EPA Document# EPA 740-R1-7006
June 2017
United States Office of Chemical Safety and
LhI M ^ Environmental Protection Agency Pollution Prevention
Scope of the Risk Evaluation for
Methylene Chloride
(Dichloromethane, DCM)
CASRN: 75-09-2
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June 2017
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TABLE OF CONTENTS
ACKNOWLEDGEMENTS 5
ABBREVIATIONS 6
EXECUTIVE SUMMARY 9
1 INTRODUCTION 12
1.1 Regulatory History 14
1.2 Assessment History 15
1.3 Data and Information Collection 16
2 SCOPE OF THE EVALUATION 18
2.1 Physical and Chemical Properties 18
2.2 Conditions of Use 19
2.2.1 Data and Information Sources 19
2.2.2 Identification of Conditions of Use 19
2.3 Exposures 30
2.3.1 Fate and Transport 30
2.3.2 Releases to the Environment 31
2.3.3 Presence in the Environment and Biota 32
2.3.4 Environmental Exposures 33
2.3.5 Human Exposures 33
2.3.5.1 Occupational Exposures 33
2.3.5.2 Consumer Exposures 35
2.3.5.3 General Population Exposures 35
2.3.5.4 Potentially Exposed or Susceptible Subpopulations 36
2.4 Hazards (Effects) 37
2.4.1 Environmental Hazards 37
2.4.2 Human Health Hazards 38
2.4.2.1 Non-Cancer Hazards 38
2.4.2.2 Genotoxicity and Cancer Hazards 39
2.4.2.3 Potentially Exposed or Susceptible Subpopulations 39
2.5 Initial Conceptual Models 40
2.5.1 Initial Conceptual Model for Industrial and Commercial Activities and Uses: Potential
Exposures and Hazards 40
2.5.2 Initial Conceptual Model for Consumer Activities and Uses: Potential Exposures and
Hazards 42
2.5.3 Initial Conceptual Model for Environmental Releases and Wastes: Potential Exposures and
Hazards 44
2.6 Initial Analysis Plan 46
2.6.1 Exposure 46
2.6.1.1 Environmental Releases 46
2.6.1.2 Environmental Fate 46
2.6.1.3 Environmental Exposures 47
2.6.1.4 Occupational Exposures 47
2.6.1.5 Consumer Exposures 47
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2.6.1.6 General Population 48
2.6.2 Hazards (Effects) 48
2.6.2.1 Environmental Hazards 48
2.6.2.2 Human Health Hazards 49
2.6.3 Risk Characterization 49
REFERENCES 50
APPENDICES 54
Appendix A REGULATORY HISTORY 54
A.l Federal Laws and Regulations[[[ 54
A.2 State Laws and Regulations.......................................... 62
A3 International Laws and Regulations....... 63
Appendix B PROCESS, RELEASE AND OCCUPATIONAL EXPOSURE INFORMATION 66
B.l Process Information ............... ........................................... 66
B.l.l Manufacturing (Includes Import) 66
B.l.1.1 Domestic Manufacturing 66
B.l.1.2 Import 66
B.l.2 Processing and Distribution 67
B.l.2.1 Processing as Reactant 67
B.l.2.2 Incorporated into Formulation, Mixture, or Reaction Product 67
B.l.2.3 Repackaging 67
B.l.2.4 Recycling 67
B.l.3 Uses 68
B.l.3.1 Solvents for Cleaning or Degreasing 68
B.l.3.2 Adhesives and Sealants 69
B.l.3.3 Paints and Coatings 69
B.l.3.4 Laundry and Dishwashing Products 70
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LIST OF TABLES
Table 1-1. Assessment History of Methylene Chloride 15
Table 2-1. Physical and Chemical Properties of Methylene Chloride 18
Table 2-2. Production Volume of Methylene Chloride in CDR Reporting Period (2012 to 2015) 20
Table 2-3. Categories and Subcategories of Conditions of Use for Methylene Chloride 23
Table 2-4. Environmental Fate Characteristics of Methylene Chloride 30
Table 2-5. Summary of Methylene Chloride TRI Production-Related Waste Managed in 2015 (lbs) 31
Table 2-6. Summary of Methylene Chloride TRI Releases to the Environment in 2015 (lbs) 32
LIST OF FIGURES
Figure 2-1. Initial Methylene Chloride Life Cycle Diagram 21
Figure 2-2. Initial Methylene Chloride Conceptual Model for Industrial and Commercial Activities and
Uses: Potential Exposures and Hazards 41
Figure 2-3. Initial Methylene Chloride Conceptual Model for Consumer Activities and Uses: Potential
Exposures and Hazards 43
Figure 2-4. Initial Methylene Chloride Conceptual Model for Environmental Releases and Wastes:
Potential Exposures and Hazards 45
LIST OF APPENDIX TABLES
Table_Apx A-l. Federal Laws and Regulations 54
Table_Apx A-2. State Laws and Regulations 62
Table_Apx A-3. Regulatory Actions by Other Governments and Tribes 63
Table_Apx B-l. Summary of Industry Sectors with Methylene Chloride Personal Monitoring Air Samples
Obtained from OSHA Inspections Conducted Between 2011 and 2016 71
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ACKNOWLEDGEMENTS
This report was developed by the United States Environmental Protection Agency (U.S. EPA), Office of
Chemical Safety and Pollution Prevention (OCSPP), Office of Pollution Prevention and Toxics (OPPT).
Acknowledgements
The OPPT Assessment Team gratefully acknowledges participation or input from EPA's Office of
General Counsel, Office of Research and Development and assistance from EPA contractors CSRA LLC
(Contract No. CIO-SP3, HHSN316201200013W), ERG (Contract No. EP-W-12-006), ICF (Contract No.
EP-C-14-001) and SRC (Contract No. EP-W-12-003).
Docket
Supporting information can be found in public docket: IE PA-HQ-Oil" F 1" uli- mT.
Disclaimer
Reference herein to any specific commercial products, process or service by trade name, trademark,
manufacturer or otherwise does not constitute or imply its endorsement, recommendation or favoring
by the United States Government.
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ABBREVIATIONS
°c
Degrees Celsius
ACGIH
American Conference of Government Industrial Hygienists
AEGL
Acute Exposure Guideline Level
atm
Atmosphere(s)
ATSDR
Agency for Toxic Substances and Disease Registry
BAF
Bioaccumulation Factor
BCF
Bioconcentration Factor
CAA
Clean Air Act
CASRN
Chemical Abstracts Service Registry Number
CBI
Confidential Business Information
CDR
Chemical Data Reporting
CEHD
Chemical Exposure Health Data
CEPA
Canadian List of Toxic Substances
CERCLA
Comprehensive Environmental Response, Compensation and Liability Act
CHIRP
Chemical Risk Information Platform
cm3
Cubic Centimeter(s)
CNS
Central Nervous System
COC
Concentration of Concern
CoCAP
Cooperative Chemicals Assessment Program
COHb
Carboxyhemoglobin
CPSA
Consumer Product Safety Act
CPSC
Consumer Product Safety Commission
CSCL
Chemical Substances Control Law
CWA
Clean Water Act
DCM
Dichloromethane (Methylene Chloride)
DMR
Discharge Monitoring Report
DOT
Department of Transportation
ECHA
European Chemicals Agency
EG
Effluent Guidelines
EHC
Environmental Health Criteria
EPA
Environmental Protection Agency
EPCRA
Emergency Planning and Community Right-to-Know Act
ESD
Emission Scenario Document
EU
European Union
FDA
Food and Drug Administration
FFDCA
Federal Food, Drug, and Cosmetic Act
FSHA
Federal Hazardous Substance Act
g
Gram(s)
GACT
Generally Available Control Technology
HAP
Hazardous Air Pollutant
HFC
Hyd rofluorocarbon
HHE
Health Hazard Evaluation
HMTA
Hazardous Materials Transportation Act
HPV
High Production Volume
IARC
International Agency for Research on Cancer
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ICIS-NPDES Integrated Compliance Information System for the National Pollutant Discharge
Elimination System
IDLH Immediately Dangerous to Life and Health
IMAP Inventory Multi-Tiered Assessment and Prioritisation
IRIS Integrated Risk Information System
ISHA Industrial Safety and Health Act
L Liter(s)
lb Pound
Log Koc Logarithmic Organic Carbon:Water Partition Coefficient
Log Kow Logarithmic Octanol: Water Partition Coefficient
m3 Cubic Meter(s)
MACT Maximum Achievable Control Technology
MCL Maximum Contaminant Level
MCLG Maximum Contaminant Level Goal
mg Milligram(s)
mmHg Millimeter(s) of Mercury
MOA Mode of Action
mPa-s Millipascal(s)-Second
NAC National Advisory Committee
NAICS North American Industry Classification System
NAWQA National Water Quality Assessment Program
NEI National Emissions Inventory
NESHAP National Emission Standards for Hazardous Air Pollutants
NHANES National Health and Nutrition Examination Survey
NICNAS National Industrial Chemicals Notification and Assessment Scheme
NIH National Institutes of Health
NIOSH National Institute of Occupational Safety and Health
NITE National Institute of Technology and Evaluation
NOAA National Oceanic and Atmospheric Administration
NPDWR National Primary Drinking Water Regulation
NRC National Research Council
NTP National Toxicology Program
OCSPP Office of Chemical Safety and Pollution Prevention
OECD Organisation for Economic Co-operation and Development
OEHHA Office of Environmental Health Hazard Assessment
OEL Occupational Exposure Limits
OGC Office of General Counsel
OPPT Office of Pollution Prevention and Toxics
ORD Office of Research and Development
OSHA Occupational Safety and Health Administration
OTVD Open-Top Vapor Degreaser
OW Office of Water
PEL Permissible Exposure Limit
PHMSA Pipeline and Hazardous Materials Safety Administration
POD Point of Departure
POTW Publicly Owned Treatment Works
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ppb
Part(s) per Billion
PPm
Part(s) per Million
PWS
Public Water System
QC
Quality Control
RCRA
Resource Conservation and Recovery Act
REACH
Registration, Evaluation, Authorisation and Restriction of Chemicals
REL
Recommended Exposure Limit
RICE
Reciprocating Internal Combustion Engines
SDWA
Safe Drinking Water Act
SIAP
SIDS Initial Assessment Profile
SIDS
Screening Information Data Set
SMAC
Spacecraft Maximum Allowable Concentrations
SNAP
Significant New Alternatives Policy
STEL
Short-Term Exposure Limit
STORET
STOrage and RETrieval and Water Quality exchange
TCCR
Transparent, clear, consistent, and reasonable
TLV
Threshold Limit Value
TRI
Toxics Release Inventory
TSCA
Toxic Substances Control Act
TTO
Total Toxic Organics
TWA
Time-Weighted Average
U.S.
United States
VOC
Volatile Organic Compound
WHO
World Health Organization
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EXECUTIVE SUMMARY
TSCA § 6(b)(4) requires the U.S. Environmental Protection Agency (EPA) to establish a risk evaluation
process. In performing risk evaluations for existing chemicals, EPA is directed to "determine whether a
chemical substance presents an unreasonable risk of injury to health or the environment, without
consideration of costs or other non-risk factors, including an unreasonable risk to a potentially exposed
or susceptible subpopulation identified as relevant to the risk evaluation by the Administrator under
the conditions of use." In December of 2016, EPA published a list of 10 chemical substances that are
the subject of the Agency's initial chemical risk evaluations (81 FR 91927). as required by TSCA §
6(b)(2)(A). Methylene chloride was one of these chemicals.
TSCA § 6(b)(4)(D) requires that EPA publish the scope of the risk evaluation to be conducted, including
the hazards, exposures, conditions of use and potentially exposed or susceptible subpopulations that
the Administrator expects to consider. This document fulfills the TSCA § 6(b)(4)(D) requirement for
methylene chloride.
This document presents the scope of the risk evaluation to be conducted for methylene chloride. If a
hazard, exposure, condition of use or potentially exposed or susceptible subpopulation has not been
discussed, EPA, at this point in time, is not intending to include it in the scope of the risk evaluation. As
per the rulemaking, Procedures for Chemical Risk Evaluation Under the Amended Toxic Substances
Control Act (TSCA), with respect to conditions of use in conducting a risk evaluation under TSCA, EPA
will first identify "circumstances" that constitute "conditions of use" for each chemical. While EPA
interprets this as largely a factual determination—i.e., EPA is to determine whether a chemical
substance is actually involved in one or more of the activities listed in the definition—the
determination will inevitably involve the exercise of some discretion.
To the extent practicable, EPA has aligned this scope document with the approach set forth in the risk
evaluation process rule; however, the scope documents for the first 10 chemicals in the risk evaluation
process differ from the scope documents that EPA anticipates publishing in the future. Time
constraints have resulted in scope documents for the first 10 chemicals that are not as refined or
specific as future scope documents are anticipated to be.
Because there was insufficient time for EPA to provide an opportunity for comment on a draft of this
scope document, as it intends to do for future scope documents, EPA will publish and take public
comment on a problem formulation document which will refine the current scope, as an additional
interim step, prior to publication of the draft risk evaluation for methylene chloride. This problem
formulation is expected to be released within approximately 6 months of publication of the scope.
Methylene chloride, also known as dichloromethane and DCM, is a volatile and high production
volume (HPV) chemical that is used as a solvent in a wide range of industrial, commercial and
consumer applications. Methylene chloride is subject to a number of federal and state regulations and
reporting requirements. In 2014 EPA assessed the risk from methylene chloride in consumer and
commercial paint removal, the Agency determined that those risks were unreasonable and, on January
19, 2017, proposed restrictions under TSCA section 6 to address the risks from methylene chloride in
paint and coating removal by consumers and most commercial users (82 FR 7464, January 19, 2017).
Methylene chloride is a reportable Toxics Release Inventory (TRI) chemical under Section 313 of the
Emergency Planning and Community Right-to-Know Act (EPCRA) since 1987. It is designated a
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Hazardous Air Pollutant (HAP) under the Clean Air Act (CAA), a hazardous waste under the
Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and a regulated
drinking water contaminant under the Safe Drinking Water Act (SDWA), and products containing
methylene chloride are required to be labeled under the Consumer Product Safety Act (CPSA).
