The EPA/OPPT Mass Balance Inhalation Model default values for each of the input parameters
are summarized in Table B-2.
275
-------
ChemSTEER User Guide - Updated May 2015
Table B-2. Input Parameters and Default Values for the EPA/OPPT Mass Balance Inhalation Model
Parameter
Description
Default Value(s)
Units
T
Temperature of air (0 < T)
298
K
G
Vapor generation rate
G
(from the associated vapor generation model* or a
User-defined G in the Release tab)
g/s
MW
Molecular weight of the
chemical (0 < MW)
MW
(from chemical tab)
g/mol
Q
Ventilation rate (0 < Q)
Defaults specified in Table B-2a
ft3/min
k
Mixing factor (0 < k < 1)
Defaults specified in Table B-2a
dimensionless
X
Vapor pressure correction
factor (mole fraction or
other) (0 < X < 1)
X
(from the associated vapor generation model* or
from the Shared Parameters/Factors subtab -
Defaults specified in Table B-2b)
dimensionless
VP
Vapor pressure of the pure
chemical being assessed (0 <
VP)
VP
(from the associated vapor generation model* or
VPchem from the Chemical tab)
torr
Vm
Molar volume (0 < Vm)
24.45 @ 25°C, 1 atm
L/mol
b
Volumetric inhalation rate (0
< b < 7.9)
1.25
m3/hr
h
Exposure duration (0 < h <
24)
Defaults specified in Table B-2c
hrs/day
ED
Days exposed per year (0 <
ED (integer) < 365)
Defaults specified in Table B-2d
days/site-yr
NWexp
Number of workers exposed
while performing the activity
1
workers/site
NS
Number of sites
NS
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
site(s)
EY
Years of occupational
exposure (0 < EY)
40
years
BW
Body weight (0 < BW)
70
kg
ATc
Averaging time over a
lifetime (chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT <
ATc)
EY
years
*See Table B-2e for the hierarchy of logic for extracting G, X, and VP values from an associated release model.
You may elect to change any parameter from Table B-2. Clicking the Type column for each
changeable parameter other than X and ED, contains only two options: ChemSTEER defaults from Table
B-2 and User-defined. The default values of Q and k are dependent upon the selected source/activity
and are summarized in Table B-2a. Similarly, the default value for h is dependent upon the selected
source/activity, as summarized in Table B-2c. The conditional default and non-default options for X and
ED are presented in Tables B-2b and B-2d, respectively. Be sure to read the ChemSTEER Estimation
Methods and Models topic for more information about changing model parameters.
276
-------
ChemSTEER User Guide - Updated May 2015
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Typical
Default Characterization of Output 2 Results: Worst Case
NOTE: If you change the default value for either Q or k, the Characterization of Results will be
automatically reset to Output 1 or Output 2 (as appropriate). You may select an alternative
characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT Mass Balance Model"
277
-------
ChemSTEER User Guide - Updated May 2015
Table B-2a. Conditional Default Values for k and Q for the EPA/OPPT Mass Balance Inhalation Model
Vapor Generation Model
Used for Source / Activity /
Default Q1 (cfm)
(Characterization of Parameter Value)
Default k1 (dimensionless)
(Characterization of Parameter Value)
Transport Container (if
applicable)
Outputl
Output2
Output 1
Output 2
Outdoor Defaults:
EPA/OAQPS AP-42 Loading
Model / Rail Cars, Tank
Trucks,
or
EPA/OPPT Mass Transfer
Coefficient Model
237,600
(average)
26,400 x (60 x vz /
5280)3 (worst case)
(vz in ft/min; from
associated vapor
generation model on
Releases tab)
0.5
(Typical)
0.1
(Worst Case)
Indoor Defaults:
EPA/OAQPS AP-42 Loading
Model / Transporting
containers other than Rail
Cars, Tan Trucks
or
EPA/OPPT Penetration
Model
or
User-defined G or No vapor
generation model used
3,000
(Typical)
500
(Worst Case)
0.5
(Typical)
0.1
(Worst Case)
Source: Chemical Engineering Branch Manual for the Preparation of Engineering Assessments (Tables 4-11 and 4-
12)
1. Higher values for both parameters, Q and k, result in lower exposure estimates (i.e., as Output 1 results) based
on the model equations.
2. The average default ventilation rate (Q) for outdoor activities is based upon an average wind speed of 9 mph
(792 ft/min).
3. If the vapor generation model (e.g., EPA/OAQPS AP-42 Loading Model, etc.) does not use the parameter vz,
ChemSTEER will use the default of 440 ft/min.
278
-------
ChemSTEER User Guide - Updated May 2015
Table B-2b. Conditional Default Values for X for the EPA/OPPT Mass Balance Inhalation Model
Associated Vapor
Generation Model*
Material named in
Source/Activity
Label
Operation
Type
Conditional X Default
Non-Default
Options for
X**
Yes
Any
Any
X
(from associated vapor
generation model* in the
Releases tab)
Xrm
Xprod
Xother
User-
defined X
No
or The associated vapor
generation model does
not contain an X value
Raw Material
Any
Xrm
(from Shared
Parameters/Factors subtab)
Xprod
Xother
User-
defined X
Product
Any
Xprod
(from Shared
Parameters/Factors subtab)
Xrm
Xother
User-
defined X
Other
Any
Xother
(from Shared
Parameters/Factors subtab)
Xrm
Xother
User-
defined X
Not material-specific
Manufacturing
Xprod
(from Shared
Parameters/Factors subtab)
Xrm
Xother
User-
defined X
Processing
Use
Xrm
(from Shared
Parameters/Factors subtab)
Xprod
Xother
User-
defined X
*See Table B-2e for the hierarchy of logic for extracting an X value from an associated release model.
**Non-default options for X are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for X are available for both Output 1
and Output 2.
279
-------
ChemSTEER User Guide - Updated May 2015
Table B-2c. Conditional Default Values for h for the EPA/OPPT Mass Balance Inhalation Model
Associated Release
Model
Source / Activity Type
Conditional h Default*
(hrs/site-day)
Yes
Any type
Lesser of 8 or OHa from an associated release
model**
(from Releases tab)
No
Container-Related
Lesser of 8 or OHa
(from Container Parameters subtab of the
Operation Parameters tab)
Sampling
1
Equipment Cleaning Losses of Liquids from
Multiple Vessels
4
Equipment Cleaning Losses of Liquids from
a Single, Large Vessel
1
Equipment Cleaning Losses of Liquids from
a Single, Small Vessel
0.5
Not Container-Related, Sampling, or
Equipment Cleaning
8
*You may select the conditional default h (shown above) or enter a user-defined h for either Output 1 or Output 2
for all sources/activities. The conditional default h values were adopted as a policy decision in 2002.
**See Table B-2e for the hierarchy of logic for extracting an h value from an associated release model.
Table B-2d. Conditional Default Values for ED for the EPA/OPPT Mass Balance Inhalation Model
Associated Release Model /
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED**
Yes
/ Container-related
/ Continuous
Not applicable
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
OD (days/site-yr)
ODa (days/site-yr)
User-defined ED
Yes
/ Container-related
/ Batch
Any
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
Nby (bt/site-yr)
OD (days/site-yr)
ODa (days/site-yr)
User-defined ED
Yes
/ Not Container-related
/ Continuous
Not applicable
Lesser of 250 or Freq from
associated release model*
(from Release tab)
OD (days/site-yr)
User-defined ED
Yes
/ Not Container-related
/ Batch
Any
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
Nby (bt/site-yr)
OD (days/site-yr)
User-defined ED
No associated release model
/ Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operations
Parameters tab)
OD (das/site-yr)
User-defined ED
No associated release model
/Container-Related
/Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operations
Parameters tab)
Nby (bt/site-yr)
OD (days/st-yr)
User-defined ED
280
-------
ChemSTEER User Guide - Updated May 2015
No associated release model Not applicable
/ Not Container-Related
/Continuous
Lesser of 250 or OD User-defined ED
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
No associated release model Number of batches per day
/ Not Container-Related (Nbd) < 1
/ Batch (from Mass Balance
Parameters subtab of the
Operation Parameters tab)
Lesser of 250 or Nby OD (days/site-yr)
(from Mass Balance User-defined ED
Parameters subtab of the
Operation Parameters tab)
Number of batches per day
(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
Lesser of 250 or OD 1 Nby (bt/site-yr)
(from Mass Balance User-defined ED
Parameters subtab of the
Operation Parameters tab)
*See Table B-2e for the hierarchy of logic for extracting an ED value from an associated release model.
**Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for ED are available for both Output 1
and Output 2.
Table B-2e. Hierarchy for Extracting Parameter Defaults from Associated Release Models* for the
EPA/OPPT Mass Balance Inhalation Model
1. Use current value of parameter from the last associated vapor generation model* for the
source/activity (from the Releases tab).
2. Use current value of parameter from the last associated release model* for the source/activity (from
the Releases tab) - only if there is no associated vapor generation model.
3. If no associated release model* for the source/activity, then use conditional default as described for
"No associated release model" in Tables B-2b, and B-2c, and B-2d above.
*The associated release model is the LAST vapor generation or release model that contains a parameter
value required for the EPA/OPPT Mass Balance Inhalation Model that is listed in the Release Model(s)for
Selected Activity box in the Releases tab (i.e., it is the last vapor generation or release model that was
added by either ChemSTEER or the user) for the selected Source/Activity.
When extracting parameter values from the Releases tab, the EPA/OPPT Mass Balance Model
Input Parameters for Output 1 are obtained from the associated release model Input Parameters for
Output 1; and the EPA/OPPT Mass Balance Model Input Parameters for Output 2 are obtained from the
associated release model Input Parameters for Output 2.
Key Rationale for Model
The airborne concentration of the chemical is estimated to be a function of the source vapor
generation rate and the volumetric ventilation rate within a given space and includes simplifying
assumptions of steady state (constant generation rate and constant ventilation rate) and a mixing factor
(for non-ideal mixing of air). The default ventilation rates and mixing factors provide a typical and worst
case estimate of exposure. The airborne concentration of the chemical cannot exceed the level of
saturation for the chemical.
References
281
-------
ChemSTEER User Guide - Updated May 2015
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-1, 4-5, 4-14)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
Fehrenbacher, M.C. and Hummel, A.A. "Evaluation of the Mass Balance Model Used by the
Environmental Protection Agency for Estimating Inhalation Exposure to New Chemical
Substances". American Industrial Hygiene Association Journal. June 1996. 57: 526-536.
OSHA PEL-Limiting Model for Substance-Specific Particulates
Model Description
This model estimates the amount of a chemical inhaled by a worker during handling of
solid/powdered materials containing the chemical when the material/ mixture contains a specific
substance with an OSHA Permissible Exposure Limit (PEL), Time-Weighted Average (TWA) or Ceiling (C).
The estimate assumes that the worker is exposed to the chemical at a level limited by the OSHA PEL
(TWA or C).
Sources/Activities That Use This Model as a Default
The OSHA PEL-Limiting Model for Substance-Specific Particulates is the default for calculating
worker inhalation exposures to a chemical contained in a mist while performing the Operating the
Electroplating Bath activity.
NOTE: When used in this activity, the model uses the OSHA PEL for chromium (KCk=0.5 mg/m3)
and an estimated chromium concentration in an electroplating bath (Ypel=0.25) as overriding
defaults to those discussed below.
Other Sources/Activities
The OSHA PEL-Limiting Model for Substance-Specific Particulates may also be an appropriate
means to calculate worker inhalation exposures to a solid, particulate chemical while performing the
following sources/activities:
• All sources/activities for Cleaning Solid Residuals from Transport Containers/Vessels
• All sources/activities for Loading Solids into Transport Containers/Vessels
• All sources/activities for Unloading Solids from Transport Containers/Vessels
• All sources/activities for Sampling Solids
Coating Applications:
• Roll Coating
• Coating Using Hand Held Spray Gun
282
-------
ChemSTEER User Guide - Updated May 2015
• Coating Using Hand Held Spray Can
• Automobile OEM Spray Coating Application
• Automobile Refinish Spray Coating Application
Other Sources/Activities:
• Equipment Cleaning Losses of Solids
• Miscellaneous Sources/Activities Related to Liquid Processing Miscellaneous
Sources/Activities Related to Solid Processing
Potential Route / Form(s) of Exposure
Inhalation / Particulate or Mist
Equations
Parameters
Description
Equation
Units
Cm
Mass concentration of chemical in air
KCk x Ys/Ypel
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
Model Input Parameters and Default Values
The OSHA PEL-Limiting Model for Substance-Specific Particulates (TWA or C) default values for
each of the input parameters are summarized in Table B-3.
283
-------
ChemSTEER User Guide - Updated May 2015
Table B-3. Input Parameters and Default Values for the OSHA PEL-Limiting Model for Substance-
Specific Particulates (TWA or C)
Parameter
Description
Default Value(s)
Units
KCk
Mass concentration of the chemical or metal
with a PEL in air (based on OSHA PEL-TWA)
15 (PNOR PEL)
mg/m3
Ys
Weight fraction of chemical in particulate (0
< Ys < 1)*
Defaults specified in Table B-3a
dimensionless
Ypel
Weight fraction of chemical or metal with a
PEL in particulate (0 < Ypel < 1)*
1
dimensionless
b
Volumetric inhalation rate (0 < b < 7.9)
1.25
m3/hr
h
Exposure duration (0 < h < 24)
8
hrs/day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number of sites
NS
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
site(s)
ED
Days exposed per year (0 < ED (integer) <
365)
Defaults specified in Table B-3d
days/site-yr
EY
Years of occupational exposure (0 < EY)
40
years
BW
Body weight (0 < BW)
70
kg
ATc
Averaging time over a lifetime (chronic) (0 <
ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
* Rather than using the specified weight fractions Ys and Ypel, you may also choose to enter relative mass values
where Ys would be a relative weight of the chemical assessed and Ypel would be a relative weight of the substance
with a PEL. For example, if in some total mixture there are 150 kg of chemical assessed for every 50 kg of
substance with a PEL, any ratio of Ys: Ypel of 3 is valid. An option would be for you to enter 0.15 for Ys and 0.05 for
Ypel. Another option would be for you to enter 0.3 for Ys and 0.1 for Ypel.
You may elect to change any parameter from Table B-3, except when h is a constant for a PEL
that is based upon a specific TWA or C. The value of h may be changed when the PEL is a ceiling. Clicking
the Type column for each changeable parameter other than Ys and ED contains only two options:
ChemSTEER defaults from Table B-3 and User-defined. The conditional default and non-default options
for Ys and ED are presented in the tables below. Be sure to read the ChemSTEER Estimation Methods
and Models topic for more information about changing model parameters.
In future versions of ChemSTEER, non-default options for KCk will consist of a pick list of OSHA
PELs for specific chemicals or metals from the Occupational Safety and Health Administration General
Industry Air Contaminants Standard (29 CFR 1910.1000). In this version, you must determine and enter
the appropriate value manually.
ChemSTEER contains a list of various OSHA PELS, as well as NIOSH Recommended Exposure
Limits (RELs), for more than 700 chemicals and other substances. You may view this list by clicking on
the View/Update Exposure Limits button, found on the Chemicals tab. To read more about this list, go to
the List of OSHA PELS and NIOSH RELs topic.
284
-------
ChemSTEER User Guide - Updated May 2015
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Upper Bound
Default Characterization of Output 2 Results: Upper Bound
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"OSHA PEL-Limiting Model for Substance-specific Particulates (TWA or C)"
285
-------
ChemSTEER User Guide - Updated May 2015
Table B-3a. Conditional Default Values for Ys for the OSHA PEL-Limiting Model for Substance-Specific
Particulates (TWA or C)
Source / Activity Type / Material
Names in Source/Activity Type
Operation
Type
Conditional Ys Default
Non-default
Options for Ys*
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtabs of the Operation Parameters
tab)
Yrm
Yprod
User-defined Ys
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
Not Container-Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined Ys
Not Container-Related
/Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined Ys
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
*Non-default options for Ys are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
286
-------
ChemSTEER User Guide - Updated May 2015
Table B-3b. Conditional Default Values for ED for the OSHA PEL-Limiting Model for Substance-Specific
Particulates (TWA or C)
Source/ Activity
Type/ Operation
Mode
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED*
Container-Related /
Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-
yr)
User-defined ED
Container-Related /
Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-
yr)
User-defined ED
Not Container-
Related / Continuous
Not Applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-
Related / Batch
Number of batches per day
(Nbd)< 1
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per day
(Nbd)> 1
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Key Rationale for Model
Operations are generally expected to comply with OSHA's federal regulation regarding
inhalation of specific chemicals. This model assumes that the exposure concentration of the chemical is
at a ratio such that the concentration of the substance with a PEL is not exceeded.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-1, 4-11)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
OSHA PEL-Limiting Model for Substance-Specific Vapors
Model Description
287
-------
ChemSTEER User Guide - Updated May 2015
This model estimates the amount of vapor for a specific chemical inhaled by a worker during
handling of liquid material containing the chemical when the mixture contains a chemical with an OSHA
Permissible Exposure Limit (PEL), Time-Weighted Average (TWA) or Ceiling (C), or when controls are in
place that would limit exposure of a chemical with an OSHA PEL. The estimate assumes that the worker
is exposed to the chemical with a PEL at a level no greater than the OSHA PEL (TWA or C).
Some of the default input parameter values used by this model are derived from an associated
release model used to estimate releases of vapors during the activity. The following release models may
provide the default values for some input parameters:
EPA/OAQPS AP-42 Loading Model
EPA/OPPT Mass Transfer Coefficient Model
EPA/OPPT Penetration Model
User-Defined Vapor Generation Rate Model
Sources/Activities That Use This Model as a Default
There are no sources/activities in ChemSTEER that use this model as a default for calculating
worker inhalation exposures to a chemical.
Other Sources/Activities
The OSHA PEL-Limiting Model for Substance-Specific Vapors may be an appropriate means to
calculate worker exposures to a volatile chemical while performing the following sources/activities:
• All sources/activities for Cleaning Liquid Residuals from Transport Containers/Vessels
• All sources/activities for Equipment Cleaning Losses of Liquids
• All sources/activities for Loading Liquids into Transport Containers/Vessels
• All sources/activities for Unloading Liquids from Transport Containers/Vessels
• All Generic Coating Applications sources/activities
• All Automobile Spray Coating sources/activities
• Miscellaneous Sources/Activities Related to Liquid Processing
• Vapor Releases from Open Liquid Surfaces
Unit Operations and Processes:
• Aqueous Wash of Organic Mass
• Distillation Column Bottoms Disposal
• Filter Media Changeout
• Liquid/Liquid Extraction Solvent Disposal
• Scrubber Releases
288
-------
ChemSTEER User Guide - Updated May 2015
Potential Exposure Route
Inhalation / Vapor
Equations
Parameters
Description
Equation
Units
Cvk
Volumetric concentration of
chemical in air
Lesser of [(Cvk x (VP x Ys / MW) / (VPpel x Ypel
/ MWpel)]
or
[1,000,000 x X x VP/ 760]
ppm
Cm
Mass concentration of chemical in
air
Cvx MW/Vm
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-
day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-
day
APDR
Acute potential dose rate
l/BW
mg/kg-
day
Model Input Parameters and Default Values
The OSHA PEL-Limiting Model for Substance-Specific Vapor (TWA or C) default values for each of
the input parameters are summarized in Table B-4.
289
-------
ChemSTEER User Guide - Updated May 2015
Table B-4. Input Parameters and Default Values for the OSHA PEL-Limiting Model for Substance-
Specific Vapor (TWA or C)
Parameter
Description
Default Value(s)
Units
Cvk
Vapor concentration of the
chemical with a PEL in air
(based on OSHA PEL - TWA)
User-defined Cvk1
ppm
VP
Vapor pressure of the pure
chemical being assessed (0 <
VP)
VP
(from the associated vapor generation model2 or
VPchem in the Chemical tab)
torr
Ys
Weight fraction of the
chemical in mixture3
Defaults specified in Table B-4a
dimensionless
MW
Molecular weight of the
chemical (0 < MW)
MW
(from Chemical tab)
g/mol
VPpel
Vapor pressure of the pure
PEL chemical
User-defined VPpel1
torr
Ypel
Weight fraction of chemical
with PEL in mixture3
1 - Ys
dimensionless
MWpel
Molecular weight of the PEL
chemical
User-defined MWpel1
g/mol
X
Vapor pressure correction
factor (mole fraction or other
(0 < X < 1)
X
(from the associated vapor generation model2 or
from the Shared Parameters/Factors subtab -
Defaults specified in Table 19-b)
dimensionless
Vm
Molar volume (0 < Vm)
24.45 @ 25°C, 1 atm
L/mol
b
Volumetric inhalation rate (0
< b < 7.9)
1.25
m3/hr
h
Exposure duration (0 < h <
24)
8
hrs/day
NWexp
Number of workers exposed
while performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
site(s)
ED
Days exposed per year (0 <
ED (integer) < 365)
Defaults specified in Table B-4c
days/site-yr
EY
Years of occupational
exposure (0 < EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a
lifetime (chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT <
ATc)
EY
years
290
-------
ChemSTEER User Guide - Updated May 2015
1. You must select and manually input values of the OSHA PEL for the appropriate chemical, its molecular weight,
and its vapor pressure. In future versions of ChemSTEER, the user will choose a chemical from a pick list of OSHA
PEL chemicals from the Occupational Safety and Health Administration General Industry Air Contaminants
Standard (29 CFR 1910.1000.), and ChemSTEER will automatically retrieve the Cvk, molecular weight, and vapor
pressure for the PEL chemical. ChemSTEER contains a list of various OSHA PELS, as well as NIOSH Recommended
Exposure Limits (RELs), for more than 700 chemicals and other substances. You may view this list by clicking on the
View/Update Exposure Limits button, found on the Chemicals tab. To read more about this list, go to the List of
OSHA PELS and NIOSH RELs topic.
2. See Table B-4d for the hierarchy of logic for extracting VP, X, and ED values from an associated release model.
3. Rather than using the specified weight fractions Ys and Ypel, you may also choose to enter relative mass values
where Ys would be a relative weight of the chemical assessed and Ypel would be a relative weight of the substance
with a PEL. For example, if in some total mixture there are 150 kg of chemical assessed for every 50 kg of
substance with a PEL, any ratio of Ys: Ypel of 3 is valid. An option would be for you to enter 0.15 for Ys and 0.05 for
Ypel. Another option would be for you to enter 0.3 for Ys and 0.1 for Ypel.
You may elect to change any parameter from Table B-4, except when h is a constant for a PEL
that is based upon a specific TWA. The value of h may be changed when the PEL is a ceiling. Clicking the
Type column for each changeable parameter other than Cvk, Ys, VPpel, MWpel, X, and ED contains only
two options: ChemSTEER defaults from Table B-4 and User-defined. You must enter values for Cvk,
VPpel, and MWpel in this exposure model. The conditional default and non-default options for Ys, X, and
ED are presented in the tables below. Be sure to read the ChemSTEER Estimation Methods and Models
topic for more information about changing model parameters.
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Upper Bound
Default Characterization of Output 2 Results: Upper Bound
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"OSHA PEL-Limiting Model for Substance-Specific Vapor (TWA or C)"
291
-------
ChemSTEER User Guide - Updated May 2015
Table B-4a. Conditional Default Values for Ys for the OSHA PEL-Limiting Model for Substance-Specific
Vapor (TWA or C)
Source / Activity Type / Material
Names in Source/Activity Type
Operation
Type
Conditional Ys Default
Non-default
Options for Ys*
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtabs of the Operation Parameters
tab)
Yrm
Yprod
User-defined Ys
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
Not Container-Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined Ys
Not Container-Related
/Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined Ys
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
*Non-default options for Ys are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
292
-------
ChemSTEER User Guide - Updated May 2015
Table B-4b. Conditional Default Values for X for the OSHA PEL-Limiting Model for Substance-Specific
Vapor (TWA or C)
Associated Vapor
Generation Model*
Material named in
Source/Activity
Label
Operation
Type
Conditional X Default
Non-Default
Options for
X**
Yes
Any
Any
X
(from associated vapor
generation model* in the
Releases tab)
Xrm
Xprod
Xother
User-
defined X
No
or The associated vapor
generation model does
not contain an X value
Raw Material
Any
Xrm
(from Shared
Parameters/Factors subtab)
Xprod
Xother
User-
defined X
Product
Any
Xprod
(from Shared
Parameters/Factors subtab)
Xrm
Xother
User-
defined X
Other
Any
Xother
(from Shared
Parameters/Factors subtab)
Xrm
Xother
User-
defined X
Not material-specific
Manufacturing
Xprod
(from Shared
Parameters/Factors subtab)
Xrm
Xother
User-
defined X
Processing
Use
Xrm
(from Shared
Parameters/Factors subtab)
Xprod
Xother
User-
defined X
*See Table B-4d for the hierarchy of logic for extracting an X value from an associated release model.