Information on domestic manufacture, processing and use of methylene chloride is available to EPA
through its Chemical Data Reporting (CDR) Rule, issued under TSCA. In 2015, more than 260 million lbs
of methylene chloride was reported to be manufactured (including imported) in the U.S. According to
the ICIS chemical profile in 2005, the primary uses for methylene chloride are paint stripping and
removal (30%), adhesives (22%), pharmaceuticals (11%), metal cleaning (8%), aerosols (8%), chemical
processing (8%), flexible polyurethane foam (5%) and miscellaneous (8%).
The initial conceptual models presented in Section 2 identify conditions of use; exposure pathways
(e.g., media); exposure routes (e.g., inhalation, dermal, oral); potentially exposed populations,
including potentially exposed or susceptible subpopulations; and hazards EPA expects to evaluate
based on the inherent hazards of the chemical.
This document presents the occupational scenarios in which workers and occupational non-users may
be exposed to methylene chloride during a variety of conditions of use, such as manufacturing,
processing and uses in paint removal, adhesives and degreasing. EPA expects that the highest
exposures to methylene chloride generally involve workers in industrial and commercial settings.
Methylene chloride can be found in numerous products and can, therefore, result in exposures to
commercial and consumer users. This document also presents the consumer conceptual model which
indicates exposures occurring from methylene chloride containing products in either indoor or outdoor
environments. For methylene chloride, EPA believes that workers, consumers, and bystanders as well
as certain other groups of individuals may experience greater exposures than the general population.
EPA will evaluate whether other groups of individuals within the general population may be exposed
via pathways that are distinct from the general population due to unique characteristics (e.g., life
stage, behaviors, activities, duration) or have greater susceptibility than the general population, and
should therefore be considered relevant potentially exposed or susceptible subpopulations for
purposes of this risk evaluation.
Exposures to the general population may occur from industrial releases. The Toxics Release Inventory
(TRI) identified releases of methylene chloride to air, water and land, with the majority being releases
to air. The general population can be exposed to methylene chloride through inhalation, oral and
dermal pathways due to its widespread presence in a variety of environmental media such as in air,
drinking water, ground water and/or surface water. EPA considers workers, occupational non-users,
consumers and bystanders and certain groups of individuals who may experience greater exposures
due to proximity to conditions of use, as potentially exposed or susceptible subpopulations.
Methylene chloride has been the subject of numerous human health reviews including EPA's
Integrated Risk Information System (IRIS) Toxicological Review and Agency for Toxic Substances and
Disease Registry's (ATSDR's) Toxicological Profile and a 2014 assessment of risk in consumer and
commercial paint removal. Along with other reasonably available information, EPA will use the existing
TSCA risk assessments to inform its development of the methylene chloride risk evaluation. A number
of targets of toxicity from exposures to methylene chloride have been identified in animal and human
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studies for both oral and inhalation exposures. EPA expects to consider hazard endpoints for: acute
toxicity (via central nervous system [CNS] depression which can result in death), irritation, liver toxicity
and neurotoxicity. Methylene chloride is also likely carcinogenic in humans. If additional hazard
concerns are identified during the systematic review of the literature, these will also be considered.
These hazards will be evaluated based on the specific exposure scenarios identified.
The initial analysis plan describes EPA's plan for conducting systematic review of readily available
information and identification of assessment approaches to be used in conducting the risk evaluation
for methylene chloride. The initial analysis plan will be used to develop the problem formulation and
final analysis plan for the risk evaluation of methylene chloride.
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1 INTRODUCTION
This document presents the scope of the risk evaluation to be conducted for methylene chloride. If a
condition of use has not been discussed, U.S. Environmental Protection Agency (EPA), at this point in
time, is not intending to include that condition of use in the scope of the risk evaluation. Moreover,
during problem formulation EPA may determine that not all conditions of use mentioned in this scope
will be included in the risk evaluation. Any condition of use that will not be evaluated will be clearly
described in the problem formulation document.
On June 22, 2016, the Frank R. Lautenberg Chemical Safety for the 21st Century Act, which amended
the Toxic Substances Control Act (TSCA), the nation's primary chemicals management law, was signed
into law. The new law includes statutory requirements and deadlines for actions related to conducting
risk evaluations of existing chemicals.
TSCA § 6(b)(4) requires the EPA to establish a risk evaluation process. In performing risk evaluations for
existing chemicals, EPA is directed to "determine whether a chemical substance presents an
unreasonable risk of injury to health or the environment, without consideration of costs or other non-
risk factors, including an unreasonable risk to a potentially exposed or susceptible subpopulation
identified as relevant to the risk evaluation by the Administrator under the conditions of use."
In December of 2016, EPA published a list of 10 chemical substances that are the subject of the
Agency's initial chemical risk evaluations (81 FR 91927). as required by TSCA § 6(b)(2)(A). These
10 chemical substances were drawn from the 2014 update of EPA's TSCA Work Plan for Chemical
Assessments, a list of chemicals that EPA identified in 2012 and updated in 2014 (currently totaling
90 chemicals) for further assessment under TSCA. EPA's designation of the first 10 chemical substances
constituted the initiation of the risk evaluation process for each of these chemical substances, pursuant
to the requirements of TSCA § 6(b)(4).
TSCA § 6(b)(4)(D) requires that EPA publish the scope of the risk evaluation to be conducted, including
the hazards, exposures, conditions of use and potentially exposed or susceptible subpopulations that
the Administrator expects to consider. On February 14, 2017, EPA convened a public meeting to
receive input and information to assist the Agency in its efforts to establish the scope of the risk
evaluations under development for the ten chemical substances designated in December 2016 for risk
evaluations pursuant to TSCA. EPA provided the public an opportunity to identify information, via oral
comment or by submission to a public docket, specifically related to the conditions of use for the ten
chemical substances. EPA used this information in developing this scope document, which fulfills the
TSCA § 6(b)(4)(D) requirement for methylene chloride.
As per the rulemaking, Procedures for Chemical Risk Evaluation Under the Amended Toxic Substances
Control Act (TSCA), in conducting a risk evaluation under TSCA EPA will first identify "circumstances"
that constitute "conditions of use" for each chemical. While EPA interprets this as largely a factual
determination —i.e., EPA is to determine whether a chemical substance is actually involved in one or
more of the activities listed in the definition—the determination will inevitably involve the exercise of
some discretion. Based on legislative history, statutory structure and other evidence of Congressional
intent, EPA has determined that certain activities may not generally be considered to be conditions of
use. In exercising its discretion, for example, EPA would not generally consider that a single
unsubstantiated or anecdotal statement (or even a few isolated statements) on the internet that a
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chemical can be used for a particular purpose would necessitate concluding that this represented part
of the chemical substance's "conditions of use." As a further example, although the definition could be
read literally to include all intentional misuses (e.g., inhalant abuse), as a "known" or "reasonably
foreseen" activity in some circumstances, EPA does not generally intend to include such activities in
either a chemical substance's prioritization or risk evaluation. In addition, EPA interprets the mandates
under section 6(a)-(b) to conduct risk evaluations and any corresponding risk management to focus on
uses for which manufacture, processing, or distribution in commerce is intended, known to be
occurring, or reasonably foreseen (i.e., is prospective or on-going), rather than reaching back to
evaluate the risks associated with legacy uses, associated disposal, and legacy disposal, and interprets
the definition of "conditions of use" in that context. For instance, the conditions of use for purposes of
section 6 might reasonably include the use of a chemical substance in insulation where the
manufacture, processing or distribution in commerce for that use is prospective or on-going, but would
not include the use of the chemical substance in previously installed insulation, if the manufacture,
processing or distribution for that use is not prospective or on-going. In other words, EPA interprets
the risk evaluation process of section 6 to focus on the continuing flow of chemical substances from
manufacture, processing and distribution in commerce into the use and disposal stages of their
lifecycle. That said, in a particular risk evaluation, EPA may consider background exposures from legacy
use, associated disposal, and legacy disposal as part of an assessment of aggregate exposure or as a
tool to evaluate the risk of exposures resulting from non-legacy uses.
Furthermore, in exercising its discretion under section 6(b)(4)(D) to identify the conditions of use that
EPA expects to consider in a risk evaluation, EPA believes it is important for the Agency to have the
discretion to make reasonable, technically sound scoping decisions in light of the overall objective of
determining whether chemical substances in commerce present an unreasonable risk. Consequently,
EPA may, on a case-by case basis, exclude certain activities that EPA has determined to be conditions
of use in order to focus its analytical efforts on those exposures that are likely to present the greatest
concern meriting an unreasonable risk consideration. For example, EPA intends to exercise discretion
in addressing circumstances where the chemical substance subject to scoping is unintentionally
present as an impurity in another chemical substance that is not the subject of the pertinent scoping,
in order to determine which risk evaluation the potential risks from the chemical substance should be
addressed in. As an additional example, EPA may, on a case-by-case basis, exclude uses that EPA has
sufficient basis to conclude would present only "de minimis" exposures. This could include uses that
occur in a closed system that effectively precludes exposure, or use as an intermediate. During the
scoping phase, EPA may also exclude a condition of use that has been adequately assessed by another
regulatory agency, particularly where the other agency has effectively managed the risks.
The situations identified above are examples of the kinds of discretion that EPA will exercise in
determining what activities constitute conditions of use, and what conditions of use are to be included
in the scope of any given risk evaluation. See the preamble to Procedures for Chemical Risk Evaluation
Under the Amended Toxic Substances Control Act (TSCA) for further discussion of these issues.
To the extent practicable, EPA has aligned this scope document with the approach set forth in the risk
evaluation process rule; however, the scope documents for the first 10 chemicals in the risk evaluation
process differ from the scope documents that EPA anticipates publishing in the future. The first 10
chemical substances were not subject to the prioritization process that will be used in the future in
accordance with amendments to TSCA. EPA expects to collect and screen much of the relevant
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information about chemical substances that will be subject to the risk evaluation process during and
before prioritization. The volume of data and information about the first 10 chemicals that is available
to EPA is extremely large and EPA is still in the process of reviewing it, since the Agency had limited
ability to process the information gathered before issuing the scope documents for the first 10
chemicals. As a result of the statutory timeframes, EPA had limited time to process all of the
information gathered during scoping for the first 10 chemicals within the time provided in the statute
for publication of the scopes after initiation of the risk evaluation process. For these reasons, EPA's
initial screenings and designations with regard to applicability of data (e.g., on-topic vs. off-topic
information and data) may change as EPA progresses through the risk evaluation process. Likewise, the
Conceptual Models and Analysis Plans provided in the first 10 chemical scopes are designated as
"Initial" to indicate that EPA expects to further refine them during problem formulation.
The aforementioned time constraints and uncertainty associated with developing the risk evaluation
process rule has resulted in scope documents for the first 10 chemicals that are not as refined or
specific as future scope documents are anticipated to be. In addition, there was insufficient time for
EPA to provide an opportunity for comment on a draft of this scope document, as it intends to do for
future scope documents. For these reasons, EPA will publish and take public comment on a problem
formulation document which will refine the current scope, as an additional interim step, prior to
publication of the draft risk evaluations for the first 10 chemicals. This problem formulation is expected
to be released within approximately 6 months of publication of the scope.
1.1 Regulatory History
EPA conducted a search of existing domestic and international laws, regulations and assessments
pertaining to methylene chloride. EPA compiled this summary from data available from federal, state,
international and other government sources, as cited in Appendix A. During risk evaluation, EPA will
evaluate and consider the impact of these existing laws and regulations in the problem formulation
step to determine what, if any further analysis might be necessary as part of the risk evaluation.
Federal Laws and Regulations
Methylene chloride is subject to federal statutes or regulations, other than TSCA, that are
implemented by other offices within EPA and/or other federal agencies/departments. A summary of
federal laws, regulations and implementing authorities is provided in Appendix A.l.
State Laws and Regulations
Methylene chloride is subject to state statutes or regulations implemented by state agencies or
departments. A summary of state laws, regulations and implementing authorities is provided in
Appendix A.2.
Laws and Regulations in Other Countries and International Treaties or Agreements
Methylene chloride is subject to statutes or regulations in countries other than the United States
and/or international treaties and/or agreements. A summary of these laws, regulations, treaties and/or
agreements is provided in Appendix A.3.
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1.2 Assessment History
EPA has identified assessments conducted by other EPA Programs and other organizations (see Table
1-1). Depending on the source, these assessments may include information on conditions of use,
hazards, exposures and potentially exposed or susceptible subpopulations—information useful to EPA
in preparing this scope for risk evaluation. Table 1-1 shows the assessments that have been conducted.
In addition to using this information, EPA intends to conduct a full review of the data collected (see
Methylene Chloride (CASRN 75-09-2) Bibliography: Supplemental File for the TSCA Scope Document
EPA-HQ-QPPT-2016-0742) using the literature search strategy (see Strategy for Conducting Literature
Searches for Methylene Chloride: Supplemental File for the TSCA Scope Document EPA-HQ-QPPT-2016-
0742) to ensure that EPA is considering information that has been made available since these
assessments were conducted.
In the final 2014 risk assessment, U.S. EPA (2014a) identified risks from methylene chloride in
consumer and commercial paint removal. The Agency determined those risks were unreasonable and,
on January 19, 2017, proposed restrictions under TSCA section 6 to address the risks from methylene
chloride in paint and coating removal by consumers and most commercial users (82 FR 7464. January
19, 2017). Along with other reasonably available information, EPA will use the existing TSCA risk
assessments to inform its development of the methylene chloride risk evaluation.
Table 1-1. Assessment History of Methylene Chloride
Authoring Organization
Assessment
EPA Assessments
U.S. EPA, Office of Pollution Prevention and Toxics
(OPPT)
TSCA Work Plan Chemical Risk Assessment
Methylene Chloride: Paint Stripping Use CASRN:
75-09-2 U.S. EPA (2014a)
U.S. EPA, Integrated Risk Information System (IRIS)
Toxicological Review of Dichloromethane
(Methylene Chloride) (CAS No. 75-09-2) U.S. EPA
(2011)
U.S. EPA, Office of Water (OW)
Ambient Water Quality Criteria for the Protection
of Human Health U.S. EPA (2015)
Other U.S.-Based Organizations
Agency for Toxic Substances and Disease Registry
(ATSDR)
Toxicological Profile for Methylene Chloride
ATSDR (2000) and addendum ATSDR (2010)
National Advisory Committee for Acute Exposure
Guideline Levels for Hazardous Substances
(NAC/AEGL Committee)
Interim Acute Exposure Guideline Levels (AEGL)
for Methylene Chloride NAC/AEGL (2008)
U.S. National Academies, National Research
Council (NRC)
Spacecraft Maximum Allowable Concentrations
(SMAC) for Selected Airborne Contaminants:
Methylene chloride (Volume 2) NRC (1996)
National Toxicology Program (NTP), National
Institutes of Health (NIH)
Report on Carcinogens, Twelfth Edition,
Dichloromethane NTP (2016)
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Authoring Organization
Assessment
Occupational Safety and Health Administration
(OSHA)
Occupational Exposure to Methylene Chloride
OSHA (1997)
California Environmental Protection Agency, Office
of Environmental Health Hazard Assessment
(OEHHA)
Acute Reference Exposure Level (REL) and
Toxicity Summary for Methylene Chloride OEHHA
(2008)
Public Health Goal for Methylene Chloride in
Drinkine Water OEHHA (2000)
International
Organisation for Economic Co-operation and
Development (OECD), Cooperative Chemicals
Assessment Program (CoCAP)
Dichloromethane: SIDS Initial Assessment Profile
OECD (2011)
International Agency for Research on Cancer
(IARC)
IARC Monographs on the Evaluation of
Carcinogenic Risks to Humans Volume 110 IARC
(2016)
World Health Organization (WHO)
Air Quality Guidelines for Europe WHO (2000)
Government of Canada, Environment Canada,
Health Canada
Dichloromethane. Priority substances list
assessment report. Health Canada (1993)
National Industrial Chemicals Notification and
Assessment Scheme (NICNAS), Australian
Government
Human Health Tier II Assessment for Methane,
dichloro- CAS Number: 75-09-2 NICNAS (2016)
1.3 Data and Information Collection
EPA/OPPT generally applies a process and workflow that includes: (1) data collection; (2) data
evaluation; and (3) data integration of the scientific data used in risk assessments developed under
TSCA. Scientific analysis is often iterative in nature as new knowledge is obtained. Hence, EPA/OPPT
expects that multiple refinements regarding data collection will occur during the process of risk
evaluation.
Data Collection: Data Search
EPA/OPPT conducted chemical-specific searches for data and information on: physical and chemical
properties; environmental fate and transport; conditions of use information; environmental exposures,
human exposures, including potentially exposed or susceptible subpopulations; ecological hazard,
human health hazard, including potentially exposed or susceptible subpopulations.
EPA/OPPT designed its initial data search to be broad enough to capture a comprehensive set of
sources containing data and/or information potentially relevant to the risk evaluation. Generally, the
search was not limited by date and was conducted on a wide range of data sources, including but not
limited to: peer-reviewed literature and gray literature (e.g., publicly-available industry reports, trade
association resources, government reports). When available, EPA/OPPT relied on the search strategies
from recent assessments, such as EPA Integrated Risk Information System (IRIS) assessments and the
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National Toxicology Program's (NTP) Report on Carcinogens, to identify relevant references and
supplemented these searches to identify relevant information published after the end date of the
previous search to capture more recent literature. Strategy for Conducting Literature Searches for
Methylene Chloride: Supplemental File for the TSCA Scope Document provides details about the data
sources and search terms that were used in the initial search.
Data Collection: Data Screening
Following the data search, references were screened and categorized using selection criteria outlined
in supplemental document: Strategy for Conducting Literature Searches for Methylene Chloride:
Supplemental File for the TSCA Scope Document. Titles and abstracts were screened against the criteria
as a first step with the goal of identifying a smaller subset of the relevant data to move into the
subsequent data extraction and data evaluation steps. Prior to full-text review, EPA/OPPT anticipates
refinements to the search and screening strategies, as informed by an evaluation of the performance
of the initial title/abstract screening and categorization process.
The categorization scheme (or tagging structure) used for data screening varies by scientific discipline
(i.e., physical and chemical properties; environmental fate and transport; chemical use/conditions of
use information; human and environmental exposures, including potentially exposed or susceptible
subpopulations identified by virtue of greater exposure; human health hazard, including potentially
exposed or susceptible subpopulations identified by virtue of greater susceptibility; and ecological
hazard), but within each data set, there are two broad categories or data tags: (1) on-topic references
or (2) off-topic references. On-topic references are those that may contain data and/or information
relevant to the risk evaluation. Off-topic references are those that do not appear to contain data or
information relevant to the risk evaluation. The supplemental document: Strategy for Conducting
Literature Searches for Methylene Chloride: Supplemental File for the TSCA Scope Document discusses
the inclusion and exclusion criteria that EPA/OPPT used to categorize references as on-topic or off-
topic.
Additional data screening using sub-categories (or sub-tags) was also performed to facilitate further
sorting of data/information - for example, identifying references by source type (e.g., published peer-
reviewed journal article, government report); data type (e.g., primary data, review article); human
health hazard (e.g., liver toxicity, cancer, reproductive toxicity); or chemical-specific and use-specific
data or information. These sub-categories are described in supplemental document: Strategy for
Conducting Literature Searches for Methylene Chloride: Supplemental File for the TSCA Scope
Document and will be used to organize the different streams of data during the stages of data
evaluation and data integration steps of systematic review.
Results of the initial search and categorization results can be found in the Methylene Chloride (CASRN
75-09-2) Bibliography: Supplemental File for the TSCA Scope Document. This document provides a
comprehensive list (bibliography) of the sources of data identified by the initial search and the initial
categorization for on-topic and off-topic references. Because systematic review is an iterative process,
EPA/OPPT expects that some references may move from the on-topic to the off-topic categories, and
vice versa. Moreover, targeted supplemental searches may also be conducted to address specific
needs for the analysis phase (e.g., to locate specific data needed for modeling); hence, additional on-
topic references not initially identified in the initial search may be identified as the systematic review
process proceeds.
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2 SCOPE OF THE EVALUATION
As required by TSCA, the scope of the risk evaluation identifies the conditions of use, hazards,
exposures and potentially exposed or susceptible subpopulations that the Administrator expects to
consider. To communicate and visually convey the relationships between these components, EPA is
including an initial life cycle diagram and initial conceptual models that describe the actual or potential
relationships between methylene chloride and human and ecological receptors. An initial analysis plan
is also included which identifies, to the extent feasible, the approaches and methods that EPA may use
to assess exposures, effects (hazards) and risks under the conditions of use for methylene chloride. As
noted previously, EPA intends to refine this analysis plan during the problem formulation phase of risk
evaluation.
2.1 Physical and Chemical Properties
Physical-chemical properties influence the environmental behavior and the toxic properties of a
chemical, thereby informing the potential conditions of use, exposure pathways and routes and
hazards that EPA intends to consider. For scope development, EPA considered the measured or
estimated physical-chemical properties set forth in Table 2-1.
Table 2-1. Physical and Chemical Properties of Methylene Chloride
Property
Valuea
References
Molecular formula
CH2CI2
Molecular weight
84.93 g/mol
Physical form
Colorless liquid; sweet, pleasant odor
resembling chloroform
U.S. Coast Guard (1984)
Melting point
-95°C
O'Neil (2013)
Boiling point
39.7°C
O'Neil (2013)
Density
1.33 g/cm3 at 20°C
O'Neil (2013)
Vapor pressure
435 mmHg at 25°C
Boublfk et al. (1984)
Vapor density
2.93 (relative to air)
Holbrook (2003)
Water solubility
13 g/L at 25°C
Horvath (1982)
Octanol/water partition
coefficient (log Kow)
1.25
Hansch et al. (1995)
Henry's Law constant
0.00325 atm-m3/mole
Leighton and Calo (1981)
Flash point
Not readily available
Autoflammability
Not readily available
Viscosity
0.437 mPa-s at 20°C
Rossberg et al. (2011)
Refractive index
1.4244 at 20°C
O'Neil (2013)
Page 18 of 72
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Property
Valuea
References
Dielectric constant
9.02 at 20°C
Laurence et al. (1994)
a Measured unless otherwise noted.
2.2 Conditions of Use
TSCA § 3(4) defines the conditions of use as "the circumstances, as determined by the Administrator,
under which a chemical substance is intended, known, or reasonably foreseen to be manufactured,
processed, distributed in commerce, used, or disposed of."
2.2.1 Data and Information Sources
As the first step in preparing these scope documents, EPA identified, based on reasonably available
information, the conditions of use for the subject chemicals. As further described in this document,
EPA searched a number of available data sources (e.g., Use and Market Profile for Methylene Chloride,
EPA-HQ-QPPT-2016-0742). Based on this search, EPA published a preliminary list of information and
sources related to chemical conditions of use (see Preliminary Information on Manufacturing,
Processing, Distribution, Use, and Disposal: Methylene Chloride, EPA-HQ-QPPT-2016-0742-0003) prior
to a February 2017 public meeting on scoping efforts for risk evaluation convened to solicit comment
and input from the public. EPA also convened meetings with companies, industry groups, chemical
users and other stakeholders to aid in identifying conditions of use and verifying conditions of use
identified by EPA. The information and input received from the public and stakeholder meetings has
been incorporated into this scope document to the extent appropriate, as indicated in Table 2-3. Thus,
EPA believes the manufacture, processing, distribution, use and disposal activities identified in these
documents constitute the intended, known, and reasonably foreseen activities associated with the
subject chemicals, based on reasonably available information. The documents do not, in most cases,
specify whether activity under discussion is intended, known, or reasonably foreseen, in part due to
the time constraints in preparing these documents.
2.2.2 Identification of Conditions of Use
As part of the scope, an initial life cycle diagram is provided (Figure 2-1) depicting the conditions of use
that are within the scope of the risk evaluation during various life cycle stages including manufacturing,
processing, use (industrial, commercial, consumer; when distinguishable), distribution and disposal.
The information is grouped according to Chemical Data Reporting (CDR) processing codes and use
categories (including functional use codes for industrial uses and product categories for commercial
and consumer uses), in combination with other data sources (e.g., published literature and
consultation with stakeholders), to provide an overview of conditions of use. EPA notes that some
subcategories may be grouped under multiple CDR categories.
For the purposes of this scope, CDR definitions were used. CDR use categories include the following:
"industrial use" means use at a site at which one or more chemicals or mixtures are manufactured
(including imported) or processed. "Commercial use" means the use of a chemical or a mixture
containing a chemical (including as part of an article) in a commercial enterprise providing saleable
goods or services. "Consumer use" means the use of a chemical or a mixture containing a chemical
(including as part of an article, such as furniture or clothing) when sold to or made available to
consumers for their use (U.S. EPA. 2016c).
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To understand conditions of use relative to one another and associated potential exposures under
those conditions of use, the initial life cycle diagram includes the production volume associated with
each stage of the life cycle, as reported in the 2016 CDR reporting (U.S. EPA. 2016c). when the volume
was not claimed confidential business information (CBI). The 2016 CDR reporting data for methylene
chloride are provided in Table 2-2 from EPA's CDR database.
Table 2-2. Production Volume of Methylene Chloride in CDR Reporting Period (2012 to 2015)a
Reporting Year
2012
2013
2014
2015
Total Aggregate
Production Volume (lbs)
230,896,388
230,498,027
248,241,495
263,971,494
aThe CDR data for the 2016 reporting period is available via ChemView (https://iava.eoa.gov/chemview) (U.S. EPA. 2016c).
Because of an ongoing CBI substantiation process required by amended TSCA, the CDR data available in the scope
document is more specific than currently in ChemView.
Figure 2-1 depicts the initial life cycle diagram of methylene chloride from manufacture to the point of
disposal. EPA identified the use categories by reviewing the industrial processing use activities, and
commercial and consumer use product categories reported in the 2016 CDR. Then, EPA identified the
subcategories by supplementing CDR data with information from Preliminary Information on
Manufacturing, Processing, Distribution, Use, and Disposal: Methylene Chloride and Use and Market
Profile for Methylene Chloride, both available in the public docket (EPA-HQ-QPPT-2016-0742). For risk
evaluations, EPA will assess each use subcategory by identifying all potential sources of release and
human exposure associated with that subcategory.
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MFG/IMPORT
PROCESSING
INDUSTRIAL, COMMERCIAL, CONSUMER USES3
RELEASES and WASTE DISPOSAL
Solvents for Cleaning or Degreasing
(Volume CBI)
Adhesives and Sealants
(Volume CBI)
e.g., glues and caulks
Paints and Coatings
(> 839,000 lbs)
Including Paint and coating removers and
adhesive removersb
Metal Products
(Volume CBI)
Fabric, Textile, and Leather Products
(Volume CBI)
Automotive Care Products
(11,000 lbs)
Apparel and Footwear Care Products
(Volume CBI)
See Figure 2-4 for Environmental
Releases and Wastes
Laundry and Dishwashing Products
(Volume CBI)
Manufacturing (includes import)
Lubricants and Greases
(187,000 lbs)
Processing
Other Uses including
Building/Construction Materials Not Covered
Elsewhere; Solvents (which become part of
productformation or mixture); Processing Aids
Not Otherwise Listed; Propellants and Blowing
Agents; Arts, Crafts and Hobby Materials;
Functional fluids (closed systems); Laboratory
Chemicals
Uses. At the scope level of detail in the life
cycle diagram EPA is not distinguishing
between industrial/commercial/consumer
uses. The differences between these uses
will be further investigated and defined
during risk evaluation.
Recycling
(Volume CBI)
Repackaging
(> 227,000 lbs)
Manufacturing
(includes import)
(264 million lbs)
Processing as Reactant
(Volume CBI)
e.g., intermediate for
refrigerant manufacture
Incorporated into
Formulation, Mixture
or Reaction Product
(> 557,000 lbs)
e.g., Polyurethane Foam
Blowing
Emissions to Air
Liquid Wastes
Wastewater
Solid Wastes
Figure 2-1. Initial Methylene Chloride Life Cycle Diagram
The initial life cycle diagram depicts the conditions of use that are within the scope of the risk evaluation during various life cycle stages
including manufacturing, processing, use (industrial, commercial, consumer), distribution and disposal. The production volumes shown are
for reporting year 2015 from the 2016 CDR reporting period (U.S. EPA. 2016c). Activities related to distribution (e.g., loading and unloading)
will be considered throughout the methylene chloride life cycle, rather than using a single distribution scenario.
aSee Table 2-3 for additional uses not mentioned specifically in this diagram.
b This includes uses assessed in the U.S. EPA (2014a) risk assessment and therefore those uses are out of scope for the risk evaluation.
c Wastewater: combination of water and organic liquid, where the organic content is <50%. Liquid wastes: combination of water and organic liquid, where the organic
content is >50%.