**Non-default options for X are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
293
-------
ChemSTEER User Guide - Updated May 2015
Table B-4c. Conditional Default Values for ED for the OSHA PEL-Limiting Model for Substance-Specific
Vapor (TWA or C)
Associated Release Model /
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default (days
of exposure/site-yr)
Non-default
Options for
ED**
Yes
/ Container-related
/ Continuous
Not applicable
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
OD (days/site-
yr)
ODa (days/site-
yr)
User-defined
ED
Yes
/ Container-related
/ Batch
Any
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
Nby (bt/site-yr)
OD (days/site-
yr)
ODa (days/site-
yr)
User-defined
ED
Yes
/ Not Container-related
/ Continuous
Not applicable
Lesser of 250 or Freq from
associated release model*
(from Release tab)
OD (days/site-
yr)
User-defined
ED
Yes
/ Not Container-related
/ Batch
Any
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
Nby (bt/site-yr)
OD (days/site-
yr)
User-defined
ED
No associated release model
/ Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operations
Parameters tab)
OD (das/site-yr)
User-defined
ED
No associated release model
/Container-Related
/Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operations
Parameters tab)
Nby (bt/site-yr)
OD (days/st-yr)
User-defined
ED
No associated release model
/ Not Container-Related
/Continuous
Not applicable
Lesser of 250 or OD
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
User-defined
ED
No associated release model
/ Not Container-Related
/ Batch
Number of batches per day
(Nbd)< 1
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
Lesser of 250 or Nby
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
OD (days/site-
yr)
User-defined
ED
Number of batches per day
(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
Lesser of 250 or OD
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
Nby (bt/site-yr)
User-defined
ED
294
-------
ChemSTEER User Guide - Updated May 2015
*See Table B-4d for the hierarchy of logic for extracting an ED value from an associated release model.
**Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Table B-4d. Hierarchy for Extracting Parameter Defaults from Associated Release Models* for the
OSHA PEL-Limiting Model for Substance-Specific Vapor (TWA or C)
1. Use current value of parameter from the last associated vapor generation model* for the source/activity
(from the Releases tab).
2. Use current value of parameter from the last associated release model* for the source/activity (from the
Releases tab) - only if there is no associated vapor generation model.
3. If no associated release model* for the source/activity, then use conditional default as described for "No
associated release model" in Tables B-4, and B-4b, and B-4c above.
*The associated release model is the LAST vapor generation or release model that contains a parameter value
required for the OSHA PEL-Limiting Model for Substance Specific Vapor that is listed in the Release Model(s)for
Selected Activity box in the Releases tab (i.e., it is the last vapor generation or release model that was added by
either ChemSTEER or the user) for the selected Source/Activity.
When extracting parameter values from the Releases tab, the OSHA PEL-Limiting Model for
Substance-Specific Vapors Input Parameters for Output 1 are obtained from the associated release
model Input Parameters for Output 1; and the OSHA PEL-Limiting Model for Substance-Specific Vapors
Input Parameters for Output 2 are obtained from the associated release model Input Parameters for
Output 2.
Key Rationale for Model
Operations are generally expected to comply with OSHA's federal regulation regarding
inhalation of specific chemicals. This model assumes that the exposure concentration of the chemical is
at a ratio such that the concentration of the substance with a PEL is not exceeded.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-1, 4-4)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
a T-i riRi/iri nr:»r i u, i ... i
Model Description
This model estimates the amount of chemical inhaled by a worker during handling of solid/
powdered materials containing the chemical. The estimate assumes that the worker is exposed at a level
no greater than the OSHA Permissible Exposure Limit (PEL) for Particulate, Not Otherwise Regulated
(PNOR), total particulate.
295
-------
ChemSTEER User Guide - Updated May 2015
Sources/Activities That Use This Model as a Default
The OSHA Total PNOR PEL-Limiting Model is the default for calculating worker inhalation
exposures to a chemical while performing the following sources/activities:
• Grinding and Sanding
• Coating Using Hand Held Spray Gun
Other Sources/Activities
The OSHA Total PNOR PEL-Limiting Model may be an appropriate alternative to the default
inhalation model for the following sources/activities:
Where the amount of material being handled is more than 54 kg/day (or where the amount of
material is unknown or was not previously calculated):
• All sources/activities for Cleaning Solid Residuals from Transport Containers/Vessels
• All sources/activities for Loading Solids into Transport Containers/Vessels
• All sources/activities for Vessels
• Equipment Cleaning Losses of Solids
• Miscellaneous Sources/Activities Related to Solid Processing
This model may be also used for the following sources/activities, regardless of the amount of
material:
• All sources/activities for Sampling Solids
• Miscellaneous Sources/Activities Related to Liquid Processing
• Filter Media Changeout
• Roll Coating
Potential Route / Form(s) of Exposure
Inhalation / Particulate or non-volatile portion of mist, aerosols, etc.
Equations
Parameters
Description
Equation
Units
Cm
Mass concentration of chemical in air
KCk x Ys
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
296
-------
ChemSTEER User Guide - Updated May 2015
Model Input Parameters and Default Values
The OSHA Total PNOR PEL-Limiting Model default values for each of the input parameters are
summarized in Table B-5.
Table B-5. Input Parameters and Default Values for the OSHA Total PNOR PEL-Limiting Model
Parameter
Description
Default Value(s)
Units
KCk
Mass concentration of total particulate in air
(based on OSHA PEL for PNOR - TWA)
15
mg/ m3
Ys
Weight fraction of the chemical in
particulate (or in solids portion of mist, etc.)
(0 < Ys < 1)
Defaults specified in Table B-5a
dimensionless
b
Volumetric inhalation rate (0 < b < 7.9)
1.25
m3/hr
h
Exposure duration (0 < h < 24)
8
hrs/day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
site(s)
ED
Days exposed per year (0 < ED (integer) <
365)
Defaults specified in Table B-5c
days/site-yr
EY
Years of occupational exposure (0 < EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime (chronic) (0 <
ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-5 except KCk and h, which are constants.
Clicking the Type column for each changeable parameter other than KCk, h, Ys and ED contains only two
options: ChemSTEER defaults from Table B-5 and User-defined. The conditional default and non-default
options for Ys and ED are presented in the tables below. Be sure to read the ChemSTEER Estimation
Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameters, KCk and h, to be anything other than the
defaults shown above. If you wish to model inhalation exposures to solids using your own PEL data,
choose the OSHA PEL-Limiting Model for Substance-Specific Particulates.
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization:
297
-------
ChemSTEER User Guide - Updated May 2015
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Upper Bound
Default Characterization of Output 2 Results: Upper Bound
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"OSHA PNOR PEL-Limiting Model"
Table B-5a. Conditional Default Values for Ys for the OSHA Total PNOR PEL-Limiting Model
Source / Activity Type / Material
Names in Source/Activity Type
Operation
Type
Conditional Ys Default
Non-default
Options for Ys*
Sources/Activities Handling Solids
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtabs of the Operation Parameters
tab)
Yrm
Yprod
User-defined Ys
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
Not Container-Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined Ys
Not Container-Related
/Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined Ys
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
Sources/Activities Handling Liquids and Unspecified Materials
Container-Related
/Any
Not applicable
User-defined Ys
Yi
Yrm
Yprod
Not Container-Related
/Any
Not applicable
User-defined Ys
Yrm
Yprod
*Non-default options for Ys are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
298
-------
ChemSTEER User Guide - Updated May 2015
Table B-5b. Conditional Default Values for ED for the OSHA Total PNOR PEL-Limiting Model
Source/ Activity
Type/ Operation
Mode
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED*
Container-Related /
Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-
yr)
User-defined ED
Container-Related /
Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-
yr)
User-defined ED
Not Container-
Related / Continuous
Not Applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-
Related / Batch
Number of batches per day
(Nbd)< 1
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per day
(Nbd)> 1
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Key Rationale for Model
Operations are generally expected to comply with OSHA's federal regulation regarding total
particulate exposures. This model assumes that the exposure concentration is the same as the
concentration of the chemical in the mixture.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-1, 4-11)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
OSHA Respirable PNOR PEL-Limiting Model
Model Description
This model estimates the amount of chemical inhaled by a worker during handling of solid/
powdered materials containing the chemical. The estimate assumes that the worker is exposed at a level
299
-------
ChemSTEER User Guide - Updated May 2015
no greater than the OSHA Permissible Exposure Limit (PEL) for Particulate, Not Otherwise Regulated
(PNOR), respirable particulate.
Sources/Activities That Use This Model as a Default
There are no sources/activities in ChemSTEER that use this model as a default for calculating
worker inhalation exposures to a chemical.
Other Sources/Activities
The OSHA Respirable PNOR PEL-Limiting Model may also be an appropriate means to calculate
worker inhalation exposures to a solid, particulate chemical while performing the following
sources/activities:
• All sources/activities for Cleaning Solid Residuals from Transport Containers/Vessels
• All sources/activities for Loading Solids into Transport Containers/Vessels
• All sources/activities for Unloading Solids from Transport Containers/Vessels
• All sources/activities for Sampling Solids
• Equipment Cleaning Losses of Solids
• Miscellaneous Sources/Activities Related to Liquid Processing
• Miscellaneous Sources/Activities Related to Solid Processing
• Filter Media Changeout
• Grinding and Sanding
• Roll Coating
Potential Route / Form(s) of Exposure
Inhalation / Particulate or non-volatile portion of mist, aerosols, etc.
Equations
Parameters
Description
Equation
Units
Cm
Mass concentration of chemical in air
KCk x Ys
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
Model Input Parameters and Default Values
The OSHA Respirable PNOR PEL-Limiting Model default values for each of the input parameters
are summarized in Table B-6.
300
-------
ChemSTEER User Guide - Updated May 2015
Table B-6. Input Parameters and Default Values for the OSHA Respirable PNOR PEL-Limiting Model
Parameter
Description
Default Value(s)
Units
KCk
Mass concentration of total particulate in air
(based on OSHA PEL for PNOR - TWA)
5
mg/ m3
Ys
Weight fraction of the chemical in
particulate (or in solids portion of mist, etc.)
(0 < Ys < 1)
Defaults specified in Table B-6a
dimensionless
b
Volumetric inhalation rate (0 < b < 7.9)
1.25
m3/hr
h
Exposure duration (0 < h < 24)
8
hrs/day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
site(s)
ED
Days exposed per year (0 < ED (integer) <
365)
Defaults specified in Table B-4c
days/site-yr
EY
Years of occupational exposure (0 < EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime (chronic) (0 <
ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-6 except KCk and h, which are constants.
Clicking the Type column for each changeable parameter other than KCk, h, Ys and ED contains only two
options: ChemSTEER defaults from Table B-6 and User-defined. The conditional default and non-default
options for Ys and ED are presented in the tables below. Be sure to read the ChemSTEER Estimation
Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameters, KCk and h, to be anything other than the
defaults shown above. If you wish to model inhalation exposures to solids using your own PEL data,
choose the OSHA PEL-Limiting Model for Substance-Specific Particulates.
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Upper Bound
Default Characterization of Output 2 Results: Upper Bound
301
-------
ChemSTEER User Guide - Updated May 2015
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"OSHA Respirable PNOR PEL-Limiting Model"
Table B-6a. Conditional Default Values for Ys for the OSHA Respirable PNOR PEL-Limiting Model
Source / Activity Type / Material
Names in Source/Activity Type
Operation
Type
Conditional Ys Default
Non-default
Options for Ys*
Sources/Activities Handling Solids
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtabs of the Operation Parameters
tab)
Yrm
Yprod
User-defined Ys
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
Not Container-Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined Ys
Not Container-Related
/Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined Ys
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined Ys
Sources/Activities Handling Liquids and Unspecified Materials
Container-Related
/Any
Not applicable
User-defined Ys
Yi
Yrm
Yprod
Not Container-Related
/Any
Not applicable
User-defined Ys
Yrm
Yprod
*Non-default options for Ys are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
302
-------
ChemSTEER User Guide - Updated May 2015
Table B-6b. Conditional Default Values for ED for the OSHA Respirable PNOR PEL-Limiting Model
Source/ Activity
Type/ Operation
Mode
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED*
Container-Related /
Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-
yr)
User-defined ED
Container-Related /
Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-
yr)
User-defined ED
Not Container-
Related / Continuous
Not Applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-
Related / Batch
Number of batches per day
(Nbd)< 1
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per day
(Nbd)> 1
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Key Rationale for Model
Operations are generally expected to comply with OSHA's federal regulation regarding
respirable particulate exposures. This model assumes that the exposure concentration is the same as
the concentration of the chemical in the mixture.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-1, 4-11)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
EPA/OPPTAutomobile OEM Spray Coating Inhalation Exposure Model
Model Description
303
-------
ChemSTEER User Guide - Updated May 2015
This model estimates the amount of non-volatile non-polyisocyanate chemical in mist inhaled by
a worker spray painting automobiles in automobile OEM coating operations. This model uses mist
concentration data based upon spray gun type and booth type.
Sources/Activities That Use This Model as a Default
The EPA/OPPT Automobile OEM Spray Coating Inhalation Exposure Model (non-volatile, non-
polyisocyanates) is the default for calculating worker exposures to a non-volatile, non-polyisocyanate
chemical during the Automobile OEM Spray Coating Application source/activity.
This model is not used as an alternative inhalation exposure model for any other
sources/activities.
Potential Route / Form(s) of Exposure
Inhalation / Particulate or non-volatile portion of mist, aerosols, etc.
Equations
Parameters
Description
Equation
Units
Cm
Mass concentration of chemical in air
KCk x Ys
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
Model Input Parameters and Default Values
The EPA/OPPT Automobile OEM Spray Coating Inhalation Exposure Model default values for
each of the input parameters are summarized in Table B-7.
304
-------
ChemSTEER User Guide - Updated May 2015
Table B-7. Input Parameters and Default Values for the EPA/OPPT Automobile OEM Spray Coating
Inhalation Exposure Model (non-volatile non-polyisocyanates)
Parameter
Description
Default Value(s)
Units
KCk
Mass concentration of total particulate in
air
Non-default options specified in Table
B-7a
mg/ m3
Ys
Weight fraction of the chemical in
particulate or solids fraction of mist (0 < Ys
<1)
Lesser of (Ymist/Ysf) or 1
or User-defined Ys
dimensionless
Ymist
Weight fraction of chemical in mist (0 <
Ymist < 1)
Non-default options specified in Table
B-7b
dimensionless
Ysf
Weight fraction of solids in paint (0 < Ysf <
1)
0.25*
dimensionless
b
Volumetric inhalation rate (0 < b < 7.9)
1.25
m3/hr
h
Exposure duration (0 < h < 24)
8
hrs/day
NWexp
Number of workers exposed while
performing the activity
17
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
site(s)
ED
Days exposed per year (0 < ED (integer) <
365)
Defaults specified in Table B-7c
days/site-yr
EY
Years of occupational exposure (0 < EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime (chronic) (0
< ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
*The reference generic scenario suggests a default solids fraction of 0.25. It also states that "'high solids paint' for
automobiles can have a solids content of up to 45 to 50 volume percent to top coats...; however, solids content
varies widely."
You may elect to change any parameter from Table B-7. If you input a user-defined value for Ys,
the values of Ymist and Ysf are not used in the model. Clicking the Type column for each changeable
parameter other than KCk, Ymist, and ED contains only two options: ChemSTEER defaults from Table B-7
and User-defined. The conditional default and non-default options for KCk, Ymist, and ED are presented
in the tables below. Be sure to read the ChemSTEER Estimation Methods and Models topic for more
information about changing model parameters.
You may not change the defining model parameter, KCk, to be anything other than the default
shown in Table B-7a. If you wish to model inhalation exposures to mists using your own concentration
data, choose the User-Defined Inhalation Model or the OSHA PEL-Limiting Model for Substance-Specific
Particulates.
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
305
-------
ChemSTEER User Guide - Updated May 2015
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterization for Output 1: What-lf
Default characterization for Output 2: What-lf
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT Automobile OEM Spray Coating Inhalation Model (non-volatile non-
polyisocyanates)"
Table B-7a. KCk for the EPA/OPPT Automobile OEM Spray Coating Inhalation Exposure Model (non-
volatile non-
polyisocyanates)
Spray Gun Type (from the Shared
Parameters/Factors subtab of the Operation
Parameters tab)
KCk Default (mg/m3)
(Origin Label)
Non-Default Options for KCk1
(Origin Label)
Conventional2
2.3 (Conv/Downdraft)
15 (Conv/Crossdraft)
15 (HVLP/Crossdraft)
1.9 (HVLP/Downdraft)
HVLP
1.9 (HVLP/Downdraft)
15 (HVLP/Crossdraft)
15 (Conv/Crossdraft)
2.3 (Conv/Downdraft)
1. The non-default options for KCk may be selected at the model level. If the value for KCk is changed in the
Exposures tab, the new value will only be used in the calculations performed by the model for the selected
exposure activity. The spray gun type shared parameter will not be updated in the Shared Parameters/Factors
subtab if an alternative KCk value is chosen in the Exposures tab.
2. Conventional spray guns are selected as the default for the Automobile OEM Spray Coating operation in the
Shared Parameters/Factors subtab. The conventional spray gun default for the Automobile OEM Spray Coating
Operation was adopted as an internal policy decision in July 2003. This setting is also the default for all non-
automobile spray coating operations (i.e., the User-Defined operations).
306
-------
ChemSTEER User Guide - Updated May 2015
Table B-7b. Conditional Default Values for Ymist for the EPA/OPPT Automobile OEM Spray Coating
Inhalation Exposure Model (non-volatile non-polyisocyanates)
Operation
Ymist Default*
Non-default Options for
Ymist**
Automobile OEM Spray
Coating
Yfpaint
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yrm
User-defined Ymist
Automobile Refinish Spray
Coating
Yfpaint
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yppaint
User-defined Ymist
Not Automobile Spray
Coating
Yprod
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yrm
User-defined Ymist
*The default value for Ymist in all cases is the weight fraction of the chemical in the sprayed coating. Yfpaint and
Yprod are synonymous to the weight fraction of chemical contained in the product, in its final formulation and as
sprayed. Yfpaint is used in the Automobile Spray Coating Operations and Yprod is used by all user-defined
operations.
**Non-default options for Ymist are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. Yrm and Yppaint are synonymous to the weight fraction of the chemical
contained in the raw material or coating, as purchased in its initial formulation. Yrm is used in the Automobile OEM
Spray Coating Operation, as well as all user-defined operations; Yppaint is used in the Automobile Refinish Spray
Coating Operation.
If you enter a User-defined Ymist or Ysf (0 < Ymist < 1, 0 < Ysf < 1) and the value is not valid,
ChemSTEER will display a pop-up message warning you that the choice is invalid. You must enter a value
that will result in a valid Ymist or Ysf before ChemSTEER will allow you to move on from the selection
process.
Table B-7c. Conditional Default Values for ED for the EPA/OPPT Automobile OEM Spray Coating
Inhalation Exposure Model (non-volatile non-polyisocyanates)
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED*
Continuous
Lesser of 250 or OD
(from Mass Balance subtab of the Operation
Parameters tab)
User-defined ED
Batch
Number of batches per day (Nbd) < 1
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
Lesser of 250 or Nby
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
OD (days/site-yr)
User-defined ED
Batch
Number of batches per day (Nbd) > 1
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
Lesser of 250 or OD
(from the Mass Balance Parameters subtab of
the Operation Parameters tab)
Nby (bt/site-yr)
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Key Rationale for Model
307
-------
ChemSTEER User Guide - Updated May 2015
Midpoint sampling period TWA values for particulate from several monitoring studies of
workers in conditions using the variety of controls noted.
References
SAIC for US EPA/OPPT/CEB. Generic Scenario for Automobile Spray Coating Draft Report. August
1996.
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-1, 4-11)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
EPA/OPPTAutomobile Refinish Spray Coating Inhalation Exposure Model
Model Description
This model estimates the amount of non-volatile non-polyisocyanate chemical in mist inhaled by
a worker spray painting automobiles in automobile refinish coating operations. This model uses mist
concentration data primarily based upon the booth type.
Sources/Activities That Use This Model as a Default
The EPA/OPPT Automobile Refinish Spray Coating Inhalation Exposure Model (non-volatile, non-
polyisocyanates) is the default for calculating worker exposures to a non-volatile, non-polyisocyanate
chemical during the Automobile Refinish Spray Coating Application source/activity.
This model is not used as an alternative inhalation exposure model for any other
sources/activities.
Potential Route / Form(s) of Exposure
Inhalation / Particulate or non-volatile portion of mist, aerosols, etc.
Equations
Parameters
Description
Equation
Units
Cm
Mass concentration of chemical in air
KCk x Ys
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
Model Input Parameters and Default Values
308
-------
ChemSTEER User Guide - Updated May 2015
The EPA/OPPT Automobile Refinish Spray Coating Inhalation Exposure Model default values for
each of the input parameters are summarized in Table B-8.
Table B-8. Input Parameters and Default Values for the EPA/OPPT Automobile Refinish Spray Coating
Inhalation Exposure Model (non-volatile non-polyisocyanates)
Parameter
Description
Default Value(s)
Units
KCk
Mass concentration of total particulate in
air
Non-default options specified in Table
B-8a
mg/ m3
Ys
Weight fraction of the chemical in
particulate or solids fraction of mist (0 < Ys
<1)
Lesser of (Ymist/Ysf) or 1
or User-defined Ys
dimensionless
Ymist
Weight fraction of chemical in mist (0 <
Ymist < 1)
Non-default options specified in Table
B-8b
dimensionless
Ysf
Weight fraction of solids in paint (0 < Ysf <
1)
0.25*
dimensionless
b
Volumetric inhalation rate (0 < b < 7.9)
1.25
m3/hr
h
Exposure duration (0 < h < 24)
2.35
hrs/day
NWexp
Number of workers exposed while
performing the activity
3
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
site(s)
ED
Days exposed per year (0 < ED (integer) <
365)
Defaults specified in Table B-8c
days/site-yr
EY
Years of occupational exposure (0 < EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime (chronic) (0
< ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
*The reference generic scenario suggests a default solids fraction of 0.25. It also states that "'high solids paint' for
automobiles can have a solids content of up to 45 to 50 volume percent to top coats...; however, solids content
varies widely."
You may elect to change any parameter from Table B-8. If you input a user-defined value for Ys,
the values of Ymist and Ysf are not used in the model. Clicking the Type column for each changeable
parameter other than KCk, Ymist, and ED contains only two options: ChemSTEER defaults from Table B-8
and User-defined. The conditional default and non-default options for KCk, Ymist, and ED are presented
in the tables below. Be sure to read the ChemSTEER Estimation Methods and Models topic for more
information about changing model parameters.
You may not change the defining model parameter, KCk, to be anything other than the defaults
shown in Table B-8 and Table B-8a, respectively. If you wish to model inhalation exposures to mists
using your own concentration data, choose the User-Defined Inhalation Model or the OSHA PEL-Limiting
Model for Substance-Specific Particulates.
309
-------
ChemSTEER User Guide - Updated May 2015
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default characterization for Output 1: High-End
Default characterization for Output 2: High-End
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT Automobile Refinish Spray Coating Inhalation Model (non-volatile non-
polyisocyanates)"
Table B-8a. KCk for the EPA/OPPT Automobile Refinish Spray Coating Inhalation Exposure Model (non-
volatile non-
polyisocyanates)
Spray Gun Type (from the Shared
Parameters/Factors subtab of the Operation
Parameters tab)
KCk Default (mg/m3)
(Origin Label)
Non-Default Options for
KCk1
(Origin Label)
Conventional2
32 (High End/Crossdraft)
9 (Typical/Crossdraft)
7 (High End/Downdraft)
1 (Typical/Downdraft)
HVLP
32 (High End/Crossdraft)
9 (Typical/Crossdraft)
7 (High End/Downdraft)
1 (Typical/Downdraft)
1. The non-default options for KCk mav be selected at the model level. If the value for KCk is changed in the
Exposures tab, the new value will only be used in the calculations performed by the model for the selected
exposure activity. The spray gun type shared parameter will not be updated in the Shared Parameters/Factors
subtab if an alternative KCk value is chosen in the Exposures tab.
2. Conventional spray guns are selected as the default for the Automobile Refinish Spray Coating operation in the
Shared Parameters/Factors subtab. This setting is also the default for all non-automobile spray coating operations
(i.e., the User-Defined operations).
310
-------
ChemSTEER User Guide - Updated May 2015
Table B-8b. Conditional Default Values for Ymist for the EPA/OPPT Automobile Refinish Spray Coating
Inhalation Exposure Model (non-volatile non-polyisocyanates)
Operation
Ymist Default*
Non-default Options for
Ymist**
Automobile Refinish Spray
Coating
Yfpaint
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yppaint
User-defined Ymist
Automobile OEM Spray
Coating
Yfpaint
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yrm
User-defined Ymist
Not Automobile Spray
Coating
Yprod
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yrm
User-defined Ymist
*The default value for Ymist in all cases is the weight fraction of the chemical in the sprayed coating. Yfpaint and
Yprod are synonymous to the weight fraction of chemical contained in the product, in its final formulation and as
sprayed. Yfpaint is used in the Automobile Spray Coating Operations and Yprod is used by all user-defined
operations.
**Non-default options for Ymist are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. Yrm and Yppaint are synonymous to the weight fraction of the chemical
contained in the raw material or coating, as purchased in its initial formulation. Yrm is used in the Automobile OEM
Spray Coating Operation, as well as all user-defined operations; Yppaint is used in the Automobile Refinish Spray
Coating Operation.
If you enter a User-defined Ymist or Ysf (0 < Ymist < 1, 0 < Ysf < 1) and the value is not valid,
ChemSTEER will display a pop-up message warning you that the choice is invalid. You must enter a value
that will result in a valid Ymist or Ysf before ChemSTEER will allow you to move on from the selection
process.
Table B-8c. Conditional Default Values for ED for the EPA/OPPT Automobile Refinish Spray Coating
Inhalation Exposure Model (non-volatile non-polyisocyanates)
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED*
Continuous
Lesser of 250 or OD
(from Mass Balance subtab of the Operation
Parameters tab)
User-defined ED
Batch
Number of batches per day (Nbd) < 1
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
Lesser of 250 or Nby
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
OD (days/site-yr)
User-defined ED
Batch
Number of batches per day (Nbd) > 1
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
Lesser of 250 or OD
(from the Mass Balance Parameters subtab of
the Operation Parameters tab)
Nby (bt/site-yr)
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Key Rationale for Model
311
-------
ChemSTEER User Guide - Updated May 2015
Midpoint sampling period TWA values for particulate from several monitoring studies of
workers in conditions using the variety of controls noted.