Page 21 of 72
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Descriptions of several of the industrial, commercial and consumer use categories identified from the
2016 CDR and included in the initial life cycle diagram are summarized below (U.S. EPA. 2016c). The
descriptions provide a brief overview of the use category; Appendix B contains more detailed
descriptions (e.g., process descriptions and worker activities) for each manufacturing, processing, use
and disposal category. The descriptions provided below are primarily based on the corresponding
industrial function category and/or commercial and consumer product category descriptions from the
2016 CDR and can be found in EPA's Instructions for Reporting 20 lemical Data Reporting
(U.S. EPA. 2016a).
The "Solvents for Cleaning and Degreasing" category encompasses chemical substances used to
dissolve oils, greases and similar materials from a variety of substrates including metal surfaces,
glassware and textiles. This category includes the use of methylene chloride in vapor degreasers and
cold cleaners and in industrial, commercial and consumer aerosol degreasing products. Methylene
chloride degreasers are often designed to clean electronic parts, electric motors and other water-
sensitive parts in industrial and commercial settings. Methylene chloride is also found in products
available to consumers such as brush cleaners or products designed to remove oil and grease from
electronic or mechanical parts.
The "Adhesives and Sealants" category encompasses chemical substances contained in adhesive and
sealant products used to fasten other materials together. The adhesives and sealants are found in both
liquid and aerosol forms. Examples include adhesives for bonding laminate to particle board or other
surfaces, foam to textiles, fiberglass to metal ductwork, carpet installation and cement for bonding
acrylic.
The "Paints and Coatings" category encompasses chemical substances used in a variety of paints,
varnishes, lacquers or other types of coatings used on a variety of substrates including wood and
metal. This category also covers paints and coatings removal uses, which include uses addressed in a
previous risk evaluation. Both of these categories have industrial, commercial and consumer uses with
products used in liquid, aerosol and paste forms.
The "Metal Products Not Covered Elsewhere" category encompasses chemical substances contained
in metal products not covered elsewhere that are intended for consumer or commercial use. Examples
of metal products not covered elsewhere include metal products produced by forging, stamping,
plating, turning, and other processes; hand tools; metal tubing/pipes/duct work; wire fencing;
tableware; and small appliances and cookware.
The "Fabric, Textile, and Leather Products Not Covered Elsewhere" category encompasses chemical
substances used to clean and treat a variety of textiles including upholstery and leather. This category
is primarily industrial and commercial users and the products are generally in liquid formulations.
The "Automotive Care Products" category encompasses chemical substances contained in products
used to seal leaks in car air conditioners or used in auto air conditioner refrigerants. These products are
generally used in aerosol form and used in both commercial and consumer settings.
The "Apparel and Footwear Care Products" category encompasses chemical substances contained in
apparel and footwear care products that are applied post-market. Examples of apparel and footwear
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care products include footwear polishes/waxes, garment waterproofing sprays, and stain repellents.
These products are primarily consumer or commercial uses.
The "Laundry and Dishwashing Products" category encompasses chemical substances contained in
laundry and dishwashing products and aids. Examples of laundry and dishwashing products include
detergents, fabric softeners, pre-soaks and prewashes to remove soil and stains, dryer sheets, bleach,
rinse aids, and film, lime and rust removers. These products are generally used as liquids, granular,
powders, gels, cakes, and flakes and used in both consumer and commercial settings.
The "Lubricants and Greases" category encompasses chemical substances contained in products used
in lubricants for cables, chains, metal parts, doors and dry film. These are primarily commercial or
industrial uses with both liquid and aerosol formulations.
Other uses of methylene chloride include uses in building/construction materials not covered
elsewhere; solvents (which become part of product formation or mixture); processing aids not
otherwise listed; propellants and blowing agents; arts, crafts and hobby materials (e.g., crafting glue
and cement), functional fluids (closed systems); laboratory chemicals; novelty items (e.g., Red Retro
Happy Dippy Drinking Bird).
Table 2-3 summarizes each life cycle stage and the corresponding categories and subcategories of
conditions of use for methylene chloride that EPA expects to consider in the risk evaluation. Using the
2016 CDR, EPA identified industrial processing or use activities, industrial function categories and
commercial and consumer use product categories. EPA identified the subcategories by supplementing
CDR data with other published literature and information obtained through stakeholder consultations.
For risk evaluations, EPA intends to consider each life cycle stage (and corresponding use categories
and subcategories) and assess relevant potential sources of release and human exposure associated
with that life cycle stage.
Table 2-3. Categories and Subcategories of Conditions of Use for Methylene Chloride
Life Cycle Stage
Categorya
Subcategory b
References
Manufacturing
Domestic
manufacturing
Manufacturing
U.S. EPA (2016c)
Import
Import
U.S. EPA (2016c)
Processing
Processing as a
reactant
Intermediate in industrial gas
manufacturing (e.g., manufacture
of fluorinated gases used as
refrigerants)
U.S. EPA (2016c): U.S. EPA
(2014a) Market profile
EPA-HQ-OPPT-2016-0742
Public Comments EPA-HQ-
OPPT-2016-0742-0016.
EPA-HQ-OPPT-2016-0742-
0017. EPA-HQ-OPPT-2016-
0742-0019
Intermediate for pesticide,
fertilizer, and other agricultural
chemical manufacturing
U.S. EPA (2016c)
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Life Cycle Stage
Categorya
Subcategory b
References
Processing
Processing as a
reactant
CBI function for petrochemical
manufacturing
U.S. EPA (2016c)
Intermediate for other chemicals
Public Comment EPA-HQ-
OPPT-2016-0742-0008
Incorporated into
formulation,
mixture, or
reaction product
Solvents (for cleaning or
degreasing), including
manufacturing of:
• All other basic organic
chemical
• Soap, cleaning compound
and toilet preparation
U.S. EPA (2016c)
Solvents (which become part of
product formulation or mixture),
including manufacturing of:
• All other chemical product
and preparation
• Paints and coatings
U.S. EPA (2016c)
Propellants and blowing agents
for all other chemical product
and preparation manufacturing
U.S. EPA (2016c)
Propellants and blowing agents
for plastics product
manufacturing
Use document EPA-HQ-
OPPT-2016-0742-0003.
Market profile EPA-HQ-
OPPT-2016-0742
Paint additives and coating
additives not described by other
codes for CBI industrial sector
U.S. EPA (2016c)
Laboratory chemicals for all other
chemical product and
preparation manufacturing
U.S. EPA (2016c). EPA-HQ-
OPPT-2016-0742-0005.
EPA-HQ-OPPT-2016-0742-
0014
Laboratory chemicals for CBI
industrial sectors
U.S. EPA (2016c)
Processing aid, not otherwise
listed for petrochemical
manufacturing
U.S. EPA (2016c)
Adhesive and sealant chemicals
in adhesive manufacturing
Use document EPA-HQ-
OPPT-2016-0742-0003 U.S.
EPA (2016c)
Page 24 of 72
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Life Cycle Stage
Categorya
Subcategory b
References
Processing
Incorporated into
formulation,
mixture, or
reaction product
Unknown function for oil and gas
drilling, extraction, and support
activities
Use document EPA-HQ-
OPPT-2016-0742-0003 U.S.
EPA (2016c)
Repackaging
Solvents (which become part of
product formulation or mixture)
for all other chemical product
and preparation manufacturing
Use document EPA-HQ-
OPPT-2016-0742-0003 U.S.
EPA (2016c)
CBI functions for all other
chemical product and
preparation manufacturing
Use document EPA-HQ-
OPPT-2016-0742-0003 U.S.
EPA (2016c)
Recycling
Recycling
U.S. EPA (2017)
Distribution in
commerce
Distribution
Distribution
Use document EPA-HQ-
OPPT-2016-0742-0003
Industrial,
commercial and
consumer uses
Solvents (for
cleaning or
degreasing)c
Batch vapor degreaser (e.g.,
open-top, closed-loop)
Use document EPA-HQ-
OPPT-2016-0742-0003:
U.S. EPA (2016c): Public
comment EPA-HQ-OPPT-
2016-0742-0017
In-line vapor degreaser (e.g.,
conveyorized, web cleaner)
Use document EPA-HQ-
OPPT-2016-0742-0003:
U.S. EPA (2016c): Public
comment EPA-HQ-OPPT-
2016-0742-0017
Cold cleaner
Use document EPA-HQ-
OPPT-2016-0742-0003:
U.S. EPA (2016c. 2014a)
Aerosol spray degreaser/cleaner
U.S. EPA (2016c): Use
document EPA-HQ-OPPT-
2016-0742-0003: Market
profile EPA-HQ-OPPT-
2016-0742: U.S. EPA
(2014a)
Page 25 of 72
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Life Cycle Stage
Categorya
Subcategory b
References
Industrial,
commercial and
consumer uses
Adhesives and
sealants
Single component glues and
adhesives and sealants and
caulks
Use document EPA-HQ-
OPPT-2016-0742-0003:
U.S. EPA (2016c): Public
Comments EPA-HQ-OPPT-
2016-0742-0005. EPA-HQ-
OPPT-2016-0742-0013.
EPA-HQ-OPPT-2016-0742-
0014. EPA-HQ-OPPT-2016-
0742-0017. EPA-HQ-OPPT-
2016-0742-0021. EPA-HQ-
OPPT-2016-0742-0033
Paints and
coatings including
paint and coating
removers d
Paints and coatings use and
paints and coating removers,
including furniture refinisher
U.S. EPA (2016c): U.S. EPA
(2014a); Market profile
EPA-HQ-OPPT-2016-0742
Public Comments EPA-HQ-
OPPT-2016-0742-0005.
EPA-HQ-OPPT-2016-0742-
0009. EPA-HQ-OPPT-2016-
0742-0014. EPA-HQ-OPPT-
2016-0742-0017. EPA-HQ-
OPPT-2016-0742-0021.
EPA-HQ-OPPT-2016-0742-
0025
Adhesive/caulk removers
Use document EPA-HQ-
OPPT-2016-0742-0003.
Market profile EPA-HQ-
OPPT-2016-0742
Metal products
not covered
elsewhere
Degreasers - aerosol and non-
aerosol degreasers and cleaners
e.g., coil cleaners
Market profile EPA-HQ-
OPPT-2016-0742 U.S. EPA
(2016c)
Fabric, textile and
leather products
not covered
elsewhere
Textile finishing and
impregnating/ surface treatment
products e.g. water repellant
Market profile EPA-HQ-
OPPT-2016-0742
Automotive care
products
Function fluids for air
conditioners: refrigerant,
treatment, leak sealer
Use document EPA-HQ-
OPPT-2016-0742-0003:
Market profile EPA-HQ-
OPPT-2016-0742 U.S. EPA
(2016c)
Interior car care - spot remover
Use document EPA-HQ-
OPPT-2016-0742-0003
Page 26 of 72
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Life Cycle Stage
Categorya
Subcategory b
References
Industrial,
commercial and
consumer uses
Automotive care
products
Degreasers: gasket remover,
transmission cleaners, carburetor
cleaner, brake quieter/cleaner
Use document EPA-HQ-
OPPT-2016-0742-
0003,Market profile EPA-
HQ-OPPT-2016-0742 U.S.
EPA (2016c)
Apparel and
footwear care
products
Post-market waxes and polishes
applied to footwear e.g. shoe
polish
Market profile EPA-HQ-
OPPT-2016-0742
Laundry and
dishwashing
products
Spot remover for apparel and
textiles
Use document EPA-HQ-
OPPT-2016-0742-0003
Lubricants and
greases
Liquid and spray lubricants and
greases
U.S. EPA (2016c): Use
document EPA-HQ-OPPT-
2016-0742-0003: Market
profile EPA-HQ-OPPT-
2016-0742: Public
Comment EPA-HQ-OPPT-
2016-0742-0021
Degreasers - aerosol and non-
aerosol degreasers and cleaners
U.S. EPA (2016c): Use
document EPA-HQ-OPPT-
2016-0742-0003: Market
profile EPA-HQ-OPPT-
2016-0742: Public
Comments EPA-HQ-OPPT-
2016-0742-0005. EPA-HQ-
OPPT-2016-0742-0014
Building/
construction
materials not
covered elsewhere
Cold pipe insulation
Use document EPA-HQ-
OPPT-2016-0742-0003
Solvents (which
become part of
product
formulation or
mixture)
All other chemical product and
preparation manufacturing
U.S. EPA (2016c)
Processing aid not
otherwise listed
In multiple manufacturing
sectors6
Use document EPA-HQ-
OPPT-2016-0742-0003:
Market profile EPA-HQ-
OPPT-2016-0742: U.S. EPA
(2016c)
Page 27 of 72
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Life Cycle Stage
Categorya
Subcategory b
References
Industrial,
commercial and
consumer uses
Propellants and
blowing agents
Flexible polyurethane foam
manufacturing
Market profile EPA-HQ-
OPPT-2016-0742
Arts, crafts and
hobby materials
Crafting glue and
cement/concrete
Use document EPA-HQ-
OPPT-2016-0742-0003
Other Uses
Laboratory chemicals - all other
chemical product and
preparation manufacturing
Use document EPA-HQ-
OPPT-2016-0742-0003:
Market profile EPA-HQ-
OPPT-2016-0742: U.S. EPA
(2016c)
Electrical equipment, appliance,
and component manufacturing
U.S. EPA (2016c). Public
Comment EPA-HQ-OPPT-
2016-0742-0017
Plastic and rubber products
U.S. EPA (2016c)
Other (CBI)
U.S. EPA (2016c)
Anti-adhesive agent - anti-spatter
welding aerosol
Use document EPA-HQ-
OPPT-2016-0742-0003:
Market profile EPA-HQ-
OPPT-2016-0742: Public
Comment EPA-HQ-OPPT-
2016-0742-0005
Oil and gas drilling, extraction,
and support activities
Use document EPA-HQ-
OPPT-2016-0742-0003:
U.S. EPA (2016c)
Extraction solvent for oils, waxes,
fats, spices and hops in
agricultural chemical
manufacturing and food
processing
Market profile EPA-HQ-
OPPT-2016-0742: U.S. EPA
(2016c)
Functional fluids (closed systems)
in pharmaceutical and medicine
manufacturing
U.S. EPA (2016c)
Toys, playground, and sporting
equipment - including novelty
articles (toys, gifts, etc.)