References
Organization for Economic Co-operation and Development. Emission Scenario Document on
Coating Application via Spray Painting in the Automotive Refinishing Industry. June 2010.
Chemical Engineering Branch Manual for the Preparation of Engineering Assessments,
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991.
(Equations 4-1, 4_11)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
EPA/OPPTAutomobile Spray Coating Inhalation Exposure Model
Model Description
This model estimates the amount of polyisocyanate chemical in mist inhaled by a worker spray
painting automobiles or similar applications. This model uses mist concentration data based upon
conventional spray guns used in crossdraft booths by default.
Sources/Activities That Use This Model as a Default
There are no sources/activities in ChemSTEER that use this model as a default for calculating
worker inhalation exposures to a chemical.
Other Sources/Activities
The EPA/OPPT Automobile Spray Coating Inhalation Exposure Model (non-volatile
polyisocyanates) Model may be an appropriate means to calculate worker inhalation exposures to a
non-volatile polyisocyante chemical while performing either of the Automobile Spray Coating
sources/activities.
Potential Route / Form(s) of Exposure
Inhalation / Particulate or non-volatile portion of mist, aerosols, etc.
Equations
Parameters
Description
Equation
Units
Cm
Mass concentration of chemical in air
KCk
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
312
-------
ChemSTEER User Guide - Updated May 2015
Model Input Parameters and Default Values
The EPA/OPPT Automobile Spray Coating Inhalation Exposure Model (polyisocyanates) default
values for each of the input parameters are summarized in Table B-9.
Table B-9. Input Parameters and Default Values for the EPA/OPPT Automobile Spray Coating
Inhalation Exposure Model (polyisocyanates)
Parameter
Description
Default Value(s)
Units
KCk
Mass concentration of total
particulate in air
Non-default options specified in Table B-9a
mg/ m3
b
Volumetric inhalation rate (0 < b <
7.9)
1.25
m3/hr
h
Exposure duration (0 < h < 24)
8
hrs/day
NWexp
Number of workers exposed while
performing the activity
3
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
site(s)
ED
Days exposed per year (0 < ED
(integer) < 365)
Defaults specified in Table B-4c
days/site-yr
EY
Years of occupational exposure (0 <
EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime
(chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-9. Clicking the Type column for each
changeable parameter other than KCk and ED contains only two options: ChemSTEER defaults from
Table B-9 and User-defined. The conditional default and non-default options for KCk and ED are
presented in the tables below. Be sure to read the ChemSTEER Estimation Methods and Models topic
for more information about changing model parameters.
You may not change the defining model parameter, KCk, to be anything other than the default
shown in Table B-9a. If you wish to model inhalation exposures to mists using your own concentration
data, choose the User-Defined Inhalation Model or the OSHA PEL-Limiting Model for Substance-Specific
Particulates.
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Enabled
313
-------
ChemSTEER User Guide - Updated May 2015
Enable Model Parameters for Output 2: Enabled
Default characterization for Output 1: What-lf
Default characterization for Output 2: What-lf
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT Automobile Spray Coating Inhalation Model (non-volatile polyisocyanates)"
Table B-9a. KCk Options for the EPA/OPPT Automobile Spray Coating Inhalation Exposure Model
(polyisocyanates)
Spray Gun Type
(from the Shared
Parameters/Factors subtab
of the Operation
Parameters tab)
KCk Default (mg/m3)
(Origin Label)
Non-Default Options for KCk1
(Origin Label)
Origin Label
Output
1
Output
2
Selection/Origin
Label
Output
1
Output
2
Conventional2
Conv/Crossdraft
0.05
18.4
HVLP/Crossdraft
Conv/ Downdraft
HVLP/Downdraft
1.0
0.01
0.6
5.2
3.7
1.4
HVLP
HVLP/Crossdraft
1.0
5.2
Conv/Crossdraft
Conv/Downdraft
HVLP/Downdraft
0.05
0.01
0.6
18.4
3.7
1.4
1. The non-default options for KCk may be selected at the model level. If the value for KCk is changed in the
Exposures tab, the new value will only be used in the calculations performed by the model for the selected
exposure activity. The spray gun type shared parameter will not be updated in the Shared Parameters/Factors
subtab if an alternative KCk value is chosen in the Exposures tab.
2. The Shared Parameters/Factors subtab defaults to the conventional spray gun for all operations (Auto Spray
Coating and User-defined).
314
-------
ChemSTEER User Guide - Updated May 2015
Table B-9b. Conditional Default Values for ED for the EPA/OPPT Automobile Spray Coating Inhalation
Exposure Model (polyisocyanates)
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED*
Continuous
Lesser of 250 or OD
(from Mass Balance subtab of the Operation
Parameters tab)
User-defined ED
Batch
Number of batches per day (Nbd) < 1
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
Lesser of 250 or Nby
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
OD (days/site-yr)
User-defined ED
Batch
Number of batches per day (Nbd) > 1
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
Lesser of 250 or OD
(from the Mass Balance Parameters subtab of
the Operation Parameters tab)
Nby (bt/site-yr)
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Key Rationale for Model
Measured or estimated concentration ranges for particulate from several monitoring studies of
workers in conditions using the variety of controls noted.
References
SAIC for US EPA/OPPT/CEB. Generic Scenario for Automobile Spray Coating Draft Report. August
1996.
Chemical Engineering Branch Manual for the Preparation of Engineering Assessments,
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991.
(Equations 4-1, 4-11)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
EPA/OPPT UVRoll Coating Inhalation Model
Model Description
This model estimates the amount of chemical inhaled by a worker who conducts activities near
roll coater(s) using coatings or inks containing the chemical.
Sources/Activities That Use This Model as a Default
The EPA/OPPT UV Roll Coating Inhalation Model is the default for calculating worker inhalation
exposures to a chemical while performing the Roll Coating source/activity.
Other Sources/Activities
315
-------
ChemSTEER User Guide - Updated May 2015
The EPA/OPPT UV Roll Coating Inhalation Model may be an appropriate alternative to the
default inhalation model for the following sources/activities:
• Miscellaneous Sources/Activities Related to Liquid Processing
• Miscellaneous Sources/Activities Related to Solid Processing
Potential Route / Form(s) of Exposure
Inhalation / Particulate or non-volatile portion of mist, aerosols, etc.
Equations
Parameters
Description
Equation
Units
Cm
Mass concentration of chemical in air
KCk x Ys
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
Model Input Parameters and Default Values
The EPA/OPPT UV Roll Coating Inhalation Model default values for each of the input parameters
are summarized in Table B-10.
316
-------
ChemSTEER User Guide - Updated May 2015
Table B-10. Input Parameters and Default Values for the EPA/OPPT UV Roll Coating Inhalation Model
Parameter
Description
Default Value(s)
Units
KCk
Mass concentration of total particulate or
nonvolatile portion of mist in air (based on
data)
Output 1:
Default: 0.04 (Low end of range)
Non-default Option: 0.26 (High end
of range)
mg/ m3
Output 2:
Default: 0.26 (High end of range)
Non-default Option: 0.04 (Low end
of range)
Ys
Weight fraction of chemical in particulate or
non-volatiles fraction of mist (0 < Ys < 1)
Lesser of (Ymist/Ysf) or 1
dimensionless
Ymist
Weight fraction of chemical in mist (0 <
Ymist < 1)
Non-default options specified in
Table B-lOa
dimensionless
Ysf
Weight fraction of solids in coating (0 < Ysf <
1)
0.25*
dimensionless
b
Volumetric inhalation rate (0 < b < 7.9)
1.25
m3/hr
h
Exposure duration (0 < h < 24)
8
hrs/day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
site(s)
ED
Days exposed per year (0 < ED (integer) <
365)
Defaults specified in Table B-lOb
days/site-yr
EY
Years of occupational exposure (0 < EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime (chronic) (0 <
ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
*The default solids (i.e., non-volatiles) fraction in this model is based on information contained in the 1996 Generic
Scenario for Automobile Spray Coating. This reference also states that "'high solids paint' for automobiles can have
a solids content of up to 45 to 50 volume percent to top coats...; however, solids content varies widely." Specific
data for UV/EB-curable roll coatings is not currently available. If you have data to suggest an alternative value, you
are encouraged to use it in the calculations.
You may elect to change any parameter from Table B-10 except KCk, which is a constant.
Clicking the Type column for each changeable parameter other than KCk, Ymist, and ED contains only
two options: ChemSTEER defaults from Table B-10 and User-defined. The conditional default and non-
default options for Ymist and ED are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
You may not change the defining model parameter, KCk, to be anything other than the default
shown in Table B-lOa. If you wish to model inhalation exposures to solids or mists using your own data
or based on OSHA PELs, choose one of the following alternative models:
317
-------
ChemSTEER User Guide - Updated May 2015
OSHA PEL-Limiting Model for Substance-Specific Particulates;
OSHA Total PNOR PEL-Limiting Model; or
User-Defined Inhalation Model.
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Low end of range
Default Characterization of Output 2 Results: High end of range
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT UV Roll Coating Inhalation Model (non-volatiles); airborne particulate
concentration (KCk) is based on 8-hour TWA personal monitoring data"
NOTE: If you click in the Basis text box and modify the default text, the dynamic text will no
longer function. You will be required to manually update the text box.
318
-------
ChemSTEER User Guide - Updated May 2015
Table B-lOa. Conditional Default Values for Ymist for the EPA/OPPT UV Roll Coating Inhalation Model
Operation
Ymist Default*
Non-default Options for
Ymist**
Automobile OEM Spray
Coating
Yfpaint
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yrm
User-defined Ymist
Automobile Refinish Spray
Coating
Yfpaint
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yppaint
User-defined Ymist
Not Automobile Spray
Coating
Yprod
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
Yrm
User-defined Ymist
*The default value for Ymist in all cases is the weight fraction of the chemical in the rolled coating or ink. Yfpaint
and Yprod are synonymous to the weight fraction of chemical contained in the product, in its final formulation and
as applied. Yfpaint is used in the Automobile Spray Coating Operations and Yprod is used by all user-defined
operations.
**Non-default options for Ymist are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. Yrm and Yppaint are synonymous to the weight fraction of the chemical
contained in the raw material or coating, as purchased in its initial formulation. Yrm is used in the Automobile OEM
Spray Coating Operation, as well as all user-defined operations; Yppaint is used in the Automobile Refinish Spray
Coating Operation.
If you enter a User-defined Ymist or Ysf (0 # Ymist # 1, 0 # Ysf # 1) and the value is not valid,
ChemSTEER will display a pop-up message warning you that the choice is invalid. You must enter a value
that will result in a valid Ymist or Ysf before ChemSTEER will allow you to move on from the selection
process.
Table B-lOb. Conditional Default Values for ED for the EPA/OPPT UV Roll Coating Inhalation Model
Batch Condition
Conditional ED Default
(days of exposure/site-yr)
Non-default
Options for ED*
Continuous
Lesser of 250 or OD
(from Mass Balance subtab of the Operation
Parameters tab)
User-defined ED
Batch
Number of batches per day (Nbd) < 1
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
Lesser of 250 or Nby
(from Mass Balance Parameters subtab of the
Operation Parameters tab)
OD (days/site-yr)
User-defined ED
Batch
Number of batches per day (Nbd) > 1
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
Lesser of 250 or OD
(from the Mass Balance Parameters subtab of
the Operation Parameters tab)
Nby (bt/site-yr)
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Key Rationale for Model
Limited personal samples from a monitoring study of workers in exposed to 'ink fly' in a facility
using offset lithographic printing of cartonboard using UV-curable ink, which may be applied to similar
319
-------
ChemSTEER User Guide - Updated May 2015
roll coating operations. This model assumes that the exposure concentration is the same as the
concentration of the chemical in the non-volatile portion of the coating mixture.
References
Chemical Engineering Branch Manual for the Preparation of Engineering Assessments,
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991.
(Equations 4-1, 4-11)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
SAIC for US EPA/OPPT/CEB. Generic Scenario for Automobile Spray Coating Draft Report. August
1996.
Generic Scenario: Roll Coating of UV-Curable Coatings. No date.
Near-Field/Far-Field Inhalation Exposure Model
Model Description
This model estimates inhalation exposures of a volatile chemical in two zones: the near-field and
the far-field. This is done because contaminant levels in the near-field are considered to provide a better
representation of a worker's personal breathing zone than those in the far-field. This model presents
estimates for both the near and far-field scenarios, representing workers directly involved in the specific
process (near-field) and other workers in the area (far-field).
Sources/Activities That Use This Model as a Default
None.
Other Sources/Activities
The EPA/OPPT Near-Field / Far-Field Inhalation Model may be an appropriate alternative to the
default inhalation model for the following sources/activities:
• Miscellaneous Sources/Activities Related to Liquid Processing
• Miscellaneous Sources/Activities Related to Solid Processing
Potential Routes of Exposure
Inhalation
Equations
Parameters
Description
Equation
Units |
Cm
Mass concentration of
chemical in air
User will toggle between Cnf_TWA and Cff_TWA
mg/m3
Cnf_TWA
Mass concentration of
((G x 3600000 x (kl x h + k2 x EXP(lambdal x h) / lambdal -
mg/m3
320
-------
ChemSTEER User Guide - Updated May 2015
chemical in near-field air
k3 x EXP(lambda2 x h) / Iambda2)) - (G x 3600000 x k2 /
lambdal - k3 / Iambda2)) / h |
Cff_TWA Mass concentration of
chemical in far-field air
((G x 3600000 x (h / QFF + k4 x EXP(lambdal x h) / lambdal i mg/m3
- k5 x EXP(lambda2 x h) / Iambda2)) - (G x 3600000 x k4 /
lambdal - k5 / Iambda2)) / h |
1
Inhalation potential dose Cm x b x h mg/day
rate
NW
Total number of workers
exposed
NWexp x NS
workers
LADD Lifetime average daily
dose
(1 x ED x EY) / (BW x ATc x 365 days / yr)
mg/kg-
day
ADD 1 Average daily dose
(1 x ED x EY) / (BW x AT x 365 days / yr)
mg/kg-
day
APDR I Acute potential dose rate
l/BW
mg/kg-
day
VNF
Volume of Near-Field
LNFxWNFx HNF
FSA
Free Surface Area
2x(LNFxHNF) + 2x (WNF x HNF) + (LNF x WNF)
m2
QNF
Near-Field Ventilation 0.5 x FSA x velocityNF
Rate J
m3/hr
QFF
Far-Field Ventilation Rate
VFFxAER
m3/hr
kl
Intermediate Parameter 1 1/((QNF/(QNF + QFF)) x QFF) I hr/m3
kl I I
k2 Intermediate Parameter 1 (QNF x QFF + Iambda2 x VNF x (QNF + QFF)) / (QNF x QFF x 1 hr/m3
1 k2 1 VNF x (lambdal - Iambda2)) |
k3 Intermediate Parameter I (QNF x QFF + lambdal x VNF x (QNF + QFF)) / (QNF x QFF x
1 k3 J VNF x (lambdal - Iambda2))
hr/m3
k4 Intermediate Parameter
1 k4
((lambdal x VNF + QNF) / QNF) x k2
hr/m3
k5
Intermediate Parameter ((Iambda2 x VNF + QNF) / QNF) x k3
k5 [
hr/m3
lambdal
Intermediate Parameter
lambdal
0.5 x (-Y + ((YA2) - Z)A0.5)
1/hr
Iambda2 Intermediate Parameter
I Iambda2
0.5 x (-Y - ((YA2) - Z)A0.5)
1/hr
Y
Intermediate Parameter
Y
(QNF x VFF + VNF x (QNF + QFF)) / (VNF x VFF)
1/hr
Z Intermediate Parameter
1 Z
4 x QNF x QFF / VNF / VFF
1/hr
Model Input Parameters and Default Values
The EPA/OPPT Near-Field/Far-Field Inhalation Exposure Model default values for each of the
input parameters are summarized in Table B-lla.
321
-------
ChemSTEER User Guide - Updated May 2015
Table B-lla. Input Parameters and Default Values for the EPA/OPPT Near-Field/Far-Field Inhalation
Exposure Model
Parameter
Description
Default Value(s)
Units
Basis
b
Volumetric inhalation rate (0 < b < 7.9)
1.25
m3/hr
EPA, 1991
h
Exposure duration (0 < h < 24)
h (from the associated vapor
generation model or a User-
defined G in the Release
tab)
hrs/day
N/A
NWexp
Number of workers exposed while
performing the activity
1
workers/site
N/A
NS
Number of sites
NS
(from Mass Balance
Parameters subtab of
Operation Parameters tab)
site(s)
N/A
ED
Days exposed per year
(0 < ED (integer) < 365)
OD
(from Mass Balance
Parameters subtab of
Operation Parameters tab;
default: 250)
days/site-yr
N/A
EY
Years of occupational exposure (0 < EY)
40
years
EPA, 1993
BW
Body weight (0 < BW)
70
kg
EPA, 1993
ATc
Averaging time over a lifetime (chronic)
(0 < ATc)
70
years
EPA, 1993
AT
Averaging time (EY < AT < ATc)
EY
years
EPA, 1993
VFF
Volume of Far-Field
User-defined
m3
N/A
AER
Air Exchange Rate
User-defined
1/hr
N/A
velocityNF
Near-Field indoor wind speed
360
m/hr
EPA, 2014
LNF
Length of Near-Field
3.05
m
EPA, 2014
WNF
Width of Near-Field
3.05
m
EPA, 2014
HNF
Height of Near-Field
1.83
m
EPA, 2014
G
Vapor generation rate
G (from the associated
vapor generation model or a
User-defined G in the
Release tab)
g/s
N/A
You may elect to change any parameter from Table B-lla. Clicking the Type column for each
changeable parameter other than VFF and AER contains only two options: ChemSTEER defaults from
Table B-lla and User-defined. The non-default options for VFF and AER are presented in tables B-llb
and B-llc below. Be sure to read the General Information on Using Models topic for more information
about changing model parameters.
Default Parameter Value Switch Settings and Results Characterization
322
-------
ChemSTEER User Guide - Updated May 2015
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Near Field (Cm = Cnf_TWA as default)
Default Characterization of Output 2 Results: Far Field (Cm = Cff_TWA as default)
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Release Model
Information screen:
"EPA/OPPT Near-Field/Far-Field Inhalation Exposure Model"
Table B-llbfor VFF for the EPA/OPPT Near-Field/Far-Field Inhalation Exposure Model
Scenario
VFF (m3)
Low End
300
High End
2,000
Source: EPA, 2014
Table B-llc for Air Exchange Rate (AER) for the EPA/OPPT Near-Field/Far-Field Inhalation Exposure
Model
Scenario
AER (1/hr) |
Low End
2
High End
15
Source: EPA, 2014
Key Rationale for Model
Keil et al. (2009) developed the Near-Field/Far-Field model to estimate exposure concentrations
to volatile chemicals in specific breathing zones. The Near-Field/Far-Field model has been extensively
peer-reviewed, is extensively used, and results of the model have been compared with measured data.
The comparison indicated that model and measured values agreed to within a factor of about three
(Jayjock et al., 2011). This model was applied in the TSCA Work Plan Risk Assessment for
Trichloroethylene (EPA, 2014), to estimate worker exposures at vapor degreasing facilities. Default and
non-default values for AER, velocity NF, LNF, WNF, HNF were taken from EPA, 2014.
References
US EPA/OPPT. TSCA Work Plan Chemical Risk Assessment. Trichloroethylene: Degreasing, Spot
Cleaning and Arts & Craft Uses. CASRN: 79-01-6. EPA Document # 740-R1-4002. June 2014.
http://www.epa.gov/oppt/existingchemicals/pubs/TCE_OPPTWorkplanChemRA_FINAL_062414.
pdf
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
323
-------
ChemSTEER User Guide - Updated May 2015
Jayjock, M. A., T. Armstrong, and M. Taylor. 2011. The Daubert Standard as Applied to Exposure
Assessment Modeling Using the Two-Zone (NF/FF) Model Estimation of Indoor Air Breathing
Zone Concentration as an Example. Journal of Occupational and Environmental Hygiene, 8(11),
D114-D122.
Keil, C. B., C. E. Simmons, and A. T. Renee. 2009. Mathematical Models for Estimating
Occupational Exposure to Chemicals (2nd ed.) American Industrial Hygiene Association (AIHA)
Model Description
This model estimates the amount of chemical inhaled by a worker during an activity. Estimation
of the concentration for inhalation exposure is based on a user input concentration.
Sources/Activities That Use This Model as a Default
The following sources/activities use the User-Defined Inhalation Model as the default for
calculating worker inhalation exposures:
• Miscellaneous Sources/Activities Related to Liquid Processing
• Aqueous Wash of Organic Mass
• Scrubber Releases
• Coating Using Hand Held Spray Can
This model is appropriate to use as an alternative inhalation model for all other ChemSTEER
sources/activities (except the Recirculating Water-Cooling Tower Additive Releases source/activity).
Potential Route / Form(s) of Exposure
Inhalation / Vapor, particulate, mist, aerosols, etc.
NOTE: The model will default to Chemical State = 'Mist' when the adjusted vapor pressure of the
substance being handled (e.g., AVPrm, AVPprod) (calculated on the Operation Parameters tab,
Shared Parameters/Factors subtab) is outside of the preferred range of adjusted vapor
pressures (i.e., is less than AVPlow). To read more about these settings, refer to the following
topics:
Vapor Model Activation
Operation Parameters Tab -> Shared Parameters/Factors Subtab
324
-------
ChemSTEER User Guide - Updated May 2015
Equations
Parameters
Description
Equation
Units
Cm
Mass concentration of chemical in air
Cv x MW / Vm x Ys
mg/m3
1
Inhalation potential dose rate
Cm x b x h
mg/day
NW
Total number of workers exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(1 x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(1 x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
l/BW
mg/kg-day
Model Input Parameters and Default Values
The User-Defined Inhalation Model default values for each of the input parameters are
summarized in Table B-12.
Table B-12. Input Parameters and Default Values for the User-Defined Inhalation Model
Parameter
Description
Default Value(s)
Units
Cv
Volumetric concentration of
chemical in air (0 < Cv)
User-defined Cv
ppm
MW
Molecular weight of the chemical (0
< MW)
MW (from Chemical tab)
g/mol
Vm
Molar volume (0 < Vm)
24.45 @ 25°C, 1 atm
L/mol
Cm
Mass concentration of chemical in
air (0 < Cm)
Calculated from model equation or User-
defined Cm
mg/m3
Ys
Weight fraction of chemical in
mixture (0 < Yx < l)1
1
dimensionless
b
Volumetric inhalation rate (0 < b <
7.9)
1.25
m3/hr
h
Exposure duration (0 < h < 24)
Defaults specified in Table B-12a
hrs/day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters subtab of
the Operation Parameters tab)
site(s)
ED
Days exposed per year (0 < ED
(integer) < 365)
Defaults specified in Table B-12b
days/site-yr
EY
Years of occupational exposure (0 <
EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime
(chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
1. Ys may be used to adjust the airborne concentration, as appropriate.
You may elect to change any parameter from Table B-12. If you enter a user-defined value for
Cm, the values of Cv, MW, and Vm are not used in the model. Clicking the Type column for each
325
-------
ChemSTEER User Guide - Updated May 2015
changeable parameter other than Cv, Cm, Ys, h, and ED contains only two options: ChemSTEER defaults
from Table B-12 and User-defined. You must enter a value for Cv or Cm in this exposure model. The
conditional default and non-default options for h and ED are presented in the tables below. Be sure to
read the ChemSTEER Estimation Methods and Models topic for more information about changing model
parameters.
The non-default options for Ys are Yrm, Yprod, Yi (for container-related sources/activities only),
and User-defined Ys. These non-default options are available by clicking in the Type column in the
View/Update Exposure Model Information screen in the Exposures tab.
NOTE: It is assumed that the same number of workers exposed by inhaling the chemical during
the activity will also be dermally exposed (if a dermal exposure is expected). If you update the
number of workers exposed (NWexp), the NWexp for the corresponding output in the dermal
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the dermal
model will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Output 1
Default Characterization of Output 2 Results: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"User-Defined Inhalation Model"
326
-------
ChemSTEER User Guide - Updated May 2015
Table B-12a. Conditional Default Values for h for the User-Defined Inhalation Model
Associated Release
Model
Source / Activity Type
Conditional h Default*
(hrs/site-day)
Yes
Any type
Lesser of 8 or OHa from an associated release
model**
(from Releases tab)
No
Container-Related
Lesser of 8 or OHa
(from Container Parameters subtab of the
Operation Parameters tab)
Sampling
1
Equipment Cleaning Losses of Liquids from
Multiple Vessels
4
Equipment Cleaning Losses of Liquids from
a Single, Large Vessel
1
Equipment Cleaning Losses of Liquids from
a Single, Small Vessel
0.5
Not Container-Related, Sampling, or
Equipment Cleaning
8
*See Table B-12c for the hierarchy of logic for extracting an h value from an associated release model.
327
-------
ChemSTEER User Guide - Updated May 2015
Table B-12b. Conditional Default Values for ED for the User-Defined Inhalation Model
Associated Release Model /
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default (days
of exposure/site-yr)
Non-default
Options for
ED**
Yes
/ Container-related
/ Continuous
Not applicable
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
OD (days/site-
yr)
ODa (days/site-
yr)
User-defined
ED
Yes
/ Container-related
/ Batch
Any
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
Nby (bt/site-yr)
OD (days/site-
yr)
ODa (days/site-
yr)
User-defined
ED
Yes
/ Not Container-related
/ Continuous
Not applicable
Lesser of 250 or Freq from
associated release model*
(from Release tab)
OD (days/site-
yr)
User-defined
ED
Yes
/ Not Container-related
/ Batch
Any
Lesser of 250 or Freq from
associated release model*
(from Releases tab)
Nby (bt/site-yr)
OD (days/site-
yr)
User-defined
ED
No associated release model
/ Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operations
Parameters tab)
OD (das/site-yr)
User-defined
ED
No associated release model
/Container-Related
/Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operations
Parameters tab)
Nby (bt/site-yr)
OD (days/st-yr)
User-defined
ED
No associated release model
/ Not Container-Related
/Continuous
Not applicable
Lesser of 250 or OD
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
User-defined
ED
No associated release model
/ Not Container-Related
/ Batch
Number of batches per day
(Nbd)< 1
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
Lesser of 250 or Nby
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
OD (days/site-
yr)
User-defined
ED
Number of batches per day
(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
Lesser of 250 or OD
(from Mass Balance
Parameters subtab of the
Operation Parameters tab)
Nby (bt/site-yr)
User-defined
ED
*See Table B-12c for the hierarchy of logic for extracting an ED value from an associated release model.
328
-------
ChemSTEER User Guide - Updated May 2015
**Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab.
Table B-12c. Hierarchy for Extracting Parameter Defaults from Associated Release Models* for the
User-Defined Inhalation Model
1. Use current value of parameter from the last associated vapor generation model* for the source/activity
(from the Releases tab).
2. Use current value of parameter from the last associated release model* for the source/activity (from the
Releases tab) - only if there is not associated vapor generation model.
3. If no associated release model* for the source/activity, then use conditional default as described for "No
associated release model" in Tables B-12a and B-12b above.
*The associated release model is the LAST vapor generation or release model that contains a parameter value
required for the EPA/OPPT Mass Balance Inhalation Model that is listed in the Release Model(s) for Selected
Activity box in the Releases tab (i.e., it is the last vapor generation or release model that was added by either
ChemSTEER or the user) for the selected Source/Activity.
When extracting parameter values from the Releases tab, the EPA/OPPT User-Defined Inhalation
Model Input Parameters for Output 1 are obtained from the associated release model Input Parameters
for Output 1; and the EPA/OPPT User-Defined Inhalation Model Input Parameters for Output 2 are
obtained from the associated release model Input Parameters for Output 2.
Key Rationale for Model
NA
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-1, 4-5)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
Models for Calculating Dermal Exposures
E""
Model Description
This model estimates dermal exposure to the chemical for 1-hand contact with liquid containing
the chemical.
Sources/Activities That Use This Model as a Default
The EPA/OPPT 1-Hand Dermal Contact with Liquid Model is the default for calculating worker
dermal exposures to a liquid chemical while performing Sampling Liquids sources/activities.
329
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT 1-Hand Dermal Contact with Liquid Model - Other Sources/Activities
The EPA/OPPT 1-Hand Dermal Contact with Liquid Model may be an appropriate alternative to
the default dermal model for the following sources/activities:
• All sources/activities for Cleaning Liquid Residuals from Transport Containers/Vessels
• All sources/activities for Loading Liquids into Transport Containers/Vessels
• All sources/activities for Unloading Liquids from Transport Containers/Vessels
• All sources/activities for Equipment Cleaning Losses of Liquids
• Miscellaneous Sources/Activities Related to Liquid Processing
• Filter Media Changeout
Potential Route / Form(s) of Exposure
Dermal contact / Liquid
Equations
Parameters
Description
Equation
Units
Dexp
Dermal potential dose rate
S x Qu x Yderm x FT
mg/day
NW
Total number of workers
exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(Dexp x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(Dexp x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
Dexp/BW
mg/kg-day
Model Input Parameters and Default Values
The EPA/OPPT 1-Hand Dermal Contact with Liquids Model default values for each of the input
parameters are summarized in Table B-12.
330
-------
ChemSTEER User Guide - Updated May 2015
Table B-12. Input Parameters and Default Values for the EPA/OPPT 1-Hand Dermal Contact with
Liquids Model
Parameter
Description
Default Value(s)
Units
S
Surface area of contact (one hand)
(constant)
535 (mean)
cm2
Qu
Quantity remaining on skin
(constant)
Output 1:
Default: 0.7 (low)
Non-default option: 2.1 (high)
mg/cm2-event
Output 2:
Default: 2.1 (high)
Non-default Option: 0.7 (low)
Yderm
Weight fraction of chemical in
liquid (0< Yderm < 1)
Defaults specified in Table B-12a
dimensionless
FT
Frequency of events (0 < FT
(integer)
1
events/worker-day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
site(s)
ED
Days exposed per year (0 < ED
(integer) < 365)
Defaults specified in Table B-12b
days/site-yr
EY
Years of occupational exposure (0
< EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime
(chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-12 except S and Qu, which are constants.
Clicking the Type column for each changeable parameter other than S, Qu, Yderm and ED contains only
two options: ChemSTEER defaults from Table B-12 and User-defined. The conditional default and non-
default options for Yderm and ED are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
Note on FT: Only one contact per day (FT = 1) is assumed because Qu, with few exceptions, is
not expected to be significantly affected either by wiping excess from skin or by repeated
contact(s) with additional chemical (i.e., wiping excess from the skin does not remove a
significant fraction of the small layer of chemical adhering to the skin and additional contacts
with the chemical do not add a significant fraction to the layer). Exceptions to this assumption
may be considered for chemicals with high volatility and/ or with very high rates of absorption
into the skin.
If you enter a User-defined FT and the value is greater than 1, ChemSTEER will display a warning
message with the following text: "The value of FT should not exceed 1 unless the chemical assessed is
331
-------
ChemSTEER User Guide - Updated May 2015
highly volatile or has a high rate of absorption. See the Note on FT in the User Guide topic for any dermal
model for more information on this issue." After clicking "OK" you will be allowed to continue.
You may not change the defining model parameters, Qu and S, to be anything other than the
defaults shown above. If you wish to model dermal exposures using your own data, choose the
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
User-Defined Dermal Model.
NOTE: It is assumed that the same number of workers dermally exposed to the chemical during
the activity will also have an inhalation exposure (if an inhalation exposure is expected). If you
update the number of workers exposed (NWexp), the NWexp for the corresponding output in
the inhalation model, selected for the same activity, will be automatically updated with the
entered value. For example, if you update NWexp for Output 2 in this model, NWexp for Output
2 in the inhalation model will be updated to the same value. The same is true if you update
NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Settings for either Output 1 or Output 2 results are based on which Qu is selected for the
corresponding output:
• Results using the low remaining quantity (Qu) are characterized as Output 1 by default.
• Results using the high remaining quantity (Qu) are characterized as High End by default.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT 1-Hand Dermal Contact with Liquids Model"
332
-------
ChemSTEER User Guide - Updated May 2015
Table B-12a. Conditional Default Values for Yderm for the EPA/OPPT 1-Hand Dermal Contact with
Liquids Model
Source/Activity Type / Material
Named in Sou rce/Activity Label
Operation
Type
Conditional Yderm Default
Non-default
Options for
Yderm
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtab of the Operation Parameters
tab)
Yrm
Yprod
User-defined
Yderm
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
Not Container Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Not Container-Related
/ Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
*Non-default options for Yderm are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for Yderm are available for both
Output 1 and Output 2.
333
-------
ChemSTEER User Guide - Updated May 2015
Table B-12b. Conditional Default Values for ED for the EPA/OPPT 1-Hand Dermal Contact with Liquids
Model
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default (days
of exposure/site-yr)
Non-default Options
for ED
Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-yr)
User-defined ED
Container-Related
/ Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-yr)
User-defined ED
Not Container Related
/ Continuous
Not applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-Related
/ Batch
Number of batches per
day(Nbd)< 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per
day(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for ED are available for both Output 1
and Output 2.
Key Rationale for Model
Dermal exposures to a chemical are estimated using standard assumptions documented in the
references, and assume no use of controls or gloves to reduce exposures. For a given worker activity,
this method assumes a specific surface area contacted by chemical and a specific surface density of that
chemical to estimate a PDR using the model equations.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-26)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure, September 2013.
334
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT2-Hand Dermal Contact with Liquid Model
Model Description
This model estimates dermal exposure to the chemical for 2-hand contact with liquid containing
the chemical.
Sources/Activities That Use This Model as a Default
The EPA/OPPT 2-Hand Dermal Contact with Liquid Model is the default for calculating worker
dermal exposures to a liquid chemical while performing the following sources/activities:
• All sources/activities for Cleaning Liquid Residuals from Transport Containers/Vessels
• All sources/activities for Loading Liquids into Transport Containers/Vessels
• All sources/activities for Unloading Liquids from Transport Containers/Vessels
• Aqueous Wash of Organic Mass
• Liquid/Liquid Extraction Solvent Disposal
EPA/OPPT 2-Hand Dermal Contact with Liquid Model - Other Sources/Activities
The EPA/OPPT 2-Hand Dermal Contact with Liquid Model may be an appropriate alternative to
the default dermal model for the following sources/activities:
• All sources/activities for Equipment Cleaning Losses of Liquids
• All sources/activities for Sampling Liquids
• Miscellaneous Sources/Activities Related to Liquid Processing
• Filter Media Changeout
• Roll Coating
Potential Route / Form(s) of Exposure
Dermal contact / Liquid
Equations
Parameters
Description
Equation
Units
Dexp
Dermal potential dose rate
S x Qu x Yderm x FT
mg/day
NW
Total number of workers
exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(Dexp x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(Dexp x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
Dexp/BW
mg/kg-day
Model Input Parameters and Default Values
335
-------
ChemSTEER User Guide - Updated May 2015
The EPA/OPPT 2-Hand Dermal Contact with Liquids Model default values for each of the input
parameters are summarized in Table B-13.
Table B-13. Input Parameters and Default Values for the EPA/OPPT 2-Hand Dermal Contact with
Liquids Model
Parameter
Description
Default Value(s)
Units
S
Surface area of contact (two
hands) (constant)
1,070 (mean)
cm2
Qu
Quantity remaining on skin
(constant)
Output 1:
Default: 0.7 (low)
Non-default option: 2.1 (high)
mg/cm2-event
Output 2:
Default: 2.1 (high)
Non-default Option: 0.7 (low)
Yderm
Weight fraction of chemical in
liquid (0< Yderm < 1)
Defaults specified in Table B-9a
dimensionless
FT
Frequency of events (0 < FT
(integer)
1
events/worker-day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
site(s)
ED
Days exposed per year (0 < ED
(integer) < 365)
Defaults specified in Table B-9b
days/site-yr
EY
Years of occupational exposure (0
< EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime
(chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-13 except S and Qu, which are constants.
Clicking the Type column for each changeable parameter other than S, Qu, Yderm and ED contains only
two options: ChemSTEER defaults from Table B-13 and User-defined. The conditional default and non-
default options for Yderm and ED are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
NOTE on FT: Only one contact per day (FT = 1) is assumed because Qu, with few exceptions, is
not expected to be significantly affected either by wiping excess from skin or by repeated
contact(s) with additional chemical (i.e., wiping excess from the skin does not remove a
significant fraction of the small layer of chemical adhering to the skin and additional contacts
with the chemical do not add a significant fraction to the layer). Exceptions to this assumption
may be considered for chemicals with high volatility and/ or with very high rates of absorption
into the skin.
336
-------
ChemSTEER User Guide - Updated May 2015
If you enter a User-defined FT and the value is greater than 1, ChemSTEER will display a warning
message with the following text: "The value of FT should not exceed 1 unless the chemical assessed is
highly volatile or has a high rate of absorption. See the Note on FT in the User Guide topic for any
dermal model for more information on this issue." After clicking "OK" you will be allowed to continue.
You may not change the defining model parameters, Qu and S, to be anything other than the
defaults shown above. If you wish to model dermal exposures using your own data, choose the
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
User-Defined Dermal Model.
NOTE: It is assumed that the same number of workers dermally exposed to the chemical during
the activity will also have an inhalation exposure (if an inhalation exposure is expected). If you update
the number of workers exposed (NWexp), the NWexp for the corresponding output in the inhalation
model, selected for the same activity, will be automatically updated with the entered value. For
example, if you update NWexp for Output 2 in this model, NWexp for Output 2 in the inhalation model
will be updated to the same value. The same is true if you update NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Settings for either Output 1 or Output 2 results are based on which Qu is selected for the
corresponding output:
• Results using the low remaining quantity (Qu) are characterized as Output 1 by default.
• Results using the high remaining quantity (Qu) are characterized as High End by default.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT 2-Hand Dermal Contact with Liquids Model"
337
-------
ChemSTEER User Guide - Updated May 2015
Table B-13a. Conditional Default Values for Yderm for the EPA/OPPT 2-Hand Dermal Contact with
Liquids Model
Source/Activity Type / Material
Named in Sou rce/Activity Label
Operation
Type
Conditional Yderm Default
Non-default
Options for
Yderm
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtab of the Operation Parameters
tab)
Yrm
Yprod
User-defined
Yderm
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
Not Container Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Not Container-Related
/ Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
*Non-default options for Yderm are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for Yderm are available for both
Output 1 and Output 2.
338
-------
ChemSTEER User Guide - Updated May 2015
Table B-13b. Conditional Default Values for ED for the EPA/OPPT 2-Hand Dermal Contact with Liquids
Model
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default (days
of exposure/site-yr)
Non-default Options
for ED
Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-yr)
User-defined ED
Container-Related
/ Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-yr)
User-defined ED
Not Container Related
/ Continuous
Not applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-Related
/ Batch
Number of batches per
day(Nbd)< 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per
day(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for ED are available for both Output 1
and Output 2.
Key Rationale for Model
Dermal exposures to a chemical are estimated using standard assumptions documented in the
references, and assume no use of controls or gloves to reduce exposures. For a given worker activity,
this method assumes a specific surface area contacted by chemical and a specific surface density of that
chemical to estimate a PDR using the model equations.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-26)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure, September 2013.
339
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT2-Hand Dermal Immersion with Liquid Model
Model Description
This model estimates dermal exposure to the chemical for 2-hand immersion in liquid containing
the chemical.
Sources/Activities That Use This Model as a Default
The EPA/OPPT 2-Hand Dermal Immersion in Liquids Model is the default for calculating worker
dermal exposures to a liquid chemical while performing the following sources/activities:
• All sources/activities for Automobile Spray Coating
• Miscellaneous Sources/Activities Related to Liquid Processing
EPA/OPPT 2-Hand Dermal Immersion in Liquids Model - Other Sources/Activities
The EPA/OPPT 2-Hand Dermal Immersion in Liquids Model may be an appropriate alternative to
the default dermal model for the following sources/activities:
• All sources/activities for Cleaning Liquid Residuals from Transport Containers/Vessels
• All sources/activities for Unloading Liquids from Transport Containers/Vessels
• All sources/activities for Equipment Cleaning Losses of Liquids
• All sources/activities for Sampling Liquids
• Filter Media Changeout
• Coating Using Hand Held Spray Gun
Potential Route / Form(s) of Exposure
Dermal contact / Liquid
Equations
Parameters
Description
Equation
Units
Dexp
Dermal potential dose rate
S x Qu x Yderm x FT
mg/day
NW
Total number of workers
exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(Dexp x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(Dexp x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
Dexp/BW
mg/kg-day
Model Input Parameters and Default Values
The EPA/OPPT 2-Hand Dermal Immersion in Liquids Model default values for each of the input
parameters are summarized in Table B-14.
340
-------
ChemSTEER User Guide - Updated May 2015
Table B-14. Input Parameters and Default Values for the EPA/OPPT 2-Hand Dermal Immersion in
Liquids Model
Parameter
Description
Default Value(s)
Units
S
Surface area of contact (two
hands) (constant)
1,070 (mean)
cm2
Qu
Quantity remaining on skin
(constant)
Output 1:
Default: 1.3 (low)
Non-default option: 10.3 (high)
mg/cm2-event
Output 2:
Default: 10.3 (high)
Non-default Option: 1.3 (low)
Yderm
Weight fraction of chemical in
liquid (0< Yderm < 1)
Defaults specified in Table B-14a
dimensionless
FT
Frequency of events (0 < FT
(integer)
1
events/worker-day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
site(s)
ED
Days exposed per year (0 < ED
(integer) < 365)
Defaults specified in Table B-14b
days/site-yr
EY
Years of occupational exposure (0
< EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime
(chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-14 except S and Qu, which are constants.
Clicking the Type column for each changeable parameter other than S, Qu, Yderm and ED contains only
two options: ChemSTEER defaults from Table B-14 and User-defined. The conditional default and non-
default options for Yderm and ED are presented in the tables below. Be sure to read the ChemSTEER
Estimation Methods and Models topic for more information about changing model parameters.
NOTE on FT: Only one contact per day (FT = 1) is assumed because Qu, with few exceptions, is
not expected to be significantly affected either by wiping excess from skin or by repeated
contact(s) with additional chemical (i.e., wiping excess from the skin does not remove a
significant fraction of the small layer of chemical adhering to the skin and additional contacts
with the chemical do not add a significant fraction to the layer). Exceptions to this assumption
may be considered for chemicals with high volatility and/ or with very high rates of absorption
into the skin.
If you enter a User-defined FT and the value is greater than 1, ChemSTEER will display a warning
message with the following text: "The value of FT should not exceed 1 unless the chemical assessed is
341
-------
ChemSTEER User Guide - Updated May 2015
highly volatile or has a high rate of absorption. See the Note on FT in the User Guide topic for any dermal
model for more information on this issue." After clicking "OK" you will be allowed to continue.
You may not change the defining model parameters, Qu and S, to be anything other than the
defaults shown above. If you wish to model dermal exposures using your own data, choose the
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
User-Defined Dermal Model.
NOTE: It is assumed that the same number of workers dermally exposed to the chemical during
the activity will also have an inhalation exposure (if an inhalation exposure is expected). If you
update the number of workers exposed (NWexp), the NWexp for the corresponding output in
the inhalation model, selected for the same activity, will be automatically updated with the
entered value. For example, if you update NWexp for Output 2 in this model, NWexp for Output
2 in the inhalation model will be updated to the same value. The same is true if you update
NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Settings for either Output 1 or Output 2 results are based on which Qu is selected for the
corresponding output:
• Results using the low remaining quantity (Qu) are characterized as Output 1 by default.
• Results using the high remaining quantity (Qu) are characterized as High End by default.
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT 2-Hand Dermal Immersion in Liquids Model."
342
-------
ChemSTEER User Guide - Updated May 2015
Table B-14a. Conditional Default Values for Yderm for the EPA/OPPT 2-Hand Dermal Immersion in
Liquids Model
Source/Activity Type / Material
Named in Sou rce/Activity Label
Operation
Type
Conditional Yderm Default
Non-default
Options for
Yderm
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtab of the Operation Parameters
tab)
Yrm
Yprod
User-defined
Yderm
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
Not Container Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Not Container-Related
/ Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
*Non-default options for Yderm are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for Yderm are available for both
Output 1 and Output 2.
343
-------
ChemSTEER User Guide - Updated May 2015
Table B-14b. Conditional Default Values for ED for the EPA/OPPT 2-Hand Dermal Immersion in Liquids
Model
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default (days
of exposure/site-yr)
Non-default Options
for ED
Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-yr)
User-defined ED
Container-Related
/ Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-yr)
User-defined ED
Not Container Related
/ Continuous
Not applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-Related
/ Batch
Number of batches per
day(Nbd)< 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per
day(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for ED are available for both Output 1
and Output 2.
Key Rationale for Model
Dermal exposures to a chemical are estimated using standard assumptions documented in the
references, and assume no use of controls or gloves to reduce exposures. For a given worker activity,
this method assumes a specific surface area contacted by chemical and a specific surface density of that
chemical to estimate a PDR using the model equations.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-26)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
344
-------
ChemSTEER User Guide - Updated May 2015
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure, September 2013.
EPA/OPPTDirect 2-Hand Dermal Contact with Solids Model
Model Description
This model estimates dermal exposure to the chemical for direct 2-hand contact with solids
containing the chemical.
Sources/Activities That Use This Model as a Default
The EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model is the default for calculating
worker dermal exposures to a solid chemical while performing the following sources/activities:
• All sources/activities for Cleaning Solid Residuals from Transport Containers/Vessels
• All sources/activities for Loading Solids into Transport Containers/Vessels
• All sources/activities for Unloading Solids from Transport Containers/Vessels
• All sources/activities for Sampling Solids
• Equipment Cleaning Losses of Solids
• Miscellaneous Sources/Activities Related to Solid Processing
• Filter Media Changeout
• Grinding and Sanding
This model is not used as an alternative dermal exposure model for any other sources/activities.
Potential Route / Form(s) of Exposure
Dermal contact / Solid
Equations
Parameters
Description
Equation
Units
Dexp
Dermal potential dose rate
S x Qu x Yderm x FT
mg/day
NW
Total number of workers
exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(Dexp x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(Dexp x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
Dexp/BW
mg/kg-day
Model Input Parameters and Default Values
The EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model default values for each of the
input parameters are summarized in Table B-15.
345
-------
ChemSTEER User Guide - Updated May 2015
Table B-15. Input Parameters and Default Values for the EPA/OPPT Direct 2-Hand Dermal Contact with
Solids Model
Parameter
Description
Default Value(s)
Units
S x Qu
Total amount of solids on skin
3,100 (high)
mg/event
Yderm
Weight fraction of chemical in
liquid (0< Yderm < 1)
Defaults specified in Table B-15a
dimensionless
FT
Frequency of events (0 < FT
(integer)
1
events/worker-day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
site(s)
ED
Days exposed per year (0 < ED
(integer) < 365)
Defaults specified in Table B-15b
days/site-yr
EY
Years of occupational exposure (0
< EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime
(chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-15 except (S x Qu), which are constants.
Clicking the Type column for each changeable parameter other than (S x Qu), Yderm and ED contains
only two options: ChemSTEER defaults from Table B-15 and User-defined. The conditional default and
non-default options for Yderm and ED are presented in the tables below. Be sure to read the
ChemSTEER Estimation Methods and Models topic for more information about changing model
parameters.
NOTE on FT: Only one contact per day (FT = 1) is assumed because Qu, with few exceptions, is
not expected to be significantly affected either by wiping excess from skin or by repeated
contact(s) with additional chemical (i.e., wiping excess from the skin does not remove a
significant fraction of the small layer of chemical adhering to the skin and additional contacts
with the chemical do not add a significant fraction to the layer). Exceptions to this assumption
may be considered for chemicals with high volatility and/ or with very high rates of absorption
into the skin.
If you enter a User-defined FT and the value is greater than 1, ChemSTEER will display a warning
message with the following text: "The value of FT should not exceed 1 unless the chemical assessed is
highly volatile or has a high rate of absorption. See the Note on FT in the User Guide topic for any dermal
model for more information on this issue." After clicking "OK" you will be allowed to continue.
You may not change the defining model parameter, (Qu x S), to be anything other than the
default shown above. If you wish to model dermal exposures using your own data, choose the
346
-------
ChemSTEER User Guide - Updated May 2015
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
User-Defined Dermal Model.
NOTE: It is assumed that the same number of workers dermally exposed to the chemical during
the activity will also have an inhalation exposure (if an inhalation exposure is expected). If you
update the number of workers exposed (NWexp), the NWexp for the corresponding output in
the inhalation model, selected for the same activity, will be automatically updated with the
entered value. For example, if you update NWexp for Output 2 in this model, NWexp for Output
2 in the inhalation model will be updated to the same value. The same is true if you update
NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: High End
Default Characterization of Output 2 Results: High End
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model"
347
-------
ChemSTEER User Guide - Updated May 2015
Table B-15a. Conditional Default Values for Yderm for the EPA/OPPT Direct 2-Hand Dermal Contact
with Solids Model
Source/Activity Type / Material
Named in Sou rce/Activity Label
Operation
Type
Conditional Yderm Default
Non-default
Options for
Yderm
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtab of the Operation Parameters
tab)
Yrm
Yprod
User-defined
Yderm
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
Not Container Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Not Container-Related
/ Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
*Non-default options for Yderm are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for Yderm are available for both
Output 1 and Output 2.
348
-------
ChemSTEER User Guide - Updated May 2015
Table B-15b. Conditional Default Values for ED for the EPA/OPPT Direct 2-Hand Dermal Contact with
Solids Model
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default (days
of exposure/site-yr)
Non-default Options
for ED
Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-yr)
User-defined ED
Container-Related
/ Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-yr)
User-defined ED
Not Container Related
/ Continuous
Not applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-Related
/ Batch
Number of batches per
day(Nbd)< 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per
day(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for ED are available for both Output 1
and Output 2.
Key Rationale for Model
Dermal exposures to a chemical are estimated using standard assumptions documented in the
references, and assume no use of controls or gloves to reduce exposures. For a given worker activity,
this method assumes a specific surface area contacted by chemical and a specific surface density of that
chemical to estimate a PDR using the model equations.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-26)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
US EPA Memo entitled Revision to CEB's Method for Screening-Level Assessments of Dermal
Exposure, June 2000.
349
-------
ChemSTEER User Guide - Updated May 2015
EPA/OPPT2-Hand Dermal Contact with Container Surfaces Model
Model Description
This model estimates dermal exposure to the chemical for 2-hand contact with surfaces on
which solids containing the chemical are present.
Sources/Activities That Use This Model as a Default
There are no sources/activities in ChemSTEER that use this model as a default for calculating
worker dermal exposures to a chemical.