Use document EPA-HQ-
OPPT-2016-0742-0003:
U.S. EPA (2016c)
Page 28 of 72
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Life Cycle Stage
Categorya
Subcategory b
References
Industrial,
commercial and
consumer uses
Other Uses
Carbon remover, lithographic
printing cleaner, wood floor
cleaner, brush cleaner
Use document EPA-HQ-
OPPT-2016-0742-0003:
Market profile EPA-HQ-
OPPT-2016-0742: U.S. EPA
(2016c)
Disposal
Emissions to air
Emissions to air
U.S. EPA (2017)
Wastewater or
liquid wastes
Wastewater
Liquid wastes
Industrial pre-treatment
Industrial wastewater treatment
Publicly owned treatment works
(POTW)
Underground injection
Waste (solid
and/or liquid)
Municipal landfill
Hazardous landfill
Other land disposal
Municipal waste incinerator
Hazardous waste incinerator
Off-site waste transfer
aThese categories of conditions of use appear in the initial life cycle diagram, reflect CDR codes and broadly represent
conditions of use for methylene chloride in industrial and/or commercial settings.
bThese subcategories reflect more specific uses of methylene chloride.
c Reported for the following sectors in the 2016 CDR for manufacturing of: plastic materials and resins, plastics products,
miscellaneous, all other chemical product and preparation (U.S. EPA. 2016c).
d This includes uses assessed in the U.S. EPA (2014a) risk assessment and therefore those uses are out of scope for the risk
evaluation
e Reported for the following sectors in the 2016 CDR for manufacturing of: petrochemicals, plastic materials and resins,
plastics products, miscellaneous, all other chemical product and CBI (U.S. EPA. 2016c) which mav include chemical
processor for polycarbonate resins and cellulose triacetate - photographic film, developer (Market profile EPA-HQ-OPPT-
2016-0742).
Methylene chloride has known applications as a process solvent in paint removers and the
manufacture of pharmaceuticals and film coatings. It is used as an agent in urethane foam blowing and
in the manufacture of hydrofluorocarbon (HFC) refrigerants, such as HFC-32. It can also be found in
aerosol propellants and in solvents for electronics manufacturing, metal cleaning and degreasing and
furniture finishing. Additionally, it has been used for agricultural and food processing purposes such as
an extraction solvent for spice oleoresins and hops and for the removal of caffeine from coffee
(Processing Magazine. 2015; U.S. EPA. 2000a).
According to the ICIS (2005) chemical profile, the use percentages of methylene chloride by sector
were as follows: paint stripping and removal (30%), adhesives (22%), pharmaceuticals (11%), metal
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cleaning (8%), aerosols (8%), chemical processing (8%), flexible polyurethane foam (5%) and
miscellaneous (8%).
In the final 2014 risk assessment, U.S. EPA (2014a) identified risks from methylene chloride in
consumer and commercial paint removal. The Agency determined those risks were unreasonable and,
on January 19, 2017, proposed restrictions under TSCA section 6 to address the risks from methylene
chloride in paint and coating removal by consumers and most commercial users (82 FR 7464. January
19, 2017). While paint and coating removal falls under the conditions of use for methylene chloride,
scenarios already assessed in the 2014 risk assessment will not be re-evaluated in the risk evaluation to
which this scope applies. Therefore, this use is out of scope for the risk evaluation.
2.3 Exposures
For TSCA exposure assessments, EPA expects to evaluate exposures and releases to the environment
resulting from the conditions of use applicable to methylene chloride. Post-release pathways and
routes will be described to characterize the relationship or connection between the conditions of use
for methylene chloride and the exposure to human receptors, including potentially exposed or
susceptible subpopulations and ecological receptors. EPA will take into account, where relevant, the
duration, intensity (concentration), frequency and number of exposures in characterizing exposures to
methylene chloride.
2.3.1 Fate and Transport
Environmental fate includes both transport and transformation processes. Environmental transport is
the movement of the chemical within and between environmental media. Transformation occurs
through the degradation or reaction of the chemical with other species in the environment. Hence,
knowledge of the environmental fate of the chemical informs the determination of the specific
exposure pathways and potential human and environmental receptors EPA expects to consider in the
risk evaluation. Table 2-4 provides environmental fate data that EPA has identified and considered in
developing the scope for methylene chloride.
Table 2-4. Environmental Fate Characteristics of Methylene Chloride
Property or Endpoint
Valuea
References
Indirect photodegradation
107 days (estimated)
OECD (2011)
Hydrolysis half-life
18 months
OECD (2011)
Biodegradation
13% in 28 days (not readily
biodegradable) (aerobic sludge)
NITE (2002)
Bioconcentration factor (BCF)
2.0 to 5.4 (carp)
<6.4 to 40 (carp)
NITE (2002)
Bioaccumulation factor (BAF)
2.6 (estimated)
U.S. EPA (2012)
Organic carbon:water
partition coefficient (log Koc)
1.4 (estimated)
U.S. EPA (2012)
a Measured unless otherwise noted. Data retrieved from the 2014 EPA risk assessment on methylene chloride (U.S. EPA.
2014a).
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Releases of methylene chloride to the environment are likely to evaporate to the atmosphere, or if
released to soil, migrate to ground water. Methylene chloride is expected to undergo photooxidation
in the atmosphere but considering its photodegradation half-life (107 days) it is moderately persistent
and methylene chloride is expected to be subject to atmospheric transport.
Methylene chloride is not readily biodegradable but has been shown to biodegrade over a range of
rates under aerobic and anaerobic conditions. Measured BCFs for methylene chloride considered in the
2014 EPA risk assessment on methylene chloride (U.S. EPA. 2014a) are 40 (log BCF 1.60) or below. The
estimated bioaccumulation factor for methylene chloride is 2.6 (log BAF 0.4). Therefore, methylene
chloride is not considered to be bioaccumulative.
2.3.2 Releases to the Environment
Releases to the environment from conditions of use (e.g., industrial and commercial processes,
commercial or consumer uses resulting in down-the-drain releases) are one component of potential
exposure and may be derived from reported data that are obtained through direct measurement,
calculations based on empirical data and/or assumptions and models.
A source of information that EPA expects to consider in evaluating exposure are data reported under
the Toxics Release Inventory (TRI) program. Under the Emergency Planning and Community Right-to-
Know Act (EPCRA) Section 313 rule, methylene chloride is a TRI-reportable substance effective January
1, 1987.
Table 2-5 provides production-related waste managed data (also referred to as waste managed) for
methylene chloride reported by industrial facilities to the TRI program for 2015. Table 2-6 provides
more detailed information on the quantities released to air or water or disposed of on land.
Table 2-5. Summary of Methylene Chloride TRI Production-Related Waste Managed in 2015 (lbs)
Number of
Energy
Total Production
Facilities
Recycling
Recovery
Treatment
Releasesa,b
Related Waste
271
96,865,223
15,619,010
37,832,075
3,390,985
153,707,292
Data source: 2015 TRI Data (updated March 2017) (U.S. EPA. 2017).
aTerminology used in these columns may not match the more detailed data element names used in the TRI public data
and analysis access points.
b Does not include releases due to one-time event not associated with production such as remedial actions or
earthquakes.
In 2015, 271 facilities reported a total of about 153.7 million pounds of methylene chloride waste
managed. Of this total, about 96.9 million pounds were recycled, 15.6 million pounds were recovered
for energy, 37.8 million pounds were treated, and 3.4 million pounds were released into the
environment.
Of these releases, the majority, 75%, were released to air: 2.5 million pounds (stack and fugitive air
emissions), 2,366 pounds were released to water (surface water discharges), 114 thousand pounds
were released to land (of which Class I Underground Injection and Resource Conservation and
Recovery Act (RCRA) Subtitle C landfills are the primary disposal methods) and 713 thousand pounds
were released in other forms such as to waste brokers.
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Table 2-6. Summary of Methylene
Zhloride T
Rl Releases to the Environment in 2015 (lbs)
Number
of
Facilities
Air Releases
Water
Releases
Land Releases
Other Releasesa
Total
Releases
b
Stack Air
Releases
Fugitive
Air
Releases
Class 1
Under-
ground
Injection
RCRA
Subtitle
C
Landfills
All
other
Land
Disposal
a
Subtotal
1,279,661
1,262,485
59,711 36,091 18,199
Totals
271
2,542,146
2,366
114,001
713,241
3,371,754
Data source: 2015 TRI Data (updated March 2017) (U.S. EPA. 2017).
3 Terminology used in these columns may not match the more detailed data element names used in the TRI public data and analysis access points.
b These release quantities do include releases due to one-time events not associated with production such as remedial actions or earthquakes.
While production-related waste managed shown in Table 2-5 excludes any quantities reported as
catastrophic or one-time releases (TRI section 8 data), release quantities shown in Table 2-6 include
both production-related and non-routine quantities (TRI section 5 and 6 data). As a result, release
quantities may differ slightly and may further reflect differences in TRI calculation methods for
reported release range estimates (U.S. EPA. 2017).
Other sources of information provide evidence of releases of methylene chloride, including EPA
effluent guidelines (EGs) promulgated under the Clean Water Act (CWA), National Emission Standards
for Hazardous Air Pollutants (NESHAPs) promulgated under the Clean Air Act (CAA), or other EPA
standards and regulations that set legal limits on the amount of methylene chloride that can be
emitted to a particular media. EPA expects to consider these data in conducting the exposure
assessment component of the risk evaluation for methylene chloride.
EPA is aware of additional agency resources for methylene chloride emissions data, including National
Emissions Inventory (NEI) and the Discharge Monitoring Report (DMR) Pollutant Loading Tool, which
provide additional release data specific to air and surface water, respectively. NEI provides
comprehensive and detailed estimates of air emissions for criteria pollutants, criteria precursors and
Hazardous Air Pollutants (HAPs) on a 3-year cycle. Recent methylene chloride air emissions data from
NEI will be analyzed for point and non-point sources in the next phase of risk evaluation. The DMR
loading tool calculates pollutant loadings from permit and DMR data from EPA's Integrated Compliance
Information System for the National Pollutant Discharge Elimination System (ICIS-NPDES). DMR data
are available for the years 2007 to present and will be analyzed in the problem formulation phase of
risk evaluation.
2.3.3 Presence in the Environment and Biota
Monitoring studies or a collection of relevant and reliable monitoring studies provide(s) information
that can be used in an exposure assessment. Monitoring studies that measure environmental
concentrations or concentrations of chemical substances in biota provide evidence of exposure.
Monitoring and biomonitoring data were identified in EPA's data search for methylene chloride. Due to
its variety of uses and subsequent release to the environment, methylene chloride is present and
measurable through monitoring in a variety of environmental media including ambient and indoor air,
surface water and ground water, including sources used for drinking water supplies, sediment, soil and
food products.
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Ambient air samples worldwide have shown measured levels of methylene chloride, with background
levels usually around 50 parts per trillion (ATSDR. 2000). National Oceanic and Atmospheric
Administration (NOAA) monitoring data between 1994 and 2016 show mid-latitude northern
hemisphere atmospheric concentrations to decrease slightly from 1994 to the early 2000s, and then
increase thereafter to present day, with monthly mean concentrations ranging from approximately
30-80 parts per trillion (Hossaini et al., 2015). Similarly, air concentrations in the continental U.S.
between 2003 and 2014 showed either no trend or increasing levels of methylene chloride (U.S. EPA.
2016b). While available indoor air measurements for methylene chloride are less prevalent, it may be
present in this environment due to its variety of uses including consumer uses.
Methylene chloride has been detected in ground water and surface water, including finished drinking
water through varied national monitoring efforts and water quality databases such as U.S. EPA's
STOrage and RETrieval and Water Quality exchange (STORET) and U.S. Geological Survey's National
Water Quality Assessment Program (NAWQA) (U.S. EPA. 2009; ATSDR, 2000). As part of its 6-year
review of drinking water regulations, U.S. EPA (U.S. EPA. 2009) compiled a nationwide dataset of over
372,000 samples of ground water and surface water used for drinking water. Methylene chloride was
detected approximately 1% of the time, with median concentrations similar for ground water and
surface water. Other monitoring efforts have shown that with volatilization being limited in a ground
water environment and the ability of methylene chloride to readily transport to ground water,
concentrations are often higher in ground water as compared to surface water. Data compiled
between 1992 and 2001 from NAWQA showed methylene chloride to be found in 6% of all ground
water and surface water samples, with occurrences more common in surface water (U.S. EPA. 2009).
Methylene chloride was detected in 20% of sediment samples in the STORET database (ATSDR. 2000).
Methylene chloride and its metabolites have been measured in expired air, blood, urine and breast
milk (ATSDR. 2000). Elimination of methylene chloride from the body is rapid and therefore, is only
representative of recent exposures. Blood concentrations of methylene chloride were below the level
of detection in 1,165 individuals who participated in the National Health and Nutrition Examination
Survey (NHANES) 2003-2004 subsample of the U.S. population (CDC, 2009). The methylene chloride
metabolite, carboxyhemoglobin (COHb), has also been measured in blood and used as a biomarker;
however, COHb results from exposure to carbon monoxide (such as in tobacco smoke and automobile
exhaust) and is not specific to methylene chloride (ATSDR. 2000).
2.3.4 Environmental Exposures
The manufacturing, processing, distribution, use and disposal of methylene chloride can result in
releases to the environment. EPA expects to consider exposures to the environment and ecological
receptors that occur via the exposure pathways or media shown in Figure 2-4 in conducting the risk
evaluation for methylene chloride.
2.3.5 Human Exposures
EPA expects to consider three broad categories of human exposures: occupational exposures,
consumer exposures and general population exposures. Subpopulations within these exposure
categories will also be considered as described herein.