EPA/OPPT 2-Hand Dermal Contact with Container Surfaces (Solids) Model - Sources/Activities
The EPA/OPPT 2-Hand Dermal Contact with Container Surfaces (solids) Model may be an
appropriate means to calculate worker dermal exposures to a solid chemical while performing the
following sources/activities:
• All sources/activities for Cleaning Solid Residuals from Transport Containers/Vessels
• All sources/activities for Unloading Solids from Transport Containers/Vessels
• All sources/activities for Sampling Solids
• Equipment Cleaning Losses of Solids
• Miscellaneous Sources/Activities Related to Solid Processing
• Filter Media Changeout
• Grinding and Sanding
Potential Route / Form(s) of Exposure
Dermal contact / Solid
Equations
Parameters
Description
Equation
Units
Dexp
Dermal potential dose rate
S x Qu x Yderm x FT
mg/day
NW
Total number of workers
exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(Dexp x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(Dexp x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
Dexp/BW
mg/kg-day
Model Input Parameters and Default Values
The EPA/OPPT 2-Hand Dermal Contact with Container Surfaces (Solids) Model default values for
each of the input parameters are summarized in Table B-16.
350
-------
ChemSTEER User Guide - Updated May 2015
Table B-16. Input Parameters and Default Values for the EPA/OPPT 2-Hand Dermal Contact with
Container Surfaces (Solids) Model
Parameter
Description
Default Value(s)
Units
S x Qu
Total amount of solids on skin
1,100 (high)
mg/event
Yderm
Weight fraction of chemical in
liquid (0< Yderm < 1)
Defaults specified in Table B-16a
dimensionless
FT
Frequency of events (0 < FT
(integer)
1
events/worker-day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
site(s)
ED
Days exposed per year (0 < ED
(integer) < 365)
Defaults specified in Table B-16b
days/site-yr
EY
Years of occupational exposure (0
< EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime
(chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-16 except (S x Qu), which is a constant.
Clicking the Type column for each changeable parameter other than (S x Qu), Yderm and ED contains
only two options: ChemSTEER defaults from Table B-16 and User-defined. The conditional default and
non-default options for Yderm and ED are presented in the tables below. Be sure to read the
ChemSTEER Estimation Methods and Models topic for more information about changing model
parameters.
NOTE on FT: Only one contact per day (FT = 1) is assumed because Qu, with few exceptions, is
not expected to be significantly affected either by wiping excess from skin or by repeated
contact(s) with additional chemical (i.e., wiping excess from the skin does not remove a
significant fraction of the small layer of chemical adhering to the skin and additional contacts
with the chemical do not add a significant fraction to the layer). Exceptions to this assumption
may be considered for chemicals with high volatility and/ or with very high rates of absorption
into the skin.
If you enter a User-defined FT and the value is greater than 1, ChemSTEER will display a warning
message with the following text: "The value of FT should not exceed 1 unless the chemical assessed is
highly volatile or has a high rate of absorption. See the Note on FT in the User Guide topic for any dermal
model for more information on this issue." After clicking "OK" you will be allowed to continue.
You may not change the defining model parameter, (Qu x S), to be anything other than the
default shown above. If you wish to model dermal exposures using your own data, choose the
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
351
-------
ChemSTEER User Guide - Updated May 2015
User-Defined Dermal Model.
NOTE: It is assumed that the same number of workers dermally exposed to the chemical during
the activity will also have an inhalation exposure (if an inhalation exposure is expected). If you
update the number of workers exposed (NWexp), the NWexp for the corresponding output in
the inhalation model, selected for the same activity, will be automatically updated with the
entered value. For example, if you update NWexp for Output 2 in this model, NWexp for Output
2 in the inhalation model will be updated to the same value. The same is true if you update
NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Disabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: High End
Default Characterization of Output 2 Results: High End
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"EPA/OPPT 2-Hand Dermal Contact with Container Surfaces (Solids) Model"
352
-------
ChemSTEER User Guide - Updated May 2015
Table B-16a. Conditional Default Values for Yderm for the EPA/OPPT 2-Hand Dermal Contact with
Container Surfaces (Solids) Model
Source/Activity Type / Material
Named in Sou rce/Activity Label
Operation
Type
Conditional Yderm Default
Non-default
Options for
Yderm
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtab of the Operation Parameters
tab)
Yrm
Yprod
User-defined
Yderm
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
Not Container Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Not Container-Related
/ Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
*Non-default options for Yderm are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for Yderm are available for both
Output 1 and Output 2.
353
-------
ChemSTEER User Guide - Updated May 2015
Table B-16b. Conditional Default Values for ED for the EPA/OPPT 2-Hand Dermal Contact with
Container Surfaces (Solids) Model
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default (days
of exposure/site-yr)
Non-default Options
for ED
Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-yr)
User-defined ED
Container-Related
/ Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-yr)
User-defined ED
Not Container Related
/ Continuous
Not applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-Related
/ Batch
Number of batches per
day(Nbd)< 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per
day(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for ED are available for both Output 1
and Output 2.
Key Rationale for Model
Dermal exposures to a chemical are estimated using standard assumptions documented in the
references, and assume no use of controls or gloves to reduce exposures. For a given worker activity,
this method assumes a specific surface area contacted by chemical and a specific surface density of that
chemical to estimate a PDR using the model equations.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-26)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure, September 2013.
354
-------
ChemSTEER User Guide - Updated May 2015
User-Defined Dermal Model
Model Description
This model estimates the amount of chemical potentially contacted to a worker's skin during an
activity. Estimation of the exposure amount is based on user-input values of skin surface area contacted
and amount per area contacted.
Sources/Activities That Use This Model as a Default
There are no sources/activities in ChemSTEER that use this model as a default for calculating
worker dermal exposures to a chemical.
This model is appropriate to use as an alternative dermal model for all other ChemSTEER
sources/activities (except the Recirculating Water-Cooling Tower Additive Releases source/activity).
Potential Route / Form(s) of Exposure
Dermal contact / Liquid or solid
Equations
Parameters
Description
Equation
Units
Dexp
Dermal potential dose rate
S x Qu x Yderm x FT
mg/day
NW
Total number of workers
exposed
NWexp x NS
workers
LADD
Lifetime average daily dose
(Dexp x ED x EY)/(BW x ATc x 365 days/yr)
mg/kg-day
ADD
Average daily dose
(Dexp x ED x EY)/(BW x AT x 365 days/yr)
mg/kg-day
APDR
Acute potential dose rate
Dexp/BW
mg/kg-day
Model Input Parameters and Default Values
The User-Defined Dermal Model default values for each of the input parameters are
summarized in Table B-17.
355
-------
ChemSTEER User Guide - Updated May 2015
Table B-17. Input Parameters and Default Values for the User-Defined Dermal Model
Parameter
Description
Default Value(s)
Units
S
Surface area of contact (one
hands) (constant)
Output 1:
Default: 535 (low, one hand)
Non-default Options: 1,070 (high,
two hands) and User-defined S
cm2
Output 2:
Default: 1,070 (high, two hands)
Non-default Options: 535 (low,
one hand) and User-defined S
Qu
Quantity remaining on skin
(constant)
Output 1:
Default: 0.7 (low)
Non-default option: 2.1 (high) and
User-defined Qu
mg/cm2-event
Output 2:
Default: 2.1 (high)
Non-default Option: 0.7 (low) and
User-defined Qu
Yderm
Weight fraction of chemical in
liquid (0< Yderm < 1)
Defaults specified in Table B-17a
dimensionless
FT
Frequency of events (0 < FT
(integer)
1
events/worker-day
NWexp
Number of workers exposed while
performing the activity
1
workers/site
NS
Number or sites
NS
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
site(s)
ED
Days exposed per year (0 < ED
(integer) < 365)
Defaults specified in Table B-17b
days/site-yr
EY
Years of occupational exposure (0
< EY)
40
years
BW
Body weight (0 < ATc)
70
kg
ATc
Averaging time over a lifetime
(chronic) (0 < ATc)
70
years
AT
Averaging time (EY < AT < ATc)
EY
years
You may elect to change any parameter from Table B-17. Clicking the Type column for each
changeable parameter other than Yderm and ED contains only two options: ChemSTEER defaults from
Table B-17 and User-defined. You may elect to enter values for S and/or Qu in this exposure model.
Alternatively, you may select one of the default values shown in Table B-17. The conditional default and
non-default options for Yderm and ED are presented in the tables below. Be sure to read the
ChemSTEER Estimation Methods and Models topic for more information about changing model
parameters.
NOTE on FT: Only one contact per day (FT = 1) is assumed because Qu, with few exceptions, is
not expected to be significantly affected either by wiping excess from skin or by repeated
356
-------
ChemSTEER User Guide - Updated May 2015
contact(s) with additional chemical (i.e., wiping excess from the skin does not remove a
significant fraction of the small layer of chemical adhering to the skin and additional contacts
with the chemical do not add a significant fraction to the layer). Exceptions to this assumption
may be considered for chemicals with high volatility and/ or with very high rates of absorption
into the skin.
If you enter a User-defined FT and the value is greater than 1, ChemSTEER will display a warning
message with the following text:
"The value of FT should not exceed 1 unless the chemical assessed is highly volatile or
has a high rate of absorption. See the Note on FT in the User Guide topic for any dermal
model for more information on this issue."
After clicking "OK" you will be allowed to continue.
NOTE: It is assumed that the same number of workers dermally exposed to the chemical during
the activity will also have an inhalation exposure (if an inhalation exposure is expected). If you
update the number of workers exposed (NWexp), the NWexp for the corresponding output in
the inhalation model, selected for the same activity, will be automatically updated with the
entered value. For example, if you update NWexp for Output 2 in this model, NWexp for Output
2 in the inhalation model will be updated to the same value. The same is true if you update
NWexp for Output 1.
Default Parameter Value Switch Settings and Results Characterization
Enable Model Parameters for Output 1: Enabled
Enable Model Parameters for Output 2: Enabled
Default Characterization of Output 1 Results: Output 1
Default Characterization of Output 2 Results: Output 2
You may select an alternative characterization for either of the outputs at any time.
Default Model Basis
The following default text is displayed in the Basis box on the View/Update Exposure Model
Information screen:
"User-Defined Dermal Model"
357
-------
ChemSTEER User Guide - Updated May 2015
Table B-17a. Conditional Default Values for Yderm for the User-Defined Dermal Model
Source/Activity Type / Material
Named in Sou rce/Activity Label
Operation
Type
Conditional Yderm Default
Non-default
Options for
Yderm
Container-Related
/Any
Any
Yi
(from the Container Parameters
subtab of the Operation Parameters
tab)
Yrm
Yprod
User-defined
Yderm
Not Container-Related
/ Raw Material
Any
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
Not Container Related
/ Product
Any
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Not Container-Related
/ Neither Raw Material nor Product
Manufacturing
Yprod
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yrm
User-defined
Yderm
Processing
Use
Yrm
(from Mass Balance Parameters
subtab of the Operation Parameters
tab)
Yprod
User-defined
Yderm
*Non-default options for Yderm are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for Yderm are available for both
Output 1 and Output 2.
358
-------
ChemSTEER User Guide - Updated May 2015
Table B-17b. Conditional Default Values for ED for the User-Defined Dermal Model
Source/Activity Type /
Operation Mode
Batch Condition
Conditional ED Default (days
of exposure/site-yr)
Non-default Options
for ED
Container-Related
/ Continuous
Not applicable
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
OD (days/site-yr)
User-defined ED
Container-Related
/ Batch
Any
Lesser of 250 or ODa
(from Container Parameters
subtab of the Operation
Parameters tab)
Nby (bt/site-yr)
OD (days/site-yr)
User-defined ED
Not Container Related
/ Continuous
Not applicable
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
User-defined ED
Not Container-Related
/ Batch
Number of batches per
day(Nbd)< 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or Nby
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
OD
User-defined ED
Number of batches per
day(Nbd)> 1
(from Mass Balance
Parameters subtab of the
Operation Parameters
tab)
Lesser of 250 or OD
(from Mass Balance Parameters
subtab of the Operation
Parameters tab)
Nby
User-defined ED
*Non-default options for ED are available by clicking in the Type column in the View/Update Exposure Model
Information screen in the Exposures tab. All default and non-default options for ED are available for both Output 1
and Output 2.
Key Rationale for Model
For a given worker activity, this method assumes a user-defined surface area contacted by
chemical and a user-defined surface density of that chemical to estimate a Dexp using the model
equations.
References
US EPA/OPPT/CEB. Chemical Engineering Branch Manual for the Preparation of Engineering
Assessments, Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection
Agency, 1991. (Equations 4-26)
US EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical
Engineering Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure, September 2013.
359
-------
ChemSTEER User Guide - Updated May 2015
Models for Calculating Exposures to Liquids
The following models may be selected for sources/activities that result in inhalation exposure to
evaporation:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following models may be selected for sources/activities that result in inhalation exposure
during container filling:
• EPA/OPPT Mass Balance Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• User-Defined Inhalation Model
The following models may be selected for sources/activities that result in inhalation exposure to
mists:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA Total PNOR PEL-Limiting Model
• OSHA Respirable PNOR PEL-Limiting Model
• EPA/OPPT Automobile OEM Spray Coating Inhalation Exposure Model
• EPA/OPPT Automobile Refinish Spray Coating Inhalation Exposure Model
• EPA/OPPT Automobile Spray Coating Inhalation Exposure Model
• EPA/OPPT UV Roll Coating Inhalation Model
• User-Defined Inhalation Model
The following models may be selected for sources/activities that result in dermal exposure from
touching liquid chemicals and/or wet surfaces:
• EPA/OPPT 1-Hand Dermal Contact with Liquid Model
• EPA/OPPT 2-Hand Dermal Contact with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• EPA/OPPT 2-Hand Dermal Immersion with Liquid Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
360
-------
ChemSTEER User Guide - Updated May 2015
• User-Defined Dermal Model
Models for Calculating Exposures to Solids
The following models may be selected for sources/activities that result in inhalation exposure to
dusts:
• EPA/OPPT Small Volume Solids Handling Inhalation Model
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA Total PNOR PEL-Limiting Model
• OSHA Respirable PNOR PEL-Limiting Model
• User-Defined Inhalation Model
Exposures from Touching Solid Chemicals and/or Dusty Surfaces
The following models may be selected for sources/activities that result in dermal exposure from
touching solid chemicals and/or dusty surfaces:
• EPA/OPPT Direct 2-Hand Dermal Contact with Solids Model
• EPA/OPPT 2-Hand Dermal Contact with Container Surfaces Model
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal
Exposure. September 2013.
• User-Defined Dermal Model
Models for Cak
The following models may be selected to calculate exposures based on exposure limits:
• OSHA PEL-Limiting Model for Substance-Specific Particulates
• OSHA PEL-Limiting Model for Substance-Specific Vapors
• OSHA Total PNOR PEL-Limiting Model
• OSHA Respirable PNOR PEL-Limiting Model
361
-------
ChemSTEER User Guide - Updated May 2015
Definitions and Terms
Abbreviations
The following list is a draft list of all parameter abbreviations and other key assessment-related
abbreviations used in ChemSTEER (as of September 30, 2013) and is in alphabetical order. In future
ChemSTEER User Guides, the definitions will be refined and standardized.
A [area (cm2)] - area of liquid pool. EPA/OPPT Mass Transfer Coefficient Model. EPA/OPPT
Penetration Model
ADD [average daily dose (mg/kg-day)] - output from all exposure models in ChemSTEER. Same
as LADD except uses AT rather than ATc. LADD from pages 3 and 4 of US EPA Memo entitled Draft
Guidance on LADDs and APDRs from Becky Brown, Chemical Engineering Branch, to Chemical
Engineering Branch Staff and Management. 6/21/93
ADMUaddtv [average daily mass of bath additive (kg/site-day)] - Averaged daily mass of the
bath additive used to replace intermittent losses from bath changes and daily losses from rinsing parts
from Electroplating Bath Additive Use operation.
ADMUchem [average daily mass of chemical in bath additive used to replace intermittent
losses from bath changes and daily losses from rinsing parts (kg/site-day)] - Averaged daily mass of
chemical in the bath additive used to replace intermittent losses from bath changes and daily losses
from rinsing parts. Electroplating Bath Additive Use.
AH [amount of material handled (kg/day)] - input to an inhalation model, amount (mass) of
solids/ powder containing the chemical handled by a worker in an activity (limited to up to 54 kg/
worker/ shift). EPA/OPPT Small Volume Solids Handling Inhalation Model
Amt [amount of chemical to which a loss fraction (LF) is applied (kg/site-day)] - input for many
release models. This amount is often equal to a key mass or container-related parameter for the
operation such as the mass of chemical per batch or per container. EPA/OPPT Bulk Transport Residual
Model. EPA/OPPT Drum Residual Model. EPA/OPPT Multiple Process Vessel Residual Model. EPA/OPPT
Single Vessel Residual Model. EPA/OPPT Small Container Residual Model. EPA/OPPT Solid Residuals in
Transport Containers Model. EPA/OPPT Water Saturation Loss Model. User-Defined Loss Rate Model.
APDR [average potential dose rate (mg/kg-day)] - output from all exposure models in
ChemSTEER from pages 3 and 4 of US EPA Memo entitled Draft Guidance on LADDs and APDRs from
Becky Brown, Chemical Engineering Branch, to Chemical Engineering Branch Staff and Management.
6/21/93
AR [annual release rate of assessed chemical (kg/year)] - output from all release models in
ChemSTEER; calculated by the equation AR = DR x Freq x NS, AR is for all sites combined
AT [averaging time (years)] - input to all exposure models to calculate ADD; default of EY. US
EPA Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical Engineering
Branch, to Chemical Engineering Branch Staff and Management. 6/21/93
ATc [averaging time - chronic (years)] - input to all exposure models to calculate LADD; default
of 70 assumed as a reasonably conservative value from pages 5 and 6 default values list of US EPA
Memo entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical Engineering Branch, to
Chemical Engineering Branch Staff and Management. 6/21/93
362
-------
ChemSTEER User Guide - Updated May 2015
atm [atmospheres] - unit of measure of pressure
AVPlow [low end of adjusted vapor pressure range (torr)] - bounding adjusted vapor pressure
value, below which ChemSTEER will not default to using vapor generation models for calculating
releases to air from and inhalation exposures to liquid materials; refer to the Preferences menu topic,
Vapor Model Activation
AVPhigh [high end of adjusted vapor pressure range (torr)] - bounding adjusted vapor pressure
value, above which ChemSTEER will not default to using any of the vapor generation models for
calculating releases to air from and inhalation exposures to liquid materials; refer to the Preferences
menu topic, Vapor Model Activation
AVPprod [adjusted vapor pressure of product material (torr)] - applied to the preferred
AVPrange to determine whether the vapor generation release and exposure models are applicable for
the operation; ChemSTEER will only execute these models by default when AVPprod is within AVPrange;
refer to the Vapor Model Activation topic
AVPrange [preferred range in adjusted vapor pressure values (torr)] - bounded by AVPlow and
AVPhigh; if a liquid material's adjusted vapor pressure (AVPrm or AVPprod) is within the range,
ChemSTEER will utilize default vapor generation models for calculating releases to air and worker
inhalation exposures; refer to the Preferences menu topic, Vapor Model Activation
AVPraw [adjusted vapor pressure of raw material (torr)] - applied to the preferred AVPrange to
determine whether the vapor generation release and exposure models are applicable for the operation;
ChemSTEER will only execute these models by default when AVPrmz is within AVPrange; refer to the
Operation Parameters Tab -> Shared Parameters/Factors Subtab topic
b [volumetric inhalation rate (m3/hour)] - input to most inhalation exposure models; default of
1.25 assumed as a reasonably conservative value (slightly above "light work" rate) based on Table 4-1 of
Chapter 4 of Chemical Engineering Branch Manual for the Preparation of Engineering Assessments.
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991
BMIchem [batch mass input of chemical (kg/site-btc)] - input or output for batch operations in
the Mass Balance Parameters subtab; input, either alone or in combination with other batch
parameters, as option(s) for Amt for release models using loss fractions (LF) and for exposure models
using amount handled (AH). EPA/OPPT Bulk Transport Residual Model, EPA/OPPT Drum Residual Model,
EPA/OPPT Multiple Process Vessel Residual Model, EPA/OPPT Single Vessel Residual Model, EPA/OPPT
Small Container Residual Model, EPA/OPPT Solid Residuals in Transport Containers Model, EPA/OPPT
Water Saturation Loss Model, User-Defined Loss Rate Model; EPA/OPPT Small Volume Solids Handling
Inhalation Model
BMIrm [batch mass input of raw material (kg/site-btc)] - input or output for batch operations
in the Mass Balance Parameters subtab; input, either alone or in combination with other batch
parameters, to equations used in Container Parameter subtab value calculations
BMOchem [batch mass output of chemical (kg/site-btc)] - input or output for batch operations
in the Mass Balance Parameters subtab; input, either alone or in combination with other batch
parameters, as option(s) for Amt for release models using loss fractions (LF) and for exposure models
using amount handled (AH). EPA/OPPT Bulk Transport Residual Model, EPA/OPPT Drum Residual Model,
EPA/OPPT Multiple Process Vessel Residual Model, EPA/OPPT Single Vessel Residual Model, EPA/OPPT
Small Container Residual Model, EPA/OPPT Solid Residuals in Transport Containers Model, EPA/OPPT
Water Saturation Loss Model, User-Defined Loss Rate Model; EPA/OPPT Small Volume Solids Handling
Inhalation Model
363
-------
ChemSTEER User Guide - Updated May 2015
BMOprod [batch mass output of product (kg/site-btc)] - input or output for batch operations in
the Mass Balance Parameters subtab; input, either alone or in combination with other batch
parameters, to equations used in Container Parameter subtab value calculations
BW [body weight (kg)] - input to all exposure models to calculate LADD, ADD, ADPR; default of
70 assumed as a reasonably conservative value from pages 5 and 6 default values list of US EPA Memo
entitled Draft Guidance on LADDs and APDRs from Becky Brown, Chemical Engineering Branch, to
Chemical Engineering Branch Staff and Management. 6/21/93
C (or °C) [degrees Celsius] - unit of measure of temperature
CF [correction factor (dimensionless)] - a factor that the user may use to adjust the amount
released to account for: a) multiples of an amount (Amt) of water (e.g., for multiple washings); b) known
or estimated correction of the water solubility of the chemical; and/or c) other corrections; EPA/OPPT
Water Saturation Loss Model
Cm [mass concentration of chemical in air (mg/m3)] - input and/ or output from all inhalation
exposure models; EPA/OPPT Small Volume Solids Handling Inhalation Model, EPA/OPPT Mass Balance
Inhalation Model, OSHA PEL-Limiting Model for Substance-Specific Particulates, OSHA PEL-Limiting
Model for Substance-Specific Vapors, OSHA Total PNOR PEL-Limiting Model, OSHA Respirable PNOR PEL-
Limiting Model, User-Defined Inhalation Model
cm2 [square centimeters] - unit of measure of surface area
Cv [volumetric concentration of chemical in air (ppm)] - input and/ or output from all vapor
inhalation exposure models; EPA/OPPT Mass Balance Inhalation Model, OSHA PEL-Limiting Model for
Substance-Specific Vapors, User-Defined Inhalation Model
Cvk [volumetric vapor concentration of the chemical with an OSHA PEL in air (ppm)] - input to
one inhalation exposure model. OSHA PEL-Limiting Model for Substance-Specific Vapors
d [diameter of opening or exposed pool of liquid (cm)] - input to release models that estimate
vapor generation from open liquid pools. EPA/OPPT Mass Transfer Coefficient Model, EPA/OPPT
Penetration Model
Dbath: Density of the electroplating bath (kg/liter). Electroplating Bath Additive Use operation.