2.3.5.1 Occupational Exposures
EPA expects to consider worker activities where there is a potential for exposure under the various
conditions of use described in section 2.2. In addition, EPA expects to consider exposure to
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occupational non-users, who do not directly handle the chemical but perform work in an area where
the chemical is present. When data and information are available to support the analysis, EPA also
expects to consider the effect(s) that engineering controls and/or personal protective equipment have
on occupational exposure levels.
In the previous 2014 risk evaluation (U.S. EPA. 2014a). EPA assessed inhalation exposures to methylene
chloride for occupational use in paint and coating removal, which will not be re-evaluated. During this
scoping, additional uses were identified and described in section 2.2. The additional uses resulting in
occupational exposures will be considered during the risk evaluation.
Workers and occupational non-users may be exposed to methylene chloride when performing
activities associated with the conditions of use described in section 2.2, that may include:
• Unloading and transferring methylene chloride to and from storage containers to process
vessels;
• Using methylene chloride in process equipment (e.g., vapor degreasing machine, process
equipment used to manufacture refrigerants);
• Applying formulations and products containing methylene chloride onto substrates (e.g.,
applying paint removers containing methylene chloride onto painted substrates);
• Cleaning and maintaining equipment;
• Sampling chemical, formulations or products containing methylene chloride for quality control
(QC);
• Repackaging chemical, formulations or products containing methylene chloride;
• Handling, transporting and disposing waste containing methylene chloride;
• Performing other work activities in or near areas where methylene chloride is used.
Based on these activities, EPA expects to consider inhalation exposure to vapor and mists and
anticipates these are the most important methylene chloride exposure pathway for workers and
occupational non-users based on the high volatility of methylene chloride and the potential for spray
application of some products containing methylene chloride. Dermal exposure, including skin contact
with liquids and vapors for workers and occupational non-users may also be significant when
performing certain work activities. EPA also expects to consider potential worker exposure through
mists that deposit in the upper respiratory tract and are swallowed.
The United States has several regulatory and non-regulatory exposure limits for methylene chloride: an
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) of 25 ppm
8-hour time-weighted average (TWA) and Short-Term Exposure Limit (STEL) of 125 ppm 15-minute
TWA (OSHA, 1997). and an American Conference of Government Industrial Hygienists (ACGIH)
Threshold Limit Value (TLV) of 50 ppm 8-hour TWA (ACGIH. 2001). Also, the National Institute for
Occupational Safety and Health (NIOSH) indicates that methylene chloride has an immediately
dangerous to life and health (IDLH) value of 2,300 ppm based on effects that might occur from a
30-minute exposure, and NIOSH provides a notation that methylene chloride is a potential
occupational carcinogen (NIOSH. 2011).
Key data that inform occupational exposure assessment and which EPA expects to consider include:
the OSHA Chemical Exposure Health Data (CEHD) and NIOSH Health Hazard Evaluation (HHE) program
data. OSHA data are workplace monitoring data from OSHA inspections. The inspections can be
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random or targeted, or can be the result of a worker complaint. OSHA data can be obtained through
the OSHA Integrated Management Information System (IMIS) at https://www.osha.gov/oshstats/
index.html. Table_Apx B-l in Appendix B provides a summary of industry sectors with methylene
chloride personal monitoring air samples obtained from OSHA inspections conducted between 2011
and 2016. NIOSH HHEs are conducted at the request of employees, union officials, or employers and
help inform potential hazards at the workplace. HHEs can be downloaded at https://www.cdc.gov/
niosh/hhe/. During the problem formulation, EPA will review these data and evaluate their utility in the
risk evaluation.
2.3.5.2 Consumer Exposures
Methylene chloride can be found in consumer products and/or commercial products that are readily
available for public purchase at common retailers (EPA-HQ-OIF 03. Sections 3 and 4
and Table 2-3) and can therefore result in exposures to consumers.
Exposure routes for consumers using methylene chloride-containing products may include inhalation
of vapors, mists and aerosols (e.g., aerosols from spray applications), dermal exposure to products and
oral exposure to mists that deposit in the upper respiratory tract and are swallowed. Although unlikely
given the physical-chemical properties, EPA also expects to consider oral ingestion via oral route such
as from incidental ingestion of methylene chloride residue on hands and body.
In EPA's 2014 risk evaluation for methylene chloride paint stripping use, consumer inhalation
exposures in residential settings were assessed using a variety of indoor exposure scenarios (U.S. EPA.
2014a). Scenarios differed in their type of application (i.e., brush vs. spray), location of product
application (workshop vs. bathroom), mass of methylene chloride emitted, user's location during the
wait period and air exchange rate between the rest of the house with outdoor air. EPA will not reassess
those uses, but expects to develop exposure scenarios using similar approaches.
EPA expects to consider inhalation, dermal and oral exposures to consumers and bystanders associated
with the consumer use in the home.
2.3.5.3 General Population Exposures
Wastewater/liquid wastes, solid wastes or air emissions of methylene chloride could result in potential
pathways for oral, dermal or inhalation exposure to the general population. EPA will consider each
media, route and pathway to estimate general population exposures.
Inhalation
Inhalation serves as the expected primary route of exposure for the general population due to both its
high volatility and propensity to be released to air from ongoing commercial and industrial activities
(U.S. EPA, 2014a, 2009; ATSDR, 2000). Between 1998 and 2006, >90% of all reported TRI releases of
methylene chloride were air releases (U.S. EPA. 2014a) and levels of methylene chloride in the ambient
air are widespread and shown to be increasing (section 2.3.2).
Based on these potential sources and pathways of exposure, EPA expects to consider inhalation
exposures of the general population to methylene chloride in air that may result from the conditions of
use for methylene chloride.
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Oral
The general population may ingest methylene chloride via contaminated drinking water, ground water,
and/or surface water. Ingestion of drinking water is expected to be the primary route of oral exposure.
Oral ingestion may include exposure to contaminated breast milk. EPA also expects to consider
ingestion via the oral route such as from incidental ingestion of methylene chloride residue on the
hand/body. Based on the presence of methylene chloride in water used for bathing or recreation, the
oral ingestion of contaminated water could contribute, to a lesser degree, to oral exposures.
Methylene chloride has been measured in oysters and clams (ATSDR, 2000). however EPA does not
anticipate this to be a significant general population exposure pathway for methylene chloride based
on the low bioaccumulation potential in aquatic organisms (BCF 2.0 - 40, see the fate and transport
section 2.3.1).
Based on these potential sources and pathways of exposure, EPA expects to consider oral exposures to
the general population that may result from the conditions of use for methylene chloride.
Dermal
General population exposures to methylene chloride through the dermal route may occur through
contact with water such as while bathing in household water that has residual methylene chloride or
public recreation in contaminated waterways. Methylene chloride can be absorbed through the skin;
however, based on its physical and chemical properties once exposed to air most of the amount on
skin would be expected to volatize before being absorbed. EPA's previous risk evaluation of methylene
chloride used in paint removal focused on inhalation as the main exposure pathway. In that
assessment, not including dermal exposures may have resulted in underestimating the total exposure
to methylene chloride and this was described as an uncertainty of the assessment (U.S. EPA. 2014a).
Based on these potential sources and pathways of exposure, EPA expects to consider dermal exposures
to the general population that may result from the conditions of use for methylene chloride.
2.3.5.4 Potentially Exposed or Susceptible Subpopulations
TSCA requires that the determination of whether a chemical substance presents an unreasonable risk
include consideration of unreasonable risk to "a potentially exposed or susceptible subpopulation
identified as relevant to the risk evaluation" by EPA. TSCA § 3(12) states that "the term 'potentially
exposed or susceptible subpopulation' means a group of individuals within the general population
identified by the Administrator who, due to either greater susceptibility or greater exposure, may be at
greater risk than the general population of adverse health effects from exposure to a chemical
substance or mixture, such as infants, children, pregnant women, workers, or the elderly."
In this section, EPA addresses the potentially exposed or susceptible subpopulations identified as
relevant based on greater exposure. EPA will address the subpopulations identified as relevant based
on greater susceptibility in the hazard section.
Of the human receptors identified in the previous sections, EPA identifies the following as potentially
exposed or susceptible subpopulations due to their greater exposure that EPA expects to consider in
the risk evaluation:
• Workers and occupational bystanders including women of childbearing age.
• Consumers and bystanders associated with consumer use. Methylene chloride has been
identified as being used in products available to consumers; however, only some individuals
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within the general population may use these products. Therefore, those who do use these
products are a potentially exposed or susceptible subpopulation due to greater exposure.
• Other groups of individuals within the general population who may experience greater
exposures due to their proximity to conditions of use identified in section 2.2 that result in
releases to the environment and subsequent exposures (e.g., individuals who live or work near
manufacturing, processing, use or disposal sites).
In developing exposure scenarios, EPA will evaluate available data to ascertain whether some human
receptor groups may be exposed via exposure pathways that may be distinct to a particular
subpopulation or lifestage (e.g., children's crawling, mouthing or hand-to-mouth behaviors) and
whether some human receptor groups may have higher exposure via identified pathways of exposure
due to unique characteristics (e.g., activities, duration or location of exposure) when compared with
the general population (U.S. EPA. 2006a).
In summary, in the risk evaluation for methylene chloride, EPA expects to consider the following
potentially exposed groups of human receptors: workers, occupational non-users, consumers,
bystanders associated with consumer use. As described above, EPA may also identify additional
potentially exposed or susceptible subpopulations that will be considered based on greater exposure.
2.4 Hazards (Effects)
For scoping, EPA conducted comprehensive searches for data on hazards of methylene chloride, as
described in Strategy for Conducting Literature Searches for Methylene Chloride: Supplemental File for
the TSCA Scope Document. Based on initial screening, EPA expects to consider the hazards of
methylene chloride identified in this scope document. However, when conducting the risk evaluation,
the relevance of each hazard within the context of a specific exposure scenario will be judged for
appropriateness. For example, hazards that occur only as a result of chronic exposures may not be
applicable for acute exposure scenarios. This means that it is unlikely that every hazard identified in
the scope will be considered for every exposure scenario.
2,4,1 Environmental Hazards
For scoping purposes, EPA consulted the following sources of environmental hazard data for
methylene chloride: EPA's 2014 TSCA Work Plan Chemical Risk Assessment (U.S. EPA. 2014a), Canadian
. 1 i lority Substai * s (H _ > n in V * t
(SiAP) (QECD, 2011) and World Health Organization (WHQ)'s 1996 INCHEM Environmental Health
Criteria (EHC) 164 (WHO. 1996). However, EPA also expects to consider other studies (e.g., more
recently published, alternative test data) that have been published since these reviews, as identified in
the literature search conducted by the Agency for methylene chloride (Methylene Chloride (CASRN
75-09-2) Bibliography: Supplemental File for the TSCA Scope Document).
For U.S. EPA (2014a) risk evaluation, EPA reviewed acute and chronic (mortality and growth) toxicity
data for fish, aquatic invertebrates (immobilization), and aquatic plants. EPA did not assess the risks of
environmental effects from methylene chloride in their 2014 risk evaluation based on the selected uses
reviewed, expected concentrations of methylene chloride in the aquatic environment, methylene
chloride's physical and chemical properties, environmental fate characteristics and low aquatic toxicity
characterization.
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The Health Canada (1993) Priority Substances List Assessment Report suggested hazard to the
environment. In the Canadian report, there was acute and chronic (mortality, growth and
teratogenicity) toxicity in fish and acute toxicity (immobilization and teratogenicity) reported in aquatic
invertebrates. Mortality was observed in terrestrial invertebrates and amphibians, and effects (growth
inhibition or enhancement) were reported on seed germination in terrestrial plants.
The WHO (1996) International Programme on Chemical Safety (INCHEM) EHC on methylene chloride
indicated no significant impact to the environment. The EHC reported acute and chronic toxicity to fish,
acute toxicity to aquatic invertebrates and toxicity (cell number, photosynthesis) to aquatic plants.
Growth inhibition in terrestrial plants and mortality in soil invertebrates, birds, insects and amphibians
were also observed.
The OECD (2011) Screening Information Data Set (SIDS) SIAP for methylene chloride suggests a hazard
for the environment. The SIAP reported acute and chronic effects (mortality, growth and
teratogenicity) in fish, acute toxicity (immobilization) in aquatic invertebrates and toxicity to aquatic
plants that were briefly exposed to methylene chloride.
EPA expects to consider the hazards of methylene chloride to aquatic species including fish, aquatic
invertebrates and aquatic plants exposed to relevant media under acute and chronic exposure
conditions. EPA expects to consider the hazards of methylene chloride to terrestrial organisms
including soil invertebrates, birds, insects and mammals and amphibians exposed to relevant media
under acute and/or chronic exposure conditions.
2.4.2 Human Health Hazards
Methylene chloride has an existing EPA IRIS Assessment (U.S. EPA. 2011). an ATSDR Toxicological
Profile (ATSDR. 2010, 2000), and assessments of the effects of acute exposures in the AEGL (NAC/AEGL.
2008), Spacecraft Maximum Allowable Concentrations (SMAC) for Methylene Chloride (NRC. 1996) and
an acute Recommended Exposure Limit (REL) published by the Office of Environmental Health Hazard
Assessment (OEHHA) (OEHHA, 2008); hence, many of the hazards of methylene chloride have been
previously compiled and systematically reviewed. EPA has relied heavily on these comprehensive
reviews in preparing this scope. EPA also expects to consider other studies (e.g., more recently
published, alternative test data) that have been published since these reviews, as identified in the
literature search conducted by the Agency for methylene chloride (Methylene Chloride (CASRN
75-09-2) Bibliography: Supplemental File for the TSCA Scope Document). EPA expects to consider all
potential hazards associated with methylene chloride. Based on reasonably available information, the
following are the hazards that have been identified in previous government documents and that EPA
currently expects will likely be the focus of its analysis.
2.4.2.1 Non-Cancer Hazards
Acute Toxicity
Neurotoxicity indicative of CNS depression is a primary effect of methylene chloride in humans
following acute oral and inhalation exposures (U.S. EPA. 2011). Identified CNS depressive symptoms
include drowsiness, confusion, headache, dizziness and neurobehavioral deficits when performing
various tasks. Acute and/or short-term inhalation and oral exposure by animals to methylene chloride
has also resulted in CNS depressant effects; decreased motor activity; impaired learning and memory;
and changes in responses to sensory stimuli. CNS depressant effects can result in loss of consciousness
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and respiratory depression, resulting in irreversible coma, hypoxia and eventual death
2008).