Dchem [density of the pure chemical (kg/L)] - input for making volume-to-mass conversions in
equations used in Container Parameter subtab value calculations
Dexp [Dermal potential dose rate of the assessed chemical (mg/day)] - output from all dermal
exposure models in ChemSTEER; input to all dermal exposure models to calculate LADD, ADD, ADPR
Di [density of material handled in a particular activity (kg/L)] - input for making volume-to-
mass conversions in equations used in Container Parameter subtab value calculations
DMIchem [daily mass input of chemical (kg/site-day)] - input or output for continuous
operations in the Mass Balance Parameters subtab; input, either alone or in combination with other
batch parameters, as option(s) for Amt for release models using loss fractions (LF) and for exposure
models using amount handled (AH). EPA/OPPT Bulk Transport Residual Model, EPA/OPPT Drum Residual
Model, EPA/OPPT Multiple Process Vessel Residual Model, EPA/OPPT Single Vessel Residual Model,
EPA/OPPT Small Container Residual Model, EPA/OPPT Solid Residuals in Transport Containers Model,
EPA/OPPT Water Saturation Loss Model, User-Defined Loss Rate Model; EPA/OPPT Small Volume Solids
Handling Inhalation Model
364
-------
ChemSTEER User Guide - Updated May 2015
DMIppaint [daily mass input of purchased paint (kg/site-day)] - mass balance input parameter
for the Automobile Refinish Spray Coating Application operation; input, either alone or in combination
with other parameters, to the equations used in Container Parameters subtab calculations
DMIrm [daily mass input of raw material (kg/site-day)] - input or output for continuous
operations in the Mass Balance Parameters subtab; input, either alone or in combination with other
batch parameters, to equations used in Container Parameter subtab value calculations
DMOchem [daily mass output of chemical (kg/site-day)] - input or output for continuous
operations in the Mass Balance Parameters subtab; input, either alone or in combination with other
batch parameters, as option(s) for Amt for release models using loss fractions (LF) and for exposure
models using amount handled (AH). EPA/OPPT Bulk Transport Residual Model, EPA/OPPT Drum Residual
Model, EPA/OPPT Multiple Process Vessel Residual Model, EPA/OPPT Single Vessel Residual Model,
EPA/OPPT Small Container Residual Model, EPA/OPPT Solid Residuals in Transport Containers Model,
EPA/OPPT Water Saturation Loss Model, User-Defined Loss Rate Model; EPA/OPPT Small Volume Solids
Handling Inhalation Model
DMOprod [daily mass output of product (kg/site-day)] - input or output for continuous
operations in the Mass Balance Parameters subtab; input, either alone or in combination with other
batch parameters, to equations used in Container Parameter subtab value calculations
DMP [default model processing] - function in ChemSTEER that adds default models to each
source/activity, based on the conditions in the assessment
DMUchem [daily mass of chemical used (kg/site-day)] - input or output for the Automobile
OEM Spray Coating Application and the Automobile Refinish Spray Coating Application operations in the
Mass Balance Parameters subtab (DMUchem is a non-default for the Auto Refinish Spray Coating
operation); input, either alone or in combination with other batch parameters, as option(s) for Amt for
release models using loss fractions (LF) and for exposure models using amount handled (AH). EPA/OPPT
Bulk Transport Residual Model, EPA/OPPT Drum Residual Model, EPA/OPPT Multiple Process Vessel
Residual Model, EPA/OPPT Single Vessel Residual Model, EPA/OPPT Small Container Residual Model,
EPA/OPPT Solid Residuals in Transport Containers Model, EPA/OPPT Water Saturation Loss Model, User-
Defined Loss Rate Model; EPA/OPPT Small Volume Solids Handling Inhalation Model
DMUfpaint [daily mass of formulated paint used (kg/site-day)] - input or output for the
Automobile Refinish Spray Coating Application operation in the Mass Balance Parameters subtab; only
used in cases where the user elects an effluent basis for the operation Mass Balance Parameter
calculations (this is the non-default option for this operation)
DMUpaint [daily mass of paint used (kg/site-day)] - input or output for the Automobile OEM
Spray Coating Application operation in the Mass Balance Parameters subtab
Dppaint [density of purchased paint (kg/L)] - mass balance input parameter for making volume-
to-mass conversions in the Automobile Refinish Spray Coating Application operation; used with
DVIppaint to calculate DMIppaint
Dprod [density of product material (kg/L)] - input for making volume-to-mass conversions in
equations used in Container Parameter subtab value calculations
DR [daily release rate (kg/site-day)] - model output for every release model in ChemSTEER;
calculated by the relevant model equation
365
-------
ChemSTEER User Guide - Updated May 2015
Drinse [density of the electroplating rinse (kg/liter)] Electroplating Bath Additive Use
operation.
Drm [density of raw material (kg/L)] - input for making volume-to-mass conversions in
equations used in Container Parameter subtab value calculations
DVIppaint [daily volume of purchased paint used (liters/site-day)] - input to the Automobile
Refinish Spray Coating Application operation in the Mass Balance Parameters subtab; input with Dppaint
to calculate DMIppaint
DVrinse: [daily volume of rinse water generated per site (gallons/site-day)] Electroplating Bath
Additive Use operation.
ED [days exposed per year (days/site-year)] - input and output from all exposure models
EF [exposure factor (mg/kg)] - mg of solid material inhaled per kg handled; EPA/OPPT Small
Volume Solids Handling Inhalation Model
EPVop [estimated PVop for iterative calculation sequences]. Electroplating Bath Additive Use
operation.
EY [years of occupational exposure (years)] - input to all exposure models in ChemSTEER;
default of 40 assumed as a reasonably conservative value from pages 5 and 6 of US EPA Memo entitled
Draft Guidance on LADDs and APDRs from Becky Brown, Chemical Engineering Branch, to Chemical
Engineering Branch Staff and Management. 6/21/93
f [saturation factor (dimensionless)] - input to release models in ChemSTEER that estimate
vapor generation from vapor displacement, such as filling containers with liquids.EPA/OAQPS AP-42
Loading Model
fc [fraction of PVop shipped in a particular container (dimensionless)] - input to equations used
in Container Parameter subtab value calculations
Percent of PV [PERCENT of {total} production volume (PV) associated with a particular
operation (dimensionless)] - "Percent of PV" x PV / 100 = PVop (see Operation, Operations Tab ->
Relationships Subtab)
Freq [frequency of release (days/site-yr)] - input and output from all release models
Freqbath [frequency of bath changes per year (changes/bath/yr)]. Electroplating Bath Additive
Use operation.
FT [frequency of dermal events (events/day)] - input to all dermal exposure models
g [grams] - unit of measure of mass
G [vapor generation rate of the assessed chemical (g/s, grams/second)] - input or output from
all release models that estimate vapor generation. EPA/OAQPS AP-42 Loading Model, EPA/O PPT Mass
Transfer Coefficient Model, EPA/OPPT Penetration Model, User-Defined Vapor Generation Rate Model
h [exposure duration (hrs/day)] - input or output from equations used in Container Parameter
subtab value calculations; input to all inhalation exposure models EXCEPT EPA/OPPT Small Volume
Handling Model, which does not have a time factor. EPA/OPPT Mass Balance Inhalation Model, OSHA
PEL-Limiting Model for Substance-Specific Particulates, OSHA PEL-Limiting Model for Substance-Specific
Vapors, OSHA Total PNOR PEL-Limiting Model, OSHA Respirable PNOR PEL-Limiting Model, User-Defined
Inhalation Model
366
-------
ChemSTEER User Guide - Updated May 2015
HB [hours per batch (hrs/btc)] - input or output for batch operations in the Mass Balance
Parameters subtab
hr [hours] - unit of measure of time
i [activity designator] - indicates that the accompanying parameter may have a value that is
particular to the source/activity being assessed
I [inhalation potential dose rate of the assessed chemical (mg/day)] - output from all inhalation
exposure models in ChemSTEER; input to all inhalation exposure models to calculate LADD, ADD, ADPR
IRER [Initial Review Engineering Report] - a specially formatted EPA report for internal use for
summarizing estimates of workplace (operation) releases and exposures in a particular assessment. IRER
Format Details
K [degrees Kelvin] - unit of measure of temperature
k [mixing factor (dimensionless)] - used by the EPA/OPPT Mass Balance Inhalation Model
KCk [mass concentration of total or total respirable particulate in the air (mg/m3)] - input to
all OSHA PEL particulate-related inhalation exposure models. OSHA PEL-Limiting Model for Substance-
Specific Particulates, OSHA Total PNOR PEL-Limiting Model, OSHA Respirable PNOR PEL-Limiting Model
Kg [kilograms] - unit of measure of mass
L [liters] - unit of measure of volume
LADD [lifetime average daily dose (mg/kg-day)] - output from all exposure models in
ChemSTEER from pages 3 and 4 of US EPA Memo entitled Draft Guidance on LADDs and APDRs from
Becky Brown, Chemical Engineering Branch, to Chemical Engineering Branch Staff and Management.
6/21/93
LF [loss fraction (dimensionless) applied to a given amount (Amt) of chemical] - input to many
release models. This loss is often based on data or another assumption and then multiplied by a given
amount (mass) of chemical per batch or per container. EPA/OPPT Bulk Transport Residual Model,
EPA/OPPT Drum Residual Model, EPA/OPPT Multiple Process Vessel Residual Model, EPA/OPPT Single
Vessel Residual Model, EPA/OPPT Small Container Residual Model, EPA/OPPT Solid Residuals in
Transport Containers Model, EPA/OPPT Water Saturation Loss Model, User-Defined Loss Rate Model.
Ls [number of manufacturing/ processing/ use lines per site (lines/site)] - input or output for
batch operations in the Mass Balance Parameters subtab; input in combination with other batch
parameters as option(s) for Amt for cleaning-related release models using loss fractions (LF) and for
exposure models using amount handled (AH). EPA/OPPT Bulk Transport Residual Model, EPA/OPPT
Drum Residual Model, EPA/OPPT Multiple Process Vessel Residual Model, EPA/OPPT Single Vessel
Residual Model, EPA/OPPT Small Container Residual Model, EPA/OPPT Solid Residuals in Transport
Containers Model, EPA/OPPT Water Saturation Loss Model, User-Defined Loss Rate Model; EPA/OPPT
Small Volume Solids Handling Inhalation Model
m [meters] - unit of measure of length
ml [square meters] - unit of measure of surface area
m3 [cubic meters] - unit of measure of volume
MCi [mass of material in container handled in a particular activity (kg/container)] - input or
output in the Container Parameter subtab; input in combination with other container parameters as
option(s) for Amt for container-related release models using loss fractions (LF) and for exposure models
367
-------
ChemSTEER User Guide - Updated May 2015
using amount handled (AH). EPA/OPPT Bulk Transport Residual Model, EPA/OPPT Drum Residual Model,
EPA/OPPT Small Container Residual Model, EEPA/OPPT Solid Residuals in Transport Containers Model,
User-Defined Loss Rate Model; EPA/OPPT Small Volume Solids Handling Inhalation Model
McE [spray mist capture efficiency (dimensionless)] - portion of the sprayed mist that is
captured out of the air by the spray booth technology; used in the EPA/OPPT Automobile OEM Coating
Oversprav Loss Model
mg [milligrams] - unit of measure of mass
mi [miles] - unit of measure of length
min [minutes] - unit of measure of time
MW [molecular weight of the chemical (g/mol)] - input for the Chemical tab; input to all release
models that estimate vapor generation using derived mathematical models; input to all inhalation
exposure models that use the parameter Cv (MW is used to convert to Cm). EPA/OAQPS AP-42 Loading
Model, EPA/OPPT Mass Transfer Coefficient Model, EPA/OPPT Penetration Model; EPA/OPPT Mass
Balance Inhalation Model, OSHA PEL-Limiting Model for Substance-Specific Vapors, User-Defined
Inhalation Model
MWpel [molecular weight of the chemical with an OSHA PEL that is in the mixture with the
assessed chemical (g/mol)] - input for one OSHA PEL substance-specific vapor inhalation exposure
model. OSHA PEL-Limiting Model for Substance-Specific Vapors
Nbath [number of bath tanks per site (baths/site)]. Electroplating Bath Additive Use operation.
Nbd [number of batches per site per day (btc/site-day)] - input or output for batch operations
in the Mass Balance Parameters subtab; input in combination with other batch parameters as option(s)
for Amt for cleaning-related release models using loss fractions (LF) and for exposure models using
amount handled (AH). EPA/OPPT Bulk Transport Residual Model, EPA/OPPT Drum Residual Model,
EPA/OPPT Multiple Process Vessel Residual Model, EPA/OPPT Single Vessel Residual Model, EPA/OPPT
Small Container Residual Model, EPA/OPPT Solid Residuals in Transport Containers Model, EPA/OPPT
Water Saturation Loss Model, User-Defined Loss Rate Model; EPA/OPPT Small Volume Solids Handling
Inhalation Model
Nbld [number of batches per line per day (btc/line-day)] - input or output for batch operations
in the Mass Balance Parameters subtab
Near [number of cars painted per day (cars/site-day)] - input parameter for the Automobile
OEM Spray Coating Application operation in the Mass Balance Parameters subtab to determine
DMUpaint value
Ned [number of containers per site per day (containers/site-day)] - input or output in the
Container Parameter subtab; input in combination with other batch parameters as option(s) for Amt for
container-related release models using loss fractions (LF) and for exposure models using amount
handled (AH). EPA/OPPT Bulk Transport Residual Model, EPA/OPPT Drum Residual Model, EPA/OPPT
Multiple Process Vessel Residual Model, EPA/OPPT Single Vessel Residual Model, EPA/OPPT Small
Container Residual Model, EPA/OPPT Solid Residuals in Transport Containers Model, EPA/OPPT Water
Saturation Loss Model, User-Defined Loss Rate Model; EPA/OPPT Small Volume Solids Handling
Inhalation Model
368
-------
ChemSTEER User Guide - Updated May 2015
Nby [number of batches per site per year (btc/site-yr)] - input or output for batch operations in
the Mass Balance Parameters subtab; input as option for Freq for most release models and as option for
ED for most exposure models
Ncy [number of containers per year (containers/site-yr)] - input or output for the Operation
Parameters Tab -> Container Parameters Subtab as an option for frequency of release (Freq) for release
models, as well as for exposure days (ED) for exposure models
NS [number of sites (sites)] - input or output for all operations in the Mass Balance Parameters
subtab; input and output from all release models
NWexp [number of exposed workers for the source/ activity per site] - defaults to 3 for most
models, and the same value applies to each exposure model for a given source/ activity (e.g., changing
the value of NWexp in the dermal model changes the NWexp in the inhalation model to the same
value); the appropriate values of 17 for the Auto OEM Spray Coating Inhalation model and 3 for the
Auto Refinish Spray Coating Inhalation model have not been incorporated into ChemSTEER; the logic
and appropriate default values for this parameter will be finalized in the next version of ChemSTEER
OD [operating days per site per year (days/site-yr)] - input or output for all operations in the
Mass Balance Parameters subtab; input as option for Freq for all release models and as option for ED for
all exposure models
ODa [operating days per site per year for a particular activity (days/site-yr)] - input or output
in the Container Parameter subtab; input as option for Freq for all container-related release models and
as option for ED for all container-related exposure models
ODmax [maximum number of operating days possible for batch operations (days/site-yr)] -
input used as a limitation in calculating OD for batch operations in the Mass Balance Parameters subtab
OHa [operating hours per site per day for a particular activity (hrs/site-day)] - input or output
in the Container Parameter subtab; input as option for OHa for many release models and as option for h
for many exposure models
P [total ambient air pressure (torr)] - input to one vapor generation release model. EPA/OPPT
Penetration Model.
ppm [parts per million] - unit of measure for concentration
PV [total production volume of the assessed chemical (kg/yr)] - the overall "volume" of the
assessed chemical (in units of mass per time, kg/yr) assessed using ChemSTEER; PV = PVd + PVi (see
Chemical Properties Tab.
PVd [volume of the chemical manufactured domestically (kg/yr)] - PV = PVd + PVi (see
Chemical Properties Tab)
PVf [PERCENT of the total production volume (PV) associated with a particular operation
(dimensionless)] - see description of Percent ofPV, above
PVi [imported volume of the chemical (kg/yr)] - PV = PVd + PVi (see Chemical Properties Tab)
PVop [production volume associated with a particular operation (kg/yr)] (see Operations Tab
-> Relationships Subtab)
Q [ventilation rate (ft3/min)] - used by the EPA/O PPT Mass Balance Inhalation Model
Qu [quantity of chemical remaining on skin (mg/cm2-event)] - input to all dermal exposure
models
369
-------
ChemSTEER User Guide - Updated May 2015
r [rate of loading/unloading of containers (containers loaded/hour) or (gallons
unloaded/min)] - input or output in the Container Parameter subtab; input to one vapor generation
release model. EPA/OAQPS AP-42 Loading Model
R [universal gas constant (82.05 atm cm3/gmol K)] - input to one vapor generation release
model. EPA/OAQPS AP-42 Loading Model
RinseE [rinsewater recovery efficiency (dimensionless)] Electroplating Bath Additive Use
operation.
S [surface area (cm2)] - input to release models that estimate vapor generation from open
liquid pools, EPA/OPPT Mass Transfer Coefficient Model, EPA/OPPT Penetration Model
Sd [number of shifts worked by each worker per day (shifts/worker-day)] - used to scale the
inhalation exposure of workers handling small volumes of solids; EPA/OPPT Small Volume Solids
Handling Inhalation Model
sec [seconds] - unit of measure of time
SrE [solids removal efficiency (dimensionless)] - fraction of the total solids removed from
captured oversprayed paint mist; defaults dependent upon the spray booth technology (i.e., waterwash
or dry filter); used by the EPA/OPPT Automobile OEM Coating Overspray Loss Model
T [temperature (K)] - input to all release models that estimate vapor generation using derived
mathematical models. EPA/OAQPS AP-42 Loading Model, EPA/OPPT Mass Transfer Coefficient Model,
EPA/OPPT Penetration Model
TE [spray gun transfer efficiency (dimensionless)] - portion of the sprayed coating that adheres
to the target surface; dependent upon the type of spray gun (i.e., conventional or HVLP); EPA/OPPT
Automobile OEM Coating Overspray Loss Model
TWA [time-weighted average] - an average value over the particular time period, usually
referring to exposure duration (h) in exposure models
Vbath [volume of solution per electroplating bath (gallons/bath)]. Electroplating Bath Additive
Use operation.
Vc [volume of the container (gal)] - input or output in the Container Parameter subtab; input to
release models that estimate vapor generation from vapor displacement, such as filling containers with
liquids. EPA/OAQPS AP-42 Loading Model
Vcar [volume of paint used per car (liters/car)] - input for the Automobile OEM Spray Coating
Application operation in the Mass Balance Parameters subtab; used with Dprod and Near to calculate
DMUpaint
Vm [molar volume of gas (L/mol)] - input to all inhalation exposure models that use the
parameter Cv (Vm used to convert to Cm); default value of 24.45 assumes ambient conditions of 25°C
and 1 atm. EPA/OPPT Mass Balance Inhalation Model; OSHA PEL-Limiting Model for Substance-Specific
Vapors, User-Defined Inhalation Model
Vpaint [volume of paint used per day (gallons/site-day)] - input for the Automobile OEM Spray
Coating Application operation in the Mass Balance Parameters subtab; used with Dprod and a
conversion of gallons to liters to calculate DMUpaint
VPchem [vapor pressure of the pure chemical (torr)] - input for the Chemical tab; input to all
release models that estimate vapor generation using derived mathematical models; input to equation
370
-------
ChemSTEER User Guide - Updated May 2015
for calculating the maximum possible volumetric vapor concentration for two inhalation exposure
models. EPA/OAQPS AP-42 Loading Model, EPA/OPPT Mass Transfer Coefficient Model, EPA/OPPT
Penetration Model; EPA/OPPT Mass Balance Inhalation Model, OSHA PEL-Limiting Model for Substance-
Specific Vapors
VPpel [vapor pressure of the chemical with an OSHA PEL that is in the mixture with the
assessed chemical (torr)] - input for the OSHA PEL-Limiting Model for Substance-Specific Vapors
vz [air speed (ft/min)] - input to release models that estimate vapor generation from open
liquid pools; input to equation for calculating ventilation rate default for one inhalation exposure model.
EPA/OPPT Mass Transfer Coefficient Model, EPA/OPPT Penetration Model, EPA/OPPT Mass Balance
Inhalation Model
WSchem [water solubility of the pure chemical (g/L)] - input for the Chemical tab; input to one
release model. EPA/OPPT Water Saturation Loss Model
X [vapor pressure correction factor (dimensionless)] - input to all release models that estimate
vapor generation using derived mathematical models and having the VP parameter; input to equation
for calculating the maximum possible volumetric vapor concentration for two inhalation exposure
models. . EPA/OAQPS AP-42 Loading Model, EPA/OPPT Mass Transfer Coefficient Model, EPA/OPPT
Penetration Model, EPA/OPPT Mass Balance Inhalation Model; OSHA PEL-Limiting Model for Substance-
Specific Vapors.
Xother [vapor pressure correction factor for process material that is neither raw material, nor
product (dimensionless)] - input (as a possible non-default value for X) to vapor generation release
models using derived mathematical models and having the VP parameter; input to calculation for
calculating the maximum possible volumetric vapor concentration for two inhalation exposure models.
EPA/OAQPS AP-42 Loading Model, EPA/OPPT Mass Transfer Coefficient Model, EPA/OPPT Penetration
Model; EPA/OPPT Mass Balance Inhalation Model, OSHA PEL-Limiting Model for Substance-Specific
Vapors. Default options for calculating Xother are contained in the Operation Parameters Tab -> Shared
Parameters/Factors Subtab.
Xprod [vapor pressure correction factor for the product material (dimensionless)] - input (as a
possible default value for X) to vapor generation release models using derived mathematical models and
having the VP parameter; input to calculation for calculating the maximum possible volumetric vapor
concentration for two inhalation exposure models. EPA/OAQPS AP-42 Loading Model, EPA/OPPT Mass
Transfer Coefficient Model, EPA/OPPT Penetration Model; EPA/OPPT Mass Balance Inhalation Model,
OSHA PEL-Limiting Model for Substance-Specific Vapors. Default options and calculating for Xprod are
contained in the Operation Parameters Tab -> Shared Parameters/Factors Subtab.
Xrm [vapor pressure correction factor for the raw material (dimensionless)] - input (as a
possible default value for X) to vapor generation release models using derived mathematical models and
having the VP parameter; input to calculation for calculating the maximum possible volumetric vapor
concentration for two inhalation exposure models. EPA/OAQPS AP-42 Loading Model, EPA/OPPT Mass
Transfer Coefficient Model, EPA/OPPT Penetration Model; EPA/OPPT Mass Balance Inhalation Model,
OSHA PEL-Limiting Model for Substance-Specific Vapors. Default options and calculating for Xprod are
contained in the Operation Parameters Tab -> Shared Parameters/Factors Subtab.
Yaddtv [weight fraction of the chemical in the electroplating batch additive (dimensionless)].
Electroplating Bath Additive Use.
Ybath [weight fraction of the chemical in the electroplating bath (dimensionless)].
Electroplating Bath Additive Use.
371
-------
ChemSTEER User Guide - Updated May 2015
Yderm [weight fraction of the chemical in liquid or solid (dimensionless)] - input to all dermal
exposure models
Yfpaint [weight fraction of the chemical in the formulated paint (dimensionless)] - input
parameter for the Automobile Refinish Spray Coating Application operation; only used in cases where
the user elects an effluent basis for the operation Mass Balance Parameter calculations (this is the non-
default option for this operation); used by inhalation and dermal exposure models
Yi [weight fraction of the chemical in material handled in a particular activity (dimensionless)]
- input or output in the Container Parameter subtab; input in combination with other container
parameters as option(s) for Amt for container-related release models using loss fractions (LF); input for
inhalation exposure models using amount handled (AH) or OSHA PELs for container-related sources/
activities, and for all dermal models for container-related sources/ activities. EPA/OPPT Bulk Transport
Residual Model, EPA/OPPT Drum Residual Model, EPA/OPPT Small Container Residual Model, EPA/OPPT
Solid Residuals in Transport Containers Model, User-Defined Loss Rate Model; EPA/OPPT Small Volume
Solids Handling Inhalation Model, OSHA PEL-Limiting Model for Substance-Specific Particulates, OSHA
PEL-Limiting Model for Substance-Specific Vapors, OSHA Total PNOR PEL-Limiting Model, OSHA
Respirable PNOR PEL-Limiting Model
Yliq [weight fraction of the chemical in liquid (dimensionless)] - input to all dermal exposure
models
Ypaint [weight fraction of the chemical in the paint (dimensionless)] - input and output for the
Automobile OEM Spray Coating Application operation in the Mass Balance Parameters subtab; used by
the inhalation and dermal exposure models
Ypel [weight fraction of the chemical with an OSHA PEL that is in the particulate or mixture
with the assessed chemical (dimensionless)] - input for all OSHA PEL substance-specific inhalation
exposure models. OSHA PEL-Limiting Model for Substance-Specific Particulates, OSHA PEL-Limiting
Model for Substance-Specific Vapors
Yppaint [weight fraction of the chemical in the purchased paint (dimensionless)] - input and
output for the Automobile Refinish Spray Coating Application operation in the Mass Balance Parameters
subtab; used by the inhalation and dermal exposure models
Yprod [weight fraction of the chemical in the product (dimensionless)] - input or output for all
operations in the Mass Balance Parameters subtab; input as default for Yi for product related container
sources/ activities in the Container Parameter subtab; input as option for Ys and Yderm for most
exposure models
yr [years] - unit of time
Yrinse [weight fraction of the chemical in the electroplating batch rinse water
(dimensionless)]. Electroplating Bath Additive Use operation.
Yrm [weight fraction of the chemical in the raw material (dimensionless)] - input or output for
all operations in the Mass Balance Parameters subtab; input as default for Yi for product related
container sources/ activities in the Container Parameter subtab; input as option for Ys and Yderm for
most exposure models
Ys [weight fraction of the chemical in particulate or mixture (dimensionless)] - input for all
particulate and OSHA PEL inhalation exposure models. EPA/OPPT Small Volume Solids Handling
Inhalation Model, EPA/OPPT Mass Balance Inhalation Model, OSHA PEL-Limiting Model for Substance-
372
-------
ChemSTEER User Guide - Updated May 2015
Specific Particulates, OSHA PEL-Limiting Model for Substance-Specific Vapors. OSHA Total PNOR PEL-
Limiting Model, OSHA Respirable PNOR PEL-Limiting Model
Ysf [weight fraction of the solids within the paint (dimensionless)] - used in the EPA/OPPT
Automobile Spray Coating Inhalation Exposure Model
ChemSTEER Terms
The following list includes many of the key terms used in ChemSTEER and is in alphabetical
order. In future ChemSTEER User Guides, you will be able to click on the link of interest following a
term's description to access information about the term and how it is used in ChemSTEER.
Activity - see Release Source/ Exposure Activity definition below.
Chemical - the chemical being assessed.
Dermal - skin
Exposure - contact of the assessed chemical with a boundary of a human. In ChemSTEER, the
human is a worker, and the boundaries are the respiratory and upper digestive tracts for inhalation
exposure and the skin, usually one or both hands, for dermal exposure.
Exposure Activity - see Release Source/Exposure Activity definition below.
Percent of PV - PERCENT of the assessed volume (PV) that flows to or from the operation. For
example, if a manufacturing operation (User-defined Manufacturing) produces all of the assessed
volume, then the Percent of PV for User-defined Manufacturing is 100 (100%). If there are two primary
use operations (User-defined Use and User-defined Use 2) that use the chemical, and three quarters is
used by the first use operation and the remainder by the second use operation, then the Percent of PV
for User-defined Use is 75 (75%) and the Percent of PV for User-defined Use 2 is 25 (25%). (see
Operations Tab -> Relationships Subtab)
Input (to a model or to another equation in ChemSTEER) - a parameter or value of a parameter
used in a release or exposure model equation or to an equation used in ChemSTEER to calculate a result
(output) from one or more equations calculating release or exposure related parameter values.