Liver Toxicity
The liver is a sensitive target organ after inhalation and oral exposure (U.S. EPA, 2011). There is limited
evidence of liver effects in workers. Following chronic repeated inhalation and oral exposures to
methylene chloride, rats and mice exhibited hepatocyte vacuolation, necrosis and degeneration (U.S.
EPA. 2011).
Neurotoxicity
The brain is often affected by exposures to methylene chloride (U.S. EPA. 2011). As noted above, acute
non-lethal effects in humans include general CNS depressive symptoms. There is some limited
evidence of increased prevalence of neurological symptoms among workers and possible detriments in
attention and reaction time in complex tasks in retired workers after longer-term exposures (U.S. EPA.
2011).
Irritation
Following exposures to methylene chloride vapors, irritation has been observed in the respiratory tract
and eyes (ATSDR, 2000). Direct contact with liquid methylene chloride on the skin has caused chemical
burns in workers and gastrointestinal irritation in individuals who ingested methylene chloride (U.S.
EPA. 2011: ATSDR. 2000).
2.4.2.2 Genotoxicity and Cancer Hazards
Methylene chloride and some of its key metabolites have been extensively evaluated in
carcinogenicity, genotoxicity and other MOA studies. Most of these studies have been thoroughly
reviewed in the EPA IRIS Assessment (U.S. EPA. 2011). Studies in humans provide evidence for an
association between occupational exposure to methylene chloride and increased risk for some specific
cancers, including brain cancer, liver cancer, non-Hodgkin's lymphoma and multiple myeloma (U.S.
EPA. 2011). In addition, several cancer bioassays in animals have identified the liver and lung as the
most sensitive target organs for methylene chloride-induced tumor development (U.S. EPA, 2011). EPA
hypothesized that methylene chloride induced lung and liver tumors through a mutagenic mode of
carcinogenic action. A weight-of-evidence analysis of in vivo and in vitro data provide support to the
proposed mutagenicity of methylene chloride (U.S. EPA. 2011).
In the 2011 IRIS assessment, following U.S. EPA (2005) Guidelines for Carcinogen Risk Assessment U.S.
EPA (2005) using a weight-of-evidence judgment of the likelihood that methylene chloride is a human
carcinogen, EPA concluded that methylene chloride is "likely to be carcinogenic in humans by all routes
of exposure" and calculated quantitative estimates of risk from oral and inhalation exposure (U.S. EPA.
2011).
2.4.2.3 Potentially Exposed or Susceptible Subpopulations
TSCA requires that the determination of whether a chemical substance presents an unreasonable risk
include consideration of unreasonable risk to "a potentially exposed or susceptible subpopulation
identified as relevant to the risk evaluation" by EPA. TSCA § 3(12) states that "the term 'potentially
exposed or susceptible subpopulation' means a group of individuals within the general population
identified by the Administrator who, due to either greater susceptibility or greater exposure, may be at
greater risk than the general population of adverse health effects from exposure to a chemical
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substance or mixture, such as infants, children, pregnant women, workers, or the elderly." In
developing the hazard assessment, EPA will evaluate available data to ascertain whether some human
receptor groups may have greater susceptibility than the general population to the chemical's
hazard(s).
The IRIS assessment for methylene chloride indicates that there is some evidence that certain
populations may be more susceptible to exposure to methylene chloride and examined lifestage,
gender-specific, genetic variation, preexisting health status, lifestyle factors and nutrition status factors
(U.S. EPA. 2011). Genetic polymorphisms that impact the enzymes that metabolize methylene chloride
may lead to differences in susceptibility of individuals to the effects of methylene chloride and this
susceptibility was quantified by (U.S. EPA. 2011). There are inadequate chemical-specific data to
quantify the degree of differential susceptibility due to other susceptibility factors.
2.5 Initial Conceptual Models
A conceptual model describes the actual or predicted relationships between the chemical substance
and receptors, either human or environmental. These conceptual models are integrated depictions of
the conditions of use, exposures (pathways and routes), hazards and receptors. As part of the scope for
methylene chloride, EPA developed three conceptual models, presented here.
2.5.1 Initial Conceptual Model for Industrial and Commercial Activities and Uses:
Potential Exposures and Hazards
Figure 2-2 presents the initial conceptual model for human receptors from industrial and commercial
activities and uses of methylene chloride. EPA expects that workers and occupational non-users may
be exposed to methylene chloride via inhalation and dermal routes. In the U.S. EPA (2014a) risk
assessment, inhalation exposures to vapor were assessed as the most likely exposure route; however,
there are potential dermal exposures for some conditions of use, such as maintenance of industrial
degreasing tanks. EPA also expects to consider potential worker exposure through mists that deposit in
the upper respiratory tract and are swallowed. The pathways assessed in the U.S. EPA (2014a) risk
assessment are shaded in green.
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INDUSTRIAL AND COMMERCIAL EXPOSURE PATHWAY EXPOSURE ROUTE RECEPTORSe HAZARDS
ACTIVITIES / USES
Manufacturing
Processing:
• As Reactant
• Incorporated into
Formulation, Mixture, or
Reaction Product
• Repackaging
Recycling
Solvents for Cleaning or
Degreasing
Adhesives and Sealants
Paints and Coatings
including Paints and
Coatings Removersa
Metal Products
Fabric, Textile, and Leather
Products
Automotive Care Products
Apparel and Footwear Care
Products
Laundry and Dishwashing
Products
Lubricants and Greases
Other Usesb
Workersf,
Occupational
Non-Users
Wastewater, Liquid Wastes and Solid Wastes
(See Figure 2-4)
Pathway(s) assessed in U.S. EPA (2014a). See footnote a.
Fugitive
Emissions'1
Stack
Emissions1
Liquid Contact
"~ Liquid Contact, Vapor
Dermal
Air Pollution Control
Inhalationd
Vapor/ Mist
Dermal, Inhalation
Waste Handling,
Treatment and Disposal
Outdoor Air
(See Figure 2-4 for
Emissions to Air)
Workersf,
Occupational
Non-Users
Hazards Potentially Associated
with Acute and/or Chronic
Exposures:
See Section 2.4.2
Figure 2-2. Initial Methylene Chloride Conceptual Model for Industrial and Commercial Activities and Uses: Potential Exposures and
Hazards
The conceptual model presents the exposure pathways, exposure routes and hazards to human receptors from industrial and commercial
activities and uses of methylene chloride.
a U.S. EPA (2014a) assessed paint removal uses in industrial and commercial settings and therefore those uses are out of scope for the risk evaluation.
bSome products are used in both commercial and consumer applications such adhesives and sealants. Additional uses of methylene chloride are included in Table 2-3.
c Stack air emissions are emissions that occur through stacks, confined vents, ducts, pipes or other confined air streams. Fugitive air emissions are those that are not
stack emissions and include fugitive equipment leaks from valves, pump seals, flanges, compressors, sampling connections and open-ended lines; evaporative losses
from surface impoundment and spills; and releases from building ventilation systems.
d Exposure may occur through mists that deposit in the upper respiratory tract and are swallowed.
e Receptors include potentially exposed or susceptible subpopulations.
f When data and information are available to support the analysis, EPA also considers the effect that engineering controls and/or personal protective equipment have
on occupational exposure levels.
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2,5,2 Initial Conceptual Model for Consumer Activities and Uses: Potential
Exposures and Hazards
Figure 2-3 presents the initial conceptual model for human receptors from consumer uses of
methylene chloride. Similar to Figure 2-2, EPA expects that consumers and bystanders may be exposed
via inhalation, dermal and oral routes. In the U.S. EPA (2014a) risk assessment, inhalation exposures to
vapor and mist were assessed as the most likely exposure route; however, there are potential dermal
and oral exposures for some conditions of use. It should be noted that some consumers may purchase
and use products primarily intended for commercial use. It also shows emissions of methylene chloride
to wastewater, liquid and solid wastes containing methylene chloride.
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CONSUMER ACTIVITIES / USES EXPOSURE PATHWAY EXPOSURE ROUTE RECEPTORSd HAZARDS
Solvents for Cleaning or
Degreasing
Adhesives and Sealants
Paints and Coatings
including Paints and
Coatings Removersa
Metal Products
Consumers,
Bystanders
Fabric, Textile, and Leather
Products
Automotive Care Products
Apparel and Footwear Care
Products
Laundry and Dishwashing
Products
Lubricants and Greases
Other Usesb
Consumers,
Bystanders
Wastewater, Liquid Wastes and Solid Wastes
(See Figure 2-4)
Pathway(s) assessed in U.S. EPA (2014a). See footnote a.
Dermal
Liquid Contact
-~ Liquid Contact, Vapor
Vapor/ Mist
Inhalation
Dermal, Oral,
nhalation
Consumer Handling of
Disposal and Waste
Hazards Potentially
Associated with Acute
and/or Chronic
Exposures:
See Section 2.4.2
Figure 2-3. Initial Methylene Chloride Conceptual Model for Consumer Activities and Uses: Potential Exposures and Hazards
The conceptual model presents the exposure pathways, exposure routes and hazards to human receptors from consumer activities and
uses of methylene chloride.
a U.S. EPA (2014a) assessed paint removal uses in consumer settings and therefore those uses are out of scope for the risk evaluation.
bSome products are used in both commercial and consumer applications. Additional uses of methylene chloride are included in Table 2-3.
c Exposure may occur through mists that deposit in the upper respiratory tract and are swallowed. Although unlikely given the physical-chemical properties, oral
exposure may occur from incidental ingestion of methylene chloride on hands and body.
d Receptors include potentially exposed or susceptible subpopulations.
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2,5,3 Initial Conceptual Model for Environmental Releases and Wastes: Potential
Exposures and Hazards
As shown in Figure 2-4, EPA anticipates that general populations living near industrial and commercial
facilities using methylene chloride may be exposed via inhalation of outdoor air. General populations
may also be exposed via the oral, dermal or inhalation routes to contaminated surface, ground and
drinking water. In addition, aquatic and terrestrial life may be exposed to methylene chloride-
contaminated water and soil. Exposures to ecological species from releases of methylene chloride to
environmental media and disposal of wastes containing methylene chloride are depicted in Figure 2-4.
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RELEASES AND WASTES FROM
INDUSTRIAL / COMMERCIAL /
CONSUMER USES
EXPOSURE PATHWAY
EXPOSURE ROUTE RECEPTORSe
HAZARDS
Direct
discharge
Water,
Sediment
Aquatic
Species
~
Indirect
discharge
Biosolids
General
Population
Ground
water
Soil
Waste Transport
Air
Terrestrial
Species
Emissions to Air
POTW
Wastewater or
Liquid Wastesa
Off-site Waste
Transfer
Underground
Injection
Recycling, Other
Treatmentb
Oral
Dermal, Inhalation
Inhalationd
Liquid Wastes
Solid Wastes
Incinerators
(Municipal &
Hazardous Waste)
Industrial Pre-
Treatmentor
Industrial WWT
Municipal,
Hazardous Landfill
or Other Land
Disposal
Hazards Potentially Associated with
Acute and Chronic Exposures:
See Section 2.4.1
Hazards Potentially Associated with
Acute and Chronic Exposure:
See Section 2.4.1
Hazards Potentially Associated
with Acute and/or Chronic
Exposures:
See Section 2.4.2
] Human Health Pathway
j I Ecological Pathway
Figure 2-4. Initial Methylene Chloride Conceptual Model for Environmental Releases and Wastes: Potential Exposures and Hazards
The conceptual model presents the exposure pathways, exposure routes and hazards to human and environmental receptors from
environmental releases and wastes of methylene chloride.
a Industrial wastewater may be treated on-site and then released to surface water (direct discharge), or pre-treated and released to POTW (indirect discharge). For
consumer uses, wastewater may be released directly to POTW (i.e., down the drain). Drinking water will undergo further treatment in drinking water treatment plant.
Ground water may also be a source of drinking water.
b Additional releases may occur from recycling and other waste treatment.
c Volatilization from or liquid contact with tap water in the home during showering, bathing, washing, etc. represents another potential in-home exposure pathway.
d Presence of mist is not expected; dermal and oral exposures are negligible.
e Receptors include potentially exposed or susceptible subpopulations.
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2.6 Initial Analysis Plan
The initial analysis plan will be used to develop the eventual problem formulation and final analysis
plan for the risk evaluation. While EPA has conducted a search for readily available data and
information from public sources (see Methylene Chloride (CASRN 75-09-2) Bibliography: Supplemental
File for the TSCA Scope Document) as described in section 1.3, EPA encourages submission of additional
existing data, such as full study reports or workplace monitoring from industry sources, that may be
relevant for refining conditions of use, exposures, hazards and potentially exposed or susceptible
subpopulations.
The analysis plan outlined here is based on the conditions of use for methylene chloride, as described
in section 2.2 of this scope. The analysis plan may be refined as EPA proceeds with the systematic
review of the information in the Methylene Chloride (CASRN 75-09-2) Bibliography: Supplemental File
for the TSCA Scope Document. EPA will be evaluating the weight of the scientific evidence for both
hazard and exposure. Consistent with this approach, EPA will also use a systematic review approach. As
such, EPA will use explicit, pre-specified criteria and approaches to identify, select, assess, and
summarize the findings of studies. This approach will help to ensure that the review is complete,
unbiased, reproducible, and transparent.
2.6,1 Exposure
2.6.1.1 Environmental Releases
EPA expects to consider and analyze releases to environmental media as follows:
1) Review reasonably available published literature or information on processes and activities
associated with the conditions of use to evaluate the types of releases and wastes generated.
2) Review reasonably available chemical-specific release data, including measured or estimated
release data (e.g., data collected under the TRI and NEI programs).
3) Review reasonably available measured or estimated release data for surrogate chemicals that
have similar uses, volatility, chemical and physical properties.
4) Understand and consider regulatory limits that may inform estimation of environmental
releases.
5) Review and determine applicability of OECD Emission Scenario Documents (ESDs) and EPA
Generic Scenarios to estimation of environmental releases.
6) Evaluate the weight of the evidence of environmental release data.
7) Map or group each condition(s) of use to a release assessment scenario.
2.6.1.2 Environmental Fate
EPA expects to consider and analyze fate and transport in environmental media as follows:
1) Review reasonably available measured or estimated environmental fate endpoint data
collected through the literature search.