Manufacturing - generally represents an operation in which the chemical being assessed is
created or formed in a reaction.
Method - synonymous with Model
Model - an equation or set of equations containing parameters related to chemical- and
operation-specific factors, and the equation(s) are used to calculate estimated amounts (quantities) of
release of and worker exposure to the assessed chemical.
Operation - a workplace or set of "homogeneous" workplaces with essentially the same (or
similar) processes, equipment, chemical throughputs, procedures, and worker populations, such that
estimates of releases and exposures to the chemical being assessed can be assumed to be essentially
the same for all of the workplaces, if more than one, in the set. If workplaces differ in some aspects that
could result in significantly different estimates of releases and exposures, you should assess these
workplaces as two or more separate operations.
373
-------
ChemSTEER User Guide - Updated May 2015
Output (from a model or from another equation in ChemSTEER) - a parameter or value (result)
of a parameter calculated using one or more equations in a release or exposure model or from an
equation used in ChemSTEER to generate release or exposure related parameter values.
Processing - generally represents an operation in which the chemical being assessed is not
created or formed and in which the chemical being assessed is not destroyed or transformed in a
chemical reaction, or otherwise becomes essentially unavailable for further release or exposure.
Formulation and repackaging operations would usually be considered to be types of Processing
operations.
Product - material leaving the operation, whether pure chemical or chemical in a mixture. The
product from an operation is assumed to be the raw material of any subsequent operation(s).
Production Volume - the overall "volume" of the assessed chemical (in units of mass per time,
kg/yr) assessed using ChemSTEER; PV = PVd + Pvi. (see Chemical Properties Tab)
Raw Material - material entering the operation, whether pure chemical or chemical in a
mixture. The product from an operation is assumed to be the raw material of any subsequent
operation(s).
Relationship - how different workplaces are related as suppliers and customers. A customer's
operation receiving the chemical being assessed, whether pure or in a mixture with other chemicals,
from a supplier makes the customer's operation a subsequent operation to the supplier's operation.
Release (environmental release) - chemical emission or disposal to the environment or to
treatment or disposal facilities outside of the operation.
Release Source/ Exposure Activity - sources and activities in an operation that can/ do/ will
cause releases to the environment and/ or worker exposures. Most Source/ Activities have one or more
default models that ChemSTEER uses to estimate releases and exposures. Choosing appropriate Source/
Activities allow you to access models to make these estimates.
Result - see Output definition above.
TWA - time-weighted average, usually referring to exposure duration (h).
Use - generally represents an operation in which the chemical being assessed destroyed or
transformed in a chemical reaction, or otherwise becomes essentially unavailable for further release or
exposure.
374
-------
ChemSTEER User Guide - Updated May 2015
References
The methods and models used in ChemSTEER are from several EPA sources, including the
"Chemical Engineering Branch Manual for the Preparation of Engineering Assessments" and other
reports and memoranda detailing the methods used in CEB assessments. References to the industry-
specific operations are taken from the "Chemical Engineering Branch Compilation of Generic Scenarios
for Chemical Uses." These references document the various empirical, mathematical, and suppositional
methods and models that have been developed and used by EPA over many years of workplace
exposure and release assessment.
Click on the following links to access the files containing copies of the relevant portions of these
references.
NOTE: These files are in Adobe's Portable Document Format (PDF). To view or print them you
will need to have the Adobe Acrobat Reader program installed on your computer. The Reader
can be downloaded and used with no charge; for more information at EPA about PDF files, click
the following link: http://www.epa.gov/epahome/pdf.html
US EPA Memo entitled Updating CEB's Method for Screening-Level Assessments of Dermal Exposure.
September 2013.
Pre-publication draft article entitled Evaporation of Pure Liquids From Open Surfaces. Fredric C. Arnold
and Alfred J. Engel, US EPA, October, 1999.
SAICfor US EPA/OPPT. Generic Scenario for Automobile Spray Coating Draft Report. August 1996.
SAICfor US EPA/OPPT. Generic Scenario: Electroplating. August 1996.
Fehrenbacher, M.C. and Hummel, A.A. "Evaluation of the Mass Balance Model Used by the
Environmental Protection Agency for Estimating Inhalation Exposure to New Chemical Substances".
American Industrial Hygiene Association Journal. June 1996. 57: 526-536.
Organization for Economic Co-operation and Development. Emission Scenario Document on Coating
Application via Spray Painting in the Automotive Refinishing Industry. June 2010.
US EPA Memo entitled Draft Guidance on LADDs and APDRs, from Becky Brown, Chemical Engineering
Branch, to Chemical Engineering Branch Staff and Management. 6/21/93.
US EPA Chemical Engineering Branch Generic Scenario entitled Textile Dyeing, 10/15/92.
US EPA Memo entitled Standard Assumptions for PMN Assessments, from the Chemical Engineering
Branch Quality Panel to Chemical Engineering Branch Staff and Management. 10/92.
Chapter 4 of Chemical Engineering Branch Manual for the Preparation of Engineering Assessments.
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991.
375
-------
ChemSTEER User Guide - Updated May 2015
Chapter 7 of the Chemical Engineering Branch Manual for the Preparation of Engineering Assessments;
Washington, DC; Office of Toxic Substances, U.S. Environmental Protection Agency; 1991; pp. 7-3
through 7-9.
Appendix K of Chemical Engineering Branch Manual for the Preparation of Engineering Assessments.
Washington, D.C.: Office of Toxic Substances, U.S. Environmental Protection Agency, 1991.
PEI Associates for US EPA/OTS. Releases During Cleaning of Equipment. July 1988.
Generic Scenario: Roll Coating of UV-Curable Coatings. No date.
Summary Sheet: Recirculating Water-Cooling Tower. No date.
US EPA Chemical Engineering Branch model entitled, Generic Model to Estimate Dust Releases from
Transfer/Unloading Operations of Solid Powders: July 20, 2007.
376
-------
ChemSTEER User Guide - Updated May 2015
Appendix A - Industry Specific Operations
The following sections provide details on the hardcoded industry-specific Generic Scenarios
included in ChemSTEER.
Automobile Original Equipment Manufacture (OEM) Spray Coating
Revised August 12, 2003. This operation is applicable to the use of a liquid coating product (e.g.,
paint) that is sprayed onto originally manufactured (i.e., new) automobile surfaces. It estimates the
releases and exposures to nonvolatile components of the coating only. The draft Generic Scenario for
Automobile Spray Painting, August 1996, was the primary reference source for the operation defaults
described below.
By default, this operation will assume the use of a conventional spray gun within a downdraft
spray booth having a waterwash curtain. These specifications determine default input parameter values
used by the release and exposure models. You may specify the spray gun type for the operation in the
Operation Parameters Tab Shared Parameters/Factors Subtab. Non-default values for model
parameters affected by the booth ventilation type and/or the overspray control device may be specified
at the Release or Exposure tab.
Operation tab / Description subtab
Selected NAICS (default)
The following NAICS codes are pre-selected for this operation:
• 3361 - Motor Vehicle Manufacturing
• 3362 - Motor Vehicle Body and Trailer Manufacturing
Process Description
NOTE: Release sources and exposure activities prior to the spray coating step of this operation
(e.g., unloading of containers, equipment cleaning) are not included and must be manually selected.
Pre-coating steps have not been researched, and those steps in the following description are presumed.
This operation assumes that the coating product is primarily applied via robotic devices and that
worker exposures during the coating step are the result of manual touch-up of parts damaged during
assembly.
The coating product is shipped to automotive OEM facilities in bulk containers (tank trucks,
totes, drums, etc.) Depending on the facility, the coating may be unloaded into a storage tank until use
or stored in the original container. Prior to the application, the coating may be further blended in a
mixing tank with other additives and solvent to achieve optimum viscosity and color.
377
-------
ChemSTEER User Guide - Updated May 2015
The formulated coating is than loaded to a feed tank connected to robotic controlled spray guns
and is spray applied onto cars. Painted cars are cured in a room where the temperature can reach 450F.
Several layers of coating are applied to car alternated with heating to cure the coating or drive off
moisture. After the curing, no further exposure to or release of the coating are expected.
Although the automobile OEM spray coating process is highly automated, some "touch-ups" are
expected including the repair of scratches and damages that may result during the assembly activities.
These repairs are usually performed by workers using spray guns in downdraft booths.
Worker exposure to paint may occur during transfer of coatings from shipping containers to a
storage tank, blending of coating, manual spray application, and clean-up. Sources for potential
environmental releases include stack air release during the spray application, solid and aqueous waste
of oversprayed mist, clean-up waste and empty containers.
The default process description for this operation is as follows:
Unload coating product containing the assessed chemical from shipping container ->
Mix and/or store (optional) -> Transfer to spray gun feed system -> Apply coating to
automobile surfaces (some sprayed coating does not remain on the surfaces - it passes
into the booth ventilation system and is either captured in exhaust controls or is
exhausted into the air through the stack) -> Bake/cure coating at high temperatures
(assessed chemical is destroyed or fixed to the coated surface).
Oper 'urces/Activities subtab
The following default source/activity is automatically listed on the Sources/Activities that will be
assessed in the operation list on the Update Operation Sources/Activities screen (launched by the
Update Sources/Activities button):
• Automobile OEM Spray Coating Application (Exposure - Yes. Release - Yes)
Available Activities:
• All other activities
Clicking the Update Parameters button on the Mass Balance Parameters subtab launches the
Update Operation Mass Balance Parameter screen. The following logic defines the default conditions
and parameter values for this screen.
Mass Balance Basis Selection tab
Default selections are Continuous and Formulated Paint Usage (where Formulated Paint Usage
replaces Product since the basis is actually the paint used rather than a true product).
Specify Mass Balance Input Parameters
378
-------
ChemSTEER User Guide - Updated May 2015
If you select a different basis other than the default basis selection (Continuous and Formulated
Paint Usage), ChemSTEER uses the logic and calculations associated with user-defined operations, which
are described in the Operation Parameters Tab -> Mass Balance Parameters Subtab pages of the User
Guide. You must manually make all mass balance calculations by substituting the parameters for
formulated paint used in place of standard product output parameters from that logic, and the logic and
default calculations below for this operation are not used.
If you retain the default basis selection (Continuous and Formulated Paint Usage), the
parameters listed below and the following logic are used to perform mass balance calculations.
Parameters
NOTE: The equivalent parameter in the Generic Scenario for Automobile Spray Coating, if
applicable, appears in parentheses.
DMIrm: Daily mass input of raw material (kg/site-day)
DMIchem: Daily mass input of the chemical (kg/site-day)
DMUfpaint: Daily mass of formulated coating used (DMUfpaint replaces DMOprod for user-
defined operations, but for the purpose of the mass balance is used in the same
way) (kg/site-day) (0 < DMUpaint)
DMUchem: Daily mass of chemical in the formulated coating used (DMUchem replaces
DMOchem for user-defined operations, but for the purpose of the mass balance
is used in the same way) (kg/site-day) (0 < DMUchem)
Yrm: Weight fraction of the chemical in raw material (0 < Yrm < 1; default: Yprod
from previous operation)
Yfpaint (C): Weight fraction of the chemical in the formulated paint (Yfpaint replaces Yprod
for user-defined operations, but for the purpose of the mass balance is used in
the same way) (0 < Ypaint < 1; default: Yrm)
NS (Nsites): Number of sites (integer > 0)
OD: Number of operating days (days/site-yr) (integer, 0 < OD < 365; default: 250)
Drm: Density of raw material (default; Dprod from the previous operation container
parameter or mass balance, or, if no previous value available, 1) (kg/liter)
Dfpaint: Density of formulated paint (Dfpaint replaces Dprod for user-defined
operations, but for the purpose of the mass balance is used in the same way)
(kg/liter) (default: Drm)
Vcar: Volume of coating used per car (Liters/car) (Vcar > 0; default: 8 L/car)
Near: Number of cars spray coated per site-day (Near > 0; default: 664 cars/site-day
based on 166,000 cars/site-yr and 250 days/site-yr)
DVUfpaint: Volume of formulated coating used per day (gallons/site-day) (DVUfpaint > 0)
These parameters are used to perform mass balance calculations on the ChemSTEER Operation
Parameters windows as described by the default value calculations for this industry operation listed
below. If you choose to update any default values, ChemSTEER updates other values using the logic and
379
-------
ChemSTEER User Guide - Updated May 2015
calculations described in the Operation Parameters Tab -> Mass Balance Parameters Subtab pages of
the User Guide (where the formulated paint parameters in the list above replace standard product
output parameters from that logic). Clicking the Restore defaults button will turn off the fix boxes set for
any of the parameters, clear the values for all parameters on this screen, and replace them with the
default values based on the logic and calculations listed below.
Default Calculations
Default values for the mass balance parameters for this industry operation are calculated based
upon the following logic and calculations.
1. Yfpaint = Yrm = Yprod from previous operation.
2. DMUfpaint = Vcar x Dfpaint x Near (using default values shown in parameter list above).
3. DMUchem = DMUfpaint x Yfpaint.
4. If PVop < DMUchem x OD, then NS = 1
If PVop > DMUchem x OD, then NS = PVop / (DMUchem x OD); If NS is not calculated to be an
exact integer, it will be rounded up to the next highest integer above PVop / (DMUchem x OD).
5. OD = PVop/NS/DMUchem
6. DMIchem = DMUchem
7. DMIrm = DMIchem/Yrm
A primary calculation for this operation is DMUfpaint (daily mass of formulated coating used).
You may revise DMUfpaint by checking the fix box for DMUpaint, which activates the Calculate button
next to the display box for the value of this parameter. Clicking on this Calculate button launches the
Update Mass of Formulated Paint Used window.
In this window you have the option of choosing between two methods of calculating
DMUfpaint. You have the option of retaining or updating the values of any of the parameters used by
the method that is selected. The first method uses the equation:
DMUfpaint = Vcar (liters of paint/car) x Dfprod (formulated coating density, kg/L) x Near
(number of cars/site-day).
The second method uses the equation:
DMUfpaint = VMUfpaint (gallons of formulated coating/site-day) x Dfpaint (formulated
coating density, kg/L) x 3.785 L/gal.
Clicking the Restore defaults button will clear the values for all parameters on this screen and
replace them with the default values based on the information and logic listed above.
You may retain or update the values of any of the parameters used by the method that is selected.
380
-------
ChemSTEER User Guide - Updated May 2015
Operation Parameters tab / Shared Parameters/Factors sub tab
When the Automobile OEM Spray Coating operation is selected, the Shared Parameters/Factors
subtab will display the Automotive Spray Coating shared parameter/factor, Spray Gun Type, by default.
The user may change the Spray Gun Type default value by double-clicking on it in the table. The
Automobile OEM Spray Coating default setting, as well as the non-default option is summarized for the
shared Spray Gun Type in the table below:
Conventional*
HVLP
*The conventional spray gun default for the Automobile OEM Spray Coating Operation was adopted as
an internal policy decision in July 2003.
Releases Tab
For the Automotive OEM Spray Coating Application source/activity, the default multi-media
release model is the EPA/OPPT Automobile OEM Coating Oversprav Loss Model.
Exposures Tab
For the Automotive OEM Spray Coating Application source/ activity:
• The overriding default for this worker activity: NWexp = 17 workers per site.
The default dermal exposure model is the US EPA Memo entitled Updating CEB's Method for
Screening-Level Assessments of Dermal Exposure. September 2013.
• EPA/OPPT 2-Hand Dermal Immersion with Liquid Model.
• The default inhalation exposure model is the EPA/OPPT Automobile OEM Spray Coating
Inhalation Exposure Model.
References
SAIC for US EPA/OPPT. Generic Scenario for Automobile Spray Coating Draft Report. August
1996.
381
-------
ChemSTEER User Guide - Updated May 2015
Electroplating Bath Additive Use
Revised April 14, 2004. This operation is applicable to the use of a material that is added to an
electroplating bath. Electroplating is the process by which a metal coating is applied to an object
immersed in an electrolytic solution (i.e., the bath) by passing a current through the solution (the article
to be plated is the cathode). This operation also applies to anodizing (wherein the surface to be plated is
the anode) and electroless or autocatalytic plating (wherein a chemical reducing agent is used to reduce
a dissolved metal onto a surface without the use of an electric current). This operation estimates the
releases of and worker exposure to a chemical contained in the bath additive. The August 1996 Generic
Scenario: Electroplating document was the primary reference source for the operation defaults
described below.
Operations tab -> Description subtab
Selected NAICS
The following NAICS code is pre-selected for this operation:
• 332813 - Electroplating, Plating, Polishing, Anodizing, and Coloring
Process Description
NOTE: Release sources and exposure activities prior to the charging step of this operation (e.g.,
unloading of containers, empty container cleaning/disposal) are not included and must be manually
selected.
The process begins with several pre-treatment cleaning steps including immersion and spray
rinses of the parts to be plated. These pretreatment steps typically utilize deionized water and alkaline
or acidic solutions. The parts are then dipped into the plating bath, which consists of the metal ions in
solution (as provided by dissolved metal from the anode or metal salts/oxides), complexing agents,
stabilizers to prevent hydrolysis, buffers for pH maintenance, and catalysts.
These additive chemical concentrations range from amounts measured in ppm for brighteners
up to 20 percent for metal salts. Electroplating baths are almost always aqueous-based.
The dip time and bath size depend on the metal to be plated, the thickness of the desired
coating, and the size and shape of the immersed part. After dipping, the part is then rinsed by several
more immersion and spray rinses with deionized and permeate water. The part is then baked to cure
the coating.
Although electroplating includes all of the stages mentioned above, this operation applies only
to plating followed by rinsing.
The additives are usually nonvolatile and tend to remain in the bath. The baths, however, are
equipped with exhaust systems for any vapors that may exist above the solution surface. Worker
exposure may occur during transfer of the additive from shipping containers to recharge the dip tanks.
The worker may also be exposed to additive materials during sampling or other activities wherein
evolved hydrogen and oxygen gas rising from the submerged part, the anode, or the cathode, as well as
from the residual bath solution dragged with the part into the air. Sources for potential environmental
382
-------
ChemSTEER User Guide - Updated May 2015
releases include discharge of waste rinsing materials and spent baths. There may also be releases from
container residues and potentially from the pre-treatment cleaning steps; both must be manually
assessed.
The default process description for this operation is as follows:
Pre-treatment cleaning steps (not assessed by this operation) -> Transfer of additive
containing the chemical from shipping container into dip tank (you must manually add
or adjust unloading and cleaning activities based on the loading activity in the previous
operation) -> Electroplate surfaces of parts-> Plated parts immersed in rinse tanks and
spray rinsed -> Bake/cure plated coating (chemical is either destroyed or fixed to the
coated surface)
Operations tab / Sources/Activities subtab
The following default sources/activities are automatically listed on the Sources/Activities that
will be assessed in the operation list on the Update Operation Sources/Activities screen (launched by the
Update Sources/Activities button):
• Changing Electroplating Bath (Exposure - No. Release - Yes)
• Rinsing Electroplated Parts (Exposure - No. Release - Yes)
• Operating the Electroplating Bath (Exposure - Yes. Release - No)
Available Activities
• All other activities
NOTE: The Charging Electroplating Batch, Rinsing Electroplated Parts, and Operating the
Electroplating Batch source/activities may not be used for any operation other than the Electroplating
Batch Additive Use operation.
¦ ¦ ... ¦' ' ' ¦ • • : - i,: ¦ :
Clicking the Update Parameters button on the Mass Balance Parameters subtab launches the
Update Operation Mass Balance Parameter screen. The following logic defines the default conditions
and parameter values for this screen.
Mass Balance Basis Selection tab
Default selections are Continuous and Electroplating Bath Additive Usage (where Electroplating
Bath Additive Usage replaces Product since the basis is actually the chemical additive used in the bath
solution rather than a true Product).
Specify Mass Balance Input Parameters
If you select a different basis other than the default basis selection (Continuous and
Electroplating Bath Additive Usage), ChemSTEER uses the logic and calculations (with user-defined
processing rules) described in the Entering/Updating Mass Balance Parameters pages of the User Guide.
The user must manually make all mass balance calculations by substituting the parameters for the
383
-------
ChemSTEER User Guide - Updated May 2015
amount of additive used in place of standard product output parameters from that logic, and the logic
and default calculations below for this operations are not used.
For this scenario, if the default basis selection is retained (Continuous and Electroplating Bath
Additive Usage), the Specify Mass Balance Input Parameters screen will have two non-standard text
changes.
1) The "Calculate remaining two parameters" button is re-labeled "Calculate remaining
parameters"
2) The standard mass balance instruction text at the top of the screen is changed to "Please
specify at least one (maximum three) of the first five parameters. ChemSTEER will calculate the
remaining parameters for you."
If you retain the default basis selection, the parameters listed below and the following logic are
used to perform mass balance calculations.
Parameters
DMIrm:
DMIchem:
ADMUaddtv:
ADMUchem:
Yrm:
Yaddtv:
NS:
OD:
Ybath:
Yrinse:
Dbath:
Daily mass input of raw material (kg/site-day)
Daily mass input of the chemical (kg/site-day)
Averaged daily mass of the bath additive used to replace intermittent losses
from bath changes and daily losses from rinsing parts (ADMUaddtve replaces
DMOprod for user-defined operations, but for the purpose of the mass balance
is used in the same way) (kg/site-day) (0 < ADMUaddtve) (default based on
equations presented below)
Averaged daily mass of chemical in the bath additive used to replace
intermittent losses from bath changes and daily losses from rinsing parts
(ADMUchem replaces DMOchem for user-defined operations, but for the
purpose of the mass balance is used in the same way) (kg/site-day) (0 <
ADMUchem) (Read-only, default based on equations presented below;
ADMUchem can only be updated by modifying changeable parameters on the
update ADMUchem screen.)
Weight fraction of the chemical in raw material (0 < Yrm < 1; default: Yprod
from previous operation or, if no previous operation, 1)
Weight fraction of the chemical in the additive (Yaddtve replaces Yprod for
user-defined operations, but for the purpose of the mass balance is used in the
same way) (0 < Yaddtve < 1; default: Yrm)
Number of sites (integer > 0) (default based on equations presented below)
Number of operating days (days/site-yr) (integer, 0 < OD < 365; default: 250)
Weight fraction of the chemical in the bath (0 < Ybath < 1; default: 0.0434)
Weight fraction of the chemical in the rinse water (0 < Yrinse < 1 and < Ybath;
default: 0.0235 or Ybath x 0.50, if user-defined Ybath)
Density of the bath (kg/liter) (default: 1)
384
-------
ChemSTEER User Guide - Updated May 2015
Drinse: Density of the rinse (kg/liter) (default: 1)
Vbath: Volume of solution per bath (gallons/bath) (Vbath < 0; default: 2,500)
Nbath: Number of bath tanks per site (baths/site) (default: 3)
Freqbath: Frequency of bath changes per year (changes/bath/yr) (Freqbath > 0; default: 2)
DVrinse: Daily volume of rinse water generated per site (gallons/site-day) (DVrinse > 0;
default: 4932)
RinseE: Rinsewater recovery efficiency (0 < RinseE < 1; default: 0.90)
EPVop: Estimated PVop for iterative calculation sequences.
These parameters are used to perform mass balance calculations for this industry operation on
the ChemSTEER Operation Parameters windows using the logic and calculations described below.
Clicking the Calculate button next to ADMUchem in the Specify Mass Balance Input Parameters subtab
will allow you to review or modify additional mass balance parameters for this operation by activating
the Update Average Daily Mass of Chemical Used window. Clicking the Restore defaults button in the
Update Average Daily Mass of Chemical Used window will turn off the fix boxes set for any of the
parameters except Yrinse (which remains checked), clear the values for all parameters on this screen,
and replace them with the default values shown above and based on the logic and calculations
described below.
Default values for the mass balance parameters for this industry operation are calculated based
upon the following logic and calculations, where Vbath, Nbath, Freqbath, Dbath, Ybath, OD, DVrinse,
Drinse, Yrinse (fix box checked by default on the Update Average Daily Mass of Chemical Used window),
and RinseE are initially set to the default values given in the parameter list above.
EP1. ADMUchem = [(Vbath x Nbath x Freqbath x Dbath x 3.78 L/gal x Ybath / OD) + (DVrinse x
Drinse x 3.78 L/gal x Yrinse x (1 - RinseE))]
EP2. NS= PVop/ OD/ ADMUchem
If NS is not calculated to be an exact integer, NS is rounded up to the next highest
integer above PVop / OD / ADMUchem. If NS is calculated to be less than 1, it is rounded
up to 1 site and OD is recalculated using EP2a (note that EP2a can also be used to
resolve mass balance discrepancies in cases where ADMUchem is directly fixed or set by
the selection of Yaddtv and ADMUaddtv fix boxes):
EP2a. OD = PVop/ NS/ ADMUchem
EP3. ADMUchem = PVop / NS / OD (resolves discrepancies due to rounding of NS)
Note: The read-only value of ADMUchem is only re-adjusted if it is not fixed (i.e., the
read-only of ADMUchem will be set by the fix box; however, non-user specified values
of changeable parameters used to calculate ADMUchem can be adjusted based on the
sequences described below - with the value of ADMUchem unchanged).
EP4. Yaddtv = Yrm = Yprod from previous operation (or 1 if no previous operation)
EP5. ADMUaddtv = ADMUchem /Yaddtv
EP6. DMIchem = ADMUchem
385
-------
ChemSTEER User Guide - Updated May 2015
EP7. DMIrm = DMIchem / Yrm
Because ADMUchem and OD are related both by the primary equation EP1 for electroplating and by
the standard mass balance equation EP3, ChemSTEER recalculates parameters in EP1 to maintain the
mass balance after each recalculation of ADMUchem from equations other than EP1. These
recalculations depend upon fix box conditions and are shown in Sequences A, B, C, and D below. To
complete the calculation of default values, ChemSTEER uses Sequence A.
Mass Balance Maintenance Sequences A, B, C, and D
Sequence A - Both Vbath and DVrinse fix boxes are NOT checked.
ChemSTEER solves for Vbath and DVrinse with the assumption DVrinse = Vbath x Nbath x 4932 /
7500 (ratio of default values in the reference document):
Vbath =ADMUchem / [(Nbath x Freqbath x Dbath x 3.78 x Ybath / OD) +
(4932 / 7500 x Nbath x Drinse x 3.78 x Yrinse x (1-RinseE))]
DVrinse =(4932 / 7500) x Nbath x Vbath
Sequence B - Vbath fix box is checked and DVrinse fix box is NOT checked.
ChemSTEER solves for DVrinse:
DVrinse =[ADMUchem - (Vbath x Nbath x Freqbath x Dbath x 3.78 L/gal x Ybath / OD)] /
(Drinse x 3.78 L/gal x Yrinse x (1 - RinseE))
If DVrinse < 0, then DVrinse = 0. A pop-up warning window with the message "Parameters
should be adjusted such that ADMUchem is increased and/or Vbath is decreased" appears and clicking
OK removes the window. This message appears both at the bottom of the Update Average Daily Mass of
Chemical Used window and at the bottom of the Specify Mass Balance Input Parameters subtab.
Sequence C - Vbath fix box is NOT checked and DVrinse fix box is checked.
ChemSTEER solves for Vbath:
Vbath =[ADMUchem - (DVrinse x Drinse x 3.78 L/gal x Yrinse x (1 - RinseE))] /
(Nbath x Freqbath x Dbath x 3.78 L/gal x Ybath / OD)
If Vbath < 0, then Vbath = 0. A pop-up warning window with the message "Parameters should be
adjusted such that ADMUchem is increased and/or DVrinse is decreased" appears and clicking OK
removes the window. This message appears both at the bottom of the Update Average Daily Mass of
Chemical Used window and at the bottom of the Specify Mass Balance Input Parameters subtab.
Sequence D - Both Vbath and DVrinse fix boxes ARE checked.
386
-------
ChemSTEER User Guide - Updated May 2015
ChemSTEER checks for mass balance discrepancies:
If the absolute value of
[ADMUchem - ((Vbath x Nbath x Freqbath x Dbath x 3.78 L/gal x Ybath / OD) + (DVrinse x Drinse
x 3.78 L/gal x Yrinse x (1 - RinseE))) / ADMUchem]
is greater than 0.05, a pop-up warning window with the message "The fixed values of DVrinse
and Vbath result in a mass balance discrepancy of greater than 5%" appears and clicking OK removes the
window. This message appears both at the bottom of the Update Average Daily Mass of Chemical Used
window and at the bottom of the Specify Mass Balance Input Parameters subtab.
Upon completion of Sequence A, B, C, or D, ChemSTEER recalculates equations EP4 through EP7
(unless the fix box is checked for any of these parameters, which causes that value to remain fixed), the
mass balance update is completed, and the updated parameter values are displayed. If no warning
message was displayed based on Sequence A, B, C, or D, ChemSTEER checks for any mass balance
discrepancy as described in the Entering/ Updating Mass Balance Parameters, Type of Operation:
Continuous; Basis: Product section of the User Guide and displays the result at the bottom of the Specify
Mass Balance Input Parameters subtab.
Calculation of a Non-default ADMUchem
A primary calculation for this operation is ADMUchem. The user has several options for
calculating a non-default ADMUchem. These options are defined by the following conditions.
Note: You must follow the prescribed procedures to properly recalculate ADMUchem and other
related parameters.
You should first check the fix boxes of any known parameters (up to three of the first five) and
enter the known value(s) on the Specify Mass Balance Input Parameters subtab. If desired, you should
then click the Calculate button next to the display box for the value of ADMUchem, which launches the
Update Average Daily Mass of Chemical Used window.
In this window you have the option of retaining or updating the values of any of the parameters
used in the equation shown. You may also check fix boxes for some parameters to set known values.
Unchecked parameters may be adjusted by the previously described sequences.
After making appropriate updates, you may click the Update Mass Balance button, which
launches the Electroplating Mass Balance Update Logic and Calculations listed below. Alternatively, if
you click the Restore Defaults button, the ChemSTEER default values for all changeable parameters in
Update Average Daily Mass of Chemical Used window appear.
If you click the OK button, the Update Average Daily Mass of Chemical Used window closes and
ChemSTEER retains the values and fix box conditions last shown in the window. If you click the Cancel
button, the Update Average Daily Mass of Chemical Used window closes and ChemSTEER retains the
values and fix box conditions that first appeared in the window when it was launched.
387
-------
ChemSTEER User Guide - Updated May 2015
At any time, clicking the Calculate remaining parameters button on the Specify Mass Balance
Input Parameters subtab launches the Electroplating Mass Balance Update Logic and Calculations listed
below.
Electroplating Mass Balance Update Logic and Calculations
If the fix box for Yrinse is not checked, Yrinse = 0.5 x Ybath. If Yrinse is fixed and Ybath is
changed, an error message will appear: "Would you like to update Yrinse to the default, Yrinse = 0.5 x
Ybath." Selecting Yes updates Yrinse and clears the Yrinse fix box.
ChemSTEER determines which of the following three conditions is true and proceeds to use the
logic and calculations appropriate to the condition which is true.
Condition 1. ADMUchem is fixed or can be calculated by the standard mass balance logic (NS
and OD or ADMUaddtv and Yaddtv are both fixed)
ADMUchem and the other associated parameters are fixed or calculated based on the
relationships in equations EP2 and/ or EP5, as appropriate, completes any associated calculations that
are possible using standard mass balance logic and calculations, and then launches the appropriate
Sequence A, B, C, or D. These calculations complete the mass balance update.
Note: if OD is not fixed or is not calculable with standard mass balance equations (NS and
ADMUchem are not fixed), 250 days per year will be assumed when calculating equation EP-2.
Condition 2. NS is fixed and neither OD nor ADMUchem are fixed (nor can ADMUchem be
calculated by the standard mass balance logic (Yaddtv and ADMUaddtv cannot both be fixed for this
condition))
ChemSTEER calculates OD and ADMUchem using the following iterative approach.
C2-1. OD = 1
C2-2. ADMUchem is calculated using eqn. EP1
C2-3. EPVop = ADMUchem xNSxOD
C2-4. If EPVop < PVop and OD < 365 increase OD by one and repeat C2-2 and C2-3
C2-5. ADMUchem = PV/ NS/OD
C2-6. Launch the appropriate Sequence A, B, C, or D
Condition 3. NS is not fixed and ADMUchem is not fixed and cannot be calculated by the
standard mass balance logic (Yaddtv and ADMUaddtv cannot both be fixed for this condition)
ChemSTEER calculates ADMUchem and NS based on the value of OD.
C3-1 ADMUchem is calculated using equation EP1
C3-2 NS is calculated using eqn. EP2
388
-------
ChemSTEER User Guide - Updated May 2015
If NS is not calculated to be an exact integer, NS is set to the next highest integer. If NS had been
calculated to be less than 1 (and then rounded up to 1 site) AND OD is NOT fixed, then OD is
recalculated using EP2a.
C3-3 ADMUchem = PV/NS/OD
C3-4. Launch the appropriate Sequence A, B, C, or D
Fix Box(es) Selected
Condition
Equation Notes/ Sequence (if non-standard)
No fix boxes selected
Initial Default
Condition
Condition 2
Assume OD = 250, EP1, EP2, EP2a if NS was < 1, EP3, EP4, EP5,
EP6, EP7
EP4, EP5, EP6, EP7
NS
NS and OD
Condition 1
EP3, EP4, EP5, EP6, EP7
NS and Yaddtv
Condition 2
EP5, EP6, EP7
NS and ADMUaddtv
Condition 2
EP5 (for Yaddtv), EP4 (forYrm), EP6, EP7
NS and ADMUchem
Condition 1
EP2a, EP4, EP5, EP6, EP7
OD
Condition 3
EP4, EP5, EP6, EP7
OD and Yaddtv
Condition 3
EP5, EP4 (forYrm), EP6, EP7
OD and ADMUaddtv
Condition 3
EP5 (forYaddtv), EP4 (forYrm), EP6, EP7
OD and ADMUchem
Condition 1
EP2, EP4, EP5, EP6, EP7
Yaddtv
Condition 3
Assume OD = 250 dpy, EP4 (for Yrm), EP6, EP7
Yaddtv and ADMUaddtv
Condition 1
EP5 (for ADMUchem), assume OD = 250 dpy, EP2, EP2a, EP3,
EP4 (forYrm), EP6, EP7
Yaddtv and ADMUchem
Condition 1
Assume OD = 250 dpy, EP2, EP2a, EP5, EP4 (for Yrm), EP6, EP7
ADMUaddtv
Condition 3
Assume OD = 250 dpy, EP5 (for Yaddtv), EP4 (for Yrm), EP6, EP7
ADMUaddtv and ADMUchem
Condition 1
Assume OD = 250, EP2, EP2a, EP5 (forYaddtv), EP4 (forYrm),
EP6, EP7
ADMUchem fixed only
Condition 1
Assume OD = 250, EP2, EP2a, EP4, EP5, EP6, EP7
NS, OD, and Yaddtv
Condition 1
EP3, EP5, EP4 (forYrm), EP6, EP7
NS, OD, and ADMUaddtv
Condition 1
EP3, EP5 (forYaddtv), EP4 (forYrm), EP6, EP7
Yaddtv, ADMUaddtv, and NS
Condition 1
EP5 (for ADMUchem), EP2a, EP3, EP4 (forYrm), EP6, EP7
Yaddtv, ADMUaddtv, and OD
Condition 1
EP5 (for ADMUchem), EP2, EP3, EP4 (forYrm), EP6, EP7
ADMUchem, NS, and Yaddtv
Condition 1
EP2a, EP5, EP4 (forYrm), EP6, EP7
ADMUchem, NS, and
ADMUaddtv
Condition 1
EP2a, EP5 (forYaddtv), EP4 (forYrm), EP6, EP7
ADMUchem, OD, and Yaddtv
Condition 1
EP2, EP5, EP4 (forYrm), EP6, EP7
ADMUchem, OD, and
ADMUaddtv
Condition 1
EP2, EP5 (forYaddtv), EP4 (forYrm), EP6, EP7
Operation P. .• • Shared Param •' 1 • 3
389
-------
ChemSTEER User Guide - Updated May 2015
When the Use of Electroplating Bath Additives operation is selected, the Shared
Parameters/Factors subtab will display the Electroplating shared parameter/factor, "Electroplating
Additive Type", by default. The user may change the Electroplating Additive Type default value by
double-clicking on it in the table. The Electroplating default setting, as well as the available non-default
option is summarized for the shared Electroplating Additive Type in the table below:
Shared Parameter/Factor
Default Value/Setting
Non-default Option
Electroplating Additive Type*
Organic Compounds
Suspended Solids
* This parameter is shared by the EPA/OPPT Electroplating Rinse Water Loss Model and the EPA/OPPT
Electroplating Spent Bath Disposal Model.
Releases tab
For the Changing Electroplating Bath source/activity, the default model is:
• EPA/OPPT Electroplating Rinse Water Loss Model
For the Rinsing Electroplated Parts source/activity, the default model is:
• EPA/OPPT Electroplating Spent Bath Disposal Model
Exposures tab
For the Operating Electroplating Bath source/activity:
• The overriding default for this worker activity: NWexp = 20 workers per site (Operating
Electroplating Bath is the only default exposure activity).
• There is no default dermal exposure model.
• The default inhalation exposure model is the OSHA PEL-Limiting Model for Substance-
specific Particulates (TWA or C).
As a default, the Electroplating generic scenario uses the OSHA PEL for chromium to calculate
worker exposures. Therefore, the overriding default for KCk = 0.5 mg/m3 (chromium OSHA PEL) and
Ypel = 0.25 (estimated chromium bath weight fraction). You may find additional OSHA values by clicking
the View Exposure Limits button on the Chemical tab. Typical concentrations for various metal plating
baths can be viewed in Chart B of the August 1996 Generic Scenario: Electroplating document.
References
SAICfor US EPA/OPPT. Generic Scenario: Electroplating. August 1996.
390
-------
ChemSTEER User Guide - Updated May 2015
Recirculating Water-Cooling Tower Additive Use
Revised March 30, 2004. This operation is applicable to the use of water treatment additives
(e.g., as a scale, corrosion, or microorganism inhibitor) for recirculating cooling systems. The additives
are transferred into the recirculating water to maintain a specified concentration. This operation
estimates releases of the additive chemical as a result of the routine functions of the water-cooling
system. The Summary Sheet: Recirculating Water-Cooling Tower (no date), was the primary reference
source for the operation defaults described below.
It should be noted that the default usage rate for the additive is based upon the estimated daily
releases of the additive. The daily releases are effectively calculated in the Mass Balance portion of the
Operation Parameters tab instead of in the Releases tab. The release models for this operation use the
values entered/calculated in the Operation Parameters tab.
Operations tab -> Description subtab
Selected NAICS
There is no default NAICS code for this operation. Recirculating water-cooling towers are a
general unit operation that may be found within virtually any industry sector. Therefore, the user must
manually select an industry sector(s) relevant to their assessment.
Process Description
NOTE: Release sources and exposure activities prior to the metering step of this operation (e.g.,
unloading of containers, empty container cleaning/disposal) are not included and must be manually
selected. ChemSTEER's mass balance functions are not fully optimized to ensure an automatic balancing
of chemical input to and output/release from an operation. For example, ChemSTEER does not currently
account for pre-process releases of the chemical (e.g., as a result of amounts of the chemical remaining
in transport containers). In operations where all of the chemical used is anticipated to be released (e.g.,
as in the Recirculating Water-Cooling Tower Additive Use operation), these pre-process releases will
result in more of the chemical being released than is input to the operation. Future versions of
ChemSTEER will include additional functions to correct for these pre-process releases.
The recirculating cooling tower additive containing the chemical being assessed is shipped to the
sites in containers. Depending upon the facility's practice and the size of the shipping container, the
additive may be unloaded into a storage tank until use or stored in the original container.
The additive is transferred into the recirculating water within the cooling tower at a specified
rate, such that the desired concentration of the additive within the water is maintained. Losses of the
additive primarily occur as a result of "blowdown" and "windage". Blowdown occurs when the facility
must discard amounts of the water to adjust the concentrations of nonvolatile components (e.g., salts).
Windage losses are a function of the equipment's mist eliminator design. If the additive is relatively
volatile, evaporative losses to the air may also occur.
The default process description for this operation is as follows:
391
-------
ChemSTEER User Guide - Updated May 2015
Unload water cooling-tower additive containing the assessed chemical from shipping
container -> Store (optional) -> Mix into the cooling tower recirculating water to
maintain a specific concentration (losses to blowdown and windage, and if the additive
is volatile, to evaporation).
Operations tab / Sources/Activities subtab
The following default source/activity is automatically listed on the Sources/Activities that will be
assessed in the operation list on the Update Operation Sources/Activities screen (launched by the
Update Sources/Activities button):
• Recirculating Water-Cooling Tower Additive Releases (Exposure - No. Release - Yes)
Available Activities
• All other activities
NOTE: The Recirculating Water-Cooling Tower Additive Releases source/activity may not be used for
any operation other than the Recirculating Water-Cooling Tower Additive Use operation.
0 ¦ • ¦ ¦ . • . : .' . : )
Clicking the Update Parameters button on the Mass Balance Parameters subtab launches the
Update Operation Mass Balance Parameter screen. The following logic defines the default conditions
and parameter values for this screen.
Mass Balance Basis Selection tab
Default selections are Continuous and Cooling Tower Additive Usage (where Cooling Tower
Additive Usage replaces Product since the basis is actually the additive used rather than a true product).
The user cannot change these selections for this operation.
Specify Mass Balance Input Parameters
ChemSTEER uses the parameters listed below and the following logic are used to perform mass
balance calculations.
Parameters
NOTE: The equivalent parameter designation in the Summary Sheet: Recirculating Water-
Cooling Tower, if applicable, appears in parentheses.
DMIrm: Daily mass input of raw material containing the assessed additive chemical
(kg/site-day) (default: DMUaddtv)
DMIchem: Daily mass input of the chemical in the raw material (assumed to be equal to the
amount used) (kg/site-day) (default: DMUchem)
DMUaddtv: Daily mass use of additive containing the assessed chemical (DMUaddtv
replaces DMOprod for user-defined operations, but for the purpose of the mass
balance is used in the same way) (kg/site-day) (default: DMUchem / Yaddtv)
392
-------
ChemSTEER User Guide - Updated May 2015
DMUchem: Daily mass of chemical in the additive used (DMUchem replaces DMOchem for
user-defined operations, but for the purpose of the mass balance is used in the
same way) (kg/site-day) (default: based on equations presented below)
Yrm: Weight fraction of the chemical in raw material (0 < Yrm < 1; default: Yprod
from previous operation or, if no previous value available, 1)
Yaddtv: Weight fraction of the chemical in the additive (Yaddtv replaces Yprod for user-
defined operations, but for the purpose of the mass balance is used in the same
way) (0 < Yaddtv < 1; default: Yrm)
NS: Number of sites (integer > 0) (default based on equations presented below)
OD: Number of operating days (days/site-yr) (integer, 0 < OD < 365; default: 360)
Yctw (xR): Weight fraction of the chemical in the cooling tower water (0 < Yctw < 1;
default: 0.001)
Dctw: Density of the recirculating cooling tower water (kg/gal) (0 < Dctw; default:
3.785 (equivalent to the density of water))
RRctw: Recirculation rate of the cooling tower water (gallons/min) (0 < RRctw; default:
2,000)
HD: Hours per day of cooling tower operation (hrs/site-day) (0 < HD < 24; default:
24)
DRRchem: Daily recirculation rate of chemical in the cooling tower (kg/site-day) (0 <
DRRchem) (default: based on equation presented below)
LFb: Loss fraction of daily recirculation rate (DRRchem) for cooling tower blowdown
(0 < LFb < 1; default: 0.006)
LFw: Loss fraction of daily recirculation rate (DRRchem) for cooling tower windage (0
< LFw < 1; default: 0.001)
LFe: Loss fraction of daily recirculation rate (DRRchem) from cooling tower
evaporation (0 < LFe < 1; default: 0)
NOTE: The reference states that evaporative losses range from 0.5% to 3% of the recirculation
rate. ChemSTEER defaults to 0 regardless of volatility. There is no method for determining the
relationship between volatility and evaporative loss. If the assessed chemical has significant volatility,
the user should make a judgment as to whether a non-zero value of LFe is appropriate.
These parameters are used to perform mass balance calculations on the ChemSTEER Operation
Parameters windows as described by the default value calculations for this industry operation listed
below. If the user chooses to update any default values, ChemSTEER updates other values using the logic
and calculations described in the Operation Parameters Tab -> Mass Balance Parameters Subtab pages
of the User Guide. Clicking the Restore defaults button will turn off the fix boxes set for any of the
parameters, clear the values for all parameters on this screen, and replace them with the default values
based on the logic and calculations listed below.
Default Calculations
Default values for the mass balance parameters for this industry operation are calculated based
upon the following logic and calculations.
1. DMUchem = (LFb + LFw + LFe) x DRRchem (see equation for DRRchem described below
for the Daily Mass of Chemical calculations)
2. Yaddtv = Yrm = Yprod from the previous operation (or 1 if no previous operation)
393
-------
ChemSTEER User Guide - Updated May 2015
3. DMUaddtv = DMUchem / Yaddtv
4. If PVop < DMUchem x OD, then NS = 1
If PVop > DMUchem x OD, then NS = PVop / (DMUchem x OD); if NS is not calculated to be an
exact integer, it will be rounded up to the next highest integer above PVop / (DMUchem x OD).
5. OD (recalculated) = PVop / NS / DMUchem
6. DMIchem = DMUchem
7. DMIrm = DMIchem/Yrm
Other Parameter Calculations
A primary calculation for this operation is DMUchem (daily mass of chemical used). You may
revise DMUchem by checking the fix box for DMUchem, which activates the Calculate button next to the
display box for the value of this parameter. Clicking on this Calculate button launches the Calculate
DMUchem: Daily Mass of Chemical Used (kg/site-day) window.
In this window, you have the option of choosing between two methods of calculating
DMUchem. You may retain or update the values of any of the parameters used by the method that is
selected. The first method, which is the ChemSTEER default, uses the equations:
DRRchem = RRctw (recirculation rate of cooling tower water, gal/min) x Yctw (fraction of
the chemical in the cooling tower water) x HD (operating hrs/day) x Dctw
(density of the cooling tower water, kg/gal) x 60 min/hr
DMUchem = (LFb + LFw + LFe) (sum of loss fractions for blowdown, windage, and
evaporation) x DRRchem (daily recirculation rate of the chemical in the cooling
tower, kg/site-day)
Each of the parameters used in the equations contain the default values shown in the parameter
list above. You may change any values of the four parameters in the DRRchem equation and any of the
three LF values and click the Recalculate button to recalculate values of DRRchem and DMUchem.
The second method allows you to fix DMUchem by checking the fix box next to the parameter.
You may then change DMUchem and any of the three LF values and click the Recalculate button to
recalculate value of DRRchem, which is recalculated using the following equation:
DRRchem = DMUchem (daily mass of chemical in the additive used, kg/site-day) / (LFb +
LFw + LFe) (sum of loss fractions for blowdown, windage, and evaporation).
Clicking the Restore defaults button will clear the values for all parameters on these screens and
replace them with the default values based on the information and logic listed above. Clicking Cancel
will exit this window and retain the original value of DMUchem shown in the Specify Mass Balance Input
Parameters screen. Clicking OK will exit this window and update the value of DMUchem in the Specify
Mass Balance Input Parameters screen.
394
-------
ChemSTEER User Guide - Updated May 2015
You may NOT directly enter a value for DMUchem in the Specify Mass Balance Input Parameters
screen.
Changes to the value of DMUchem (via calculation in Method 1 or direct entry in Method 2 above)
may cause the Number of Sites (NS) in the Specify Mass Balance Input Parameters screen to be
recalculated (via Equation #4, above). If NS is fixed, ChemSTEER retains that value as a user-specified
(fixed value) and re-calculates Operating Days (OD) (via Equation #5, above). Sometimes, the
recalculated OD is an unrealistically low number or is greater than 365 (a warning message will appear
that you will need to resolve).
If you receive this message and would like to update NS based on changes to DMUchem, click the
Re-calculate NS button on the Update DMUchem screen. ChemSTEER temporarily sets OD = 360, re-
calculates NS based on the new DMUchem and Equation #4 above, and then re-calculates OD based on
the new NS using Equation #5. The Re-calculate NS button is only active when NS is fixed in the Specify
Mass Balance Input Parameters screen.
Alternative Parameter Values
The reference document contains several alternative parameter values and ranges for some
parameters. If one or more alternative values apply to a particular assessment, you may consider
changing the default values. These alternative values and ranges are summarized below.
Yctw should be selected based on the function of the additive within the cooling tower. The
following table summarizes the default Yctw values in the reference document:
Function of the Cooling Tower Additive
Range in Concentration As
Used(ppm)
Default Yctw (dimensionless)
Corrosion Control (default function)
50 to 1,000
0.001
Microorganism Control
1 to 20
0.00002
Scale Control
1 to 5
0.000005
The following table summarizes the default LF values in the reference document.
Source of the Release (Loss Fraction
Designation
Range of Loss Fractions
Default LF (dimensionless)
Blowdown (LFb)
0.005 to 0.006
0.006
Windage (LFw)
0.00008 to 0.002
0.001
Evaporation (LFe)
0.005 to 3*
Q**
* Applicable to chemicals with volatility.
** Applicable to non-volatile chemicals.
Finally, the reference document notes that large cooling towers have water recirculation rates
(RRctw) of up to 100,000 gpm, and this value may be used to estimate conservative release estimates.
The reference document indicates that a 2,000 gpm tower is a moderately-sized tower.
395
-------
ChemSTEER User Guide - Updated May 2015
Operation Parameters tab 1 ared Parameters/Factors Subtab
When the Recirculating Water-Cooling Tower Additive operation is selected, the Shared
Parameters/Factors subtab will display the Recirculating Water-Cooling Tower Additive shared
parameter/factor, the amount of chemical to which a loss fraction is applied (Amt), by default. The Amt
parameter is used by the three default release models of the default source/activity for this operation.
The default value for Amt is the value of DRRchem from the Mass Balance Parameters subtab. To
change the value of Amt, you must recalculate DRRchem in the Mass Balance Parameters subtab by
clicking the Calculate button next to the display box for the value of DMUchem. Clicking on this Calculate
button launches the Daily Mass of Chemical Used (DMUchem) window, where DRRchem may be
changed. You may NOT change the default value of Amt in the Shared Parameters/Factors subtab.
Releases tab
For the Recirculating Water-Cooling Tower Additive Releases source/activity, the following
default models are pre-selected:
• EPA/OPPT Cooling Tower Slowdown Loss Model
• EPA/OPPT Cooling Tower Windage Loss Model
• EPA/OPPT Cooling Tower Evaporative Loss Model (volatiles) (activated only when
AVPlow < VPchem)
Exposures tab
There are no default exposure models for the Recirculating Water-Cooling Tower Additive
Releases source/activity.
References
Summary Sheet: Recirculating Water-Cooling Tower. No date.
396
------- |