2) Using measured data and/or modeling, determine the influence of environmental fate
endpoints (e.g., persistence, bioaccumulation, partitioning, transport) on exposure pathways
and routes of exposure to human and environmental receptors.
3) Evaluate the weight of the evidence of environmental fate data.
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2.6.1.3 Environmental Exposures
EPA expects to consider the following in developing its environmental exposure assessment of
methylene chloride:
1) Review reasonably available environmental and biological monitoring data for all media
relevant to environmental exposure.
2) Review reasonably available information on releases to determine how modeled estimates of
concentrations near industrial point sources compare with available monitoring data. Available
exposure models will be evaluated and considered alongside available monitoring data to
characterize environmental exposures. Modeling approaches to estimate surface water
concentrations, sediment concentrations and soil concentrations generally consider the
following inputs: release into the media of interest, fate and transport and characteristics of the
environment.
3) Review reasonably available biomonitoring data. Consider whether these monitoring data could
be used to compare with species or taxa-specific toxicological benchmarks.
4) Determine applicability of existing additional contextualizing information for any monitored
data or modeled estimates during risk evaluation. Review and characterize the spatial and
temporal variability, to the extent that data are available, and characterize exposed aquatic and
terrestrial populations.
5) Evaluate the weight of evidence of environmental occurrence data and modeled estimates.
6) Map or group each condition(s) of use to environmental assessment scenario(s).
2.6.1.4 Occupational Exposures
EPA expects to consider and analyze both worker and occupational non-user exposures as follows:
1) Review reasonably available exposure monitoring data for specific condition(s) of use. Exposure
data to be reviewed may include workplace monitoring data collected by government agencies
such as OSHA and NIOSH, and monitoring data found in published literature (e.g., personal
exposure monitoring data (direct measurements) and area monitoring data (indirect
measurements).
2) Review reasonably available exposure data for surrogate chemicals that have uses, volatility
and chemical and physical properties similar to methylene chloride.
3) For conditions of use where data are limited or not available, review existing exposure models
that may be applicable in estimating exposure levels.
4) Review reasonably available data that may be used in developing, adapting or applying
exposure models to the particular risk evaluation.
5) Consider and incorporate applicable engineering controls and/or personal protective
equipment into exposure scenarios.
6) Evaluate the weight of the evidence of occupational exposure data.
7) Map or group each condition of use to occupational exposure assessment scenario(s).
2.6.1.5 Consumer Exposures
EPA expects to consider and analyze both consumers using a consumer product and bystanders
associated with the consumer using the product as follows:
1) Review reasonably available consumer product-specific exposure data related to consumer
uses/exposures.
2) Evaluate the weight of the evidence of consumer exposure data.
3) For exposure pathways where data are not available, review existing exposure models that may
be applicable in estimating exposure levels.
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4) Review reasonably available data that may be used in developing, adapting or applying
exposure models to the particular risk evaluation. For example, existing models developed for a
chemical assessment may be applicable to another chemical assessment if model parameter
data are available.
5) Review reasonably available consumer product-specific sources to determine how those
exposure estimates compare with those reported in monitoring data.
6) Review reasonably available population- or subpopulation-specific exposure factors and activity
patterns to determine if potentially exposed or susceptible subpopulations need be further
refined.
7) Map or group each condition of use to consumer exposure assessment scenario(s).
2.6.1.6 General Population
EPA expects to consider and analyze general population exposures as follows:
1) Review reasonably available environmental and biological monitoring data for media to which
general population exposures are expected.
2) For exposure pathways where data are not available, review existing exposure models that may
be applicable in estimating exposure levels.
3) Consider and incorporate applicable media-specific regulations into exposure scenarios or
modeling.
4) Review reasonably available data that may be used in developing, adapting or applying
exposure models to the particular risk evaluation. For example, existing models developed for a
chemical assessment may be applicable to another chemical assessment if model parameter
data are available.
5) Review reasonably available information on releases to determine how modeled estimates of
concentrations near industrial point sources compare with available monitoring data.
6) Review reasonably available population- or subpopulation-specific exposure factors and activity
patterns to determine if potentially exposed or susceptible subpopulations need be further
defined.
7) Evaluate the weight of the evidence of general population exposure data.
8) Map or group each condition of use to general population exposure assessment scenario(s).
2.6,2 Hazards (Effects)
2.6.2.1 Environmental Hazards
EPA will conduct an environmental hazard assessment of methylene chloride as follows:
1) Review reasonably available environmental hazard data, including data from alternative test
methods (e.g., computational toxicology and bioinformatics; high-throughput screening
methods; data on categories and read-across; in vitro studies).
2) Conduct hazard identification (the qualitative process of identifying acute and chronic
endpoints) and concentration-response assessment (the quantitative relationship between
hazard and exposure) for all identified environmental hazard endpoints.
3) Derive concentrations of concern (COC) for all identified ecological endpoints.
4) Evaluate the weight of the evidence of environmental hazard data.
5) Consider the route(s) of exposure, available biomonitoring data and available approaches to
integrate exposure and hazard assessments.
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2.6.2.2 Human Health Hazards
EPA expects to consider and analyze human health hazards as follows:
1) Review reasonably available human health hazard data, including data from alternative test
methods (e.g., computational toxicology and bioinformatics; high-throughput screening
methods; data on categories and read-across; in vitro studies; systems biology).
2) In evaluating reasonably available data, determine whether particular human receptor groups
may have greater susceptibility to the chemical's hazard(s) than the general population.
3) Conduct hazard identification (the qualitative process of identifying non-cancer and cancer
endpoints) and dose-response assessment (the quantitative relationship between hazard and
exposure) for all identified human health hazard endpoints.
4) Derive points of departure (PODs) where appropriate; conduct benchmark dose modeling
depending on the available data. Adjust the PODs as appropriate to conform (e.g., adjust for
duration of exposure) to the specific exposure scenarios evaluated.
5) Evaluate the weight of the evidence of human health hazard data.
6) Consider the route(s) of exposure (oral, inhalation, dermal), available route-to-route
extrapolation approaches, available biomonitoring data and available approaches to correlate
internal and external exposures to integrate exposure and hazard assessment.
2.63 Risk Characterization
Risk characterization is an integral component of the risk assessment process for both ecological and
human health risks. EPA will derive the risk characterization in accordance with EPA's Risk
Characterization Handbook (U.S. EPA. 2000b). As defined in EPA's Risk Characterization Policy, "the risk
characterization integrates information from the preceding components of the risk evaluation and
synthesizes an overall conclusion about risk that is complete, informative and useful for decision
makers." Risk characterization is considered to be a conscious and deliberate process to bring all
important considerations about risk, not only the likelihood of the risk but also the strengths and
limitations of the assessment, and a description of how others have assessed the risk into an
integrated picture.
Risk characterization at EPA assumes different levels of complexity depending on the nature of the risk
assessment being characterized. The level of information contained in each risk characterization varies
according to the type of assessment for which the characterization is written. Regardless of the level of
complexity or information, the risk characterization forTSCA risk evaluations will be prepared in a
manner that is transparent, clear, consistent, and reasonable (TCCR) (U.S. EPA. 2000b). EPA will also
present information in this section consistent with approaches described in the Risk Evaluation
Framework Rule.
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Protection Agency, Science Policy Council, https://www.epa.gov/risk/risk~characterization~
handbook
U.S. EPA (U.S. Environmental Protection Agency). (2005). Guidelines for Carcinogen Risk Assessment
[EPA Report] (pp. 1-166). (EPA/630/P-03/001F). Washington, DC: U.S. Environmental Protection
Agency, Risk Assessment Forum, http://www2.epa.gov/osa/guidelines-carcinogen~risk~
assessment
U.S. EPA (U.S. Environmental Protection Agency). (2006a). A Framework for Assessing Health Risk of
Environmental Exposures to Children (pp. 1-145). (EPA/600/R-05/093F). Washington, DC: U.S.
Environmental Protection Agency, Office of Research and Development, National Center for
Environmental Assessment. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=158363
U.S. EPA (U.S. Environmental Protection Agency). (2006b). Risk Assessment for the Halogenated
Solvent Cleaning Source Category [EPA Report]. (EPA Contract No. 68-D-01-052). Research
Triangle Park, NC: U.S. Environmental Protection Agency, Office of Air Quality Planning and
Standards, http://www3.epa.gov/airtoxics/degrea/residrisk2008.pdf
U.S. EPA (U.S. Environmental Protection Agency). (2009). Contaminant Occurrence Support Document
for Category 1 Contaminants for the Second Six-Year Review of National Primary Drinking
Water Regulations. (EPA-815-B-09-010).
U.S. EPA (U.S. Environmental Protection Agency). (2011). Toxicological Review of Dichloromethane
(Methylene Chloride) (CASRN 75-09-2) in Support of Summary Information on the Integrated
Risk Information System (IRIS) [EPA Report] (pp. 567). (EPA/635/R-10/003F). Washington, D.C.
http://www.epa.gov/iris/toxreviews/0070tr.pdf
U.S. EPA (U.S. Environmental Protection Agency). (2012). Estimation Programs Interface (Epi) Suite™
for Microsoft® Windows (Version 4.11). Washington D.C.: Environmental Protection Agency.
Retrieved from http://www.epa.gov/opptintr/exposure/pubs/episuite.htm
U.S. EPA (U.S. Environmental Protection Agency). (2014a). TSCA Work Plan Chemical Risk Assessment
Methylene Chloride: Paint Stripping Use CASRN: 75-09-2. (740-R1-4003). Office of Chemical
Safety and Pollution Prevention, https://www.epa.gov/sites/production/files/2015~
09/documents/dcm opptworkplanra final.pdf
U.S. EPA (U.S. Environmental Protection Agency). (2014b). TSCA Work Plan Chemical Risk Assessment.
Trichloroethylene: Degreasing, Spot Cleaning and Arts & Crafts Uses. In OCSPP. (EPA Document
#740-Rl-4002). Washington, DC: Office of Chemical Safety and Pollution Prevention.
Page 52 of 72
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http://www2.epa.gov/sites/production/files/2015~
09/documents/tce opptworkplanchemra final 062414.pdf
U.S. EPA (U.S. Environmental Protection Agency). (2015). Update of Human Health Ambient Water
Quality Criteria: Methylene Chloride 75-09-2. (EPA 820-R-15-057). Washington D.C.: Office of
Water, Office of Science and Technology.
https://www.federalregister.gov/documents/2014/05/13/2014~10963/updated~national~
recommended-water-quality-criteria-for-the-protection-of-human-health
U.S. EPA (U.S. Environmental Protection Agency). (2016a). Instructions for Reporting 2016 TSCA
Chemical Data Reporting, https://www.epa.gov/chemical~data~reporting/instructions-
reporting~2016~tsca~chemical~data~re porting
U.S. EPA (U.S. Environmental Protection Agency). (2016b). Our Nation's Air: Status and Trends through
2015. https://gispub.epa.gov/air/trendsreport/2016/
U.S. EPA (U.S. Environmental Protection Agency). (2016c). Public Database 2016 Chemical Data
Reporting (May 2017 Release). Washington, DC: US Environmental Protection Agency, Office of
Pollution Prevention and Toxics. Retrieved from https://www.epa.gov/chemical~data~reporting
U.S. EPA (U.S. Environmental Protection Agency). (2016d). TSCA Work Plan Chemical Risk Assessment:
Peer Review Draft 1-Bromopropane: (N-Propyl Bromide) Spray Adhesives, Dry Cleaning, and
Degreasing Uses CASRN: 106-94-5 [EPA Report], (EPA 740-R1-5001). Washington, DC.
https://www.epa.gov/sites/production/files/2016~03/documents/l~
bp report and appendices final.pdf
U.S. EPA (U.S. Environmental Protection Agency). (2017). Toxics Release Inventory (TRI). Retrieved
from https://www.epa.gov/toxics~release~inventorv-tri~program/tri~data~and~tools
WHO (World Health Organization). (1996). Methylene Chloride (Second Edition).
WHO (World Health Organization). (2000). Air Quality Guidelines for Europe (2nd ed.). Copenhagen,
Denmark: World Health Organization, Regional Office for Europe.
http://www.euro.who.int/en/health~topics/environment~and~health/air~
quality/publications/pre2009, ality-guidelines-for-europe
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APPENDICES
Appendix A REGULATORY HISTORY
A.l Federal Laws and Regulations
Table_Apx A-l. Federal Laws and Regulations
Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
EPA Regulations
TSCA - Section 6(a)
Provides EPA with the authority to
prohibit or limit the manufacture
(including import), processing,
distribution in commerce, use or
disposal of a chemical if EPA
evaluates the risk and concludes
that the chemical presents an
unreasonable risk to human
health or the environment.
Proposed rule (82 FR 7464)
regulating certain uses of
methylene chloride and
N-methylpyrrolidone in paint
and coating removal.
TSCA - Section 6(b)
EPA is directed to identify and
begin risk evaluations on
10 chemical substances drawn
from the 2014 update of the TSCA
Work Plan for Chemical
Assessments.
Methylene chloride is on the
initial list of chemicals to be
evaluated for unreasonable risk
under TSCA (81 FR 91927,
December 19, 2016).
TSCA - Section 8(a)
The TSCA section 8(a) CDR Rule
requires manufacturers (including
importers) to give EPA basic
exposure-related information on
the types, quantities and uses of
chemical substances produced
domestically and imported into
the United States.
Methylene chloride
manufacturing (including
importing), processing, and use
information is reported under
the CDR rule (76 FR 50816,
August 16, 2011).
TSCA - Section 8(b)
EPA must compile, keep current
and publish a list (the TSCA
Inventory) of each chemical
substance manufactured,
processed or imported in the
United States.
Methylene chloride was on the
initial TSCA Inventory and
therefore was not subject to
EPA's new chemicals review
process under TSCA section 5
(60 FR 16309, March 29, 1995).
TSCA - Section 8(d)
Provides EPA with authority to
issue rules requiring producers,
One submission received in
2001 (U.S. EPA, Chemical Data
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Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
importers, and (if specified)
processors of a chemical
substance or mixture to submit
lists and/or copies of health and
safety studies.
Access Tool. Accessed April 24,
2017).
TSCA - Section 8(e)
Manufacturers (including
importers), processors, and
distributors must immediately
notify EPA if they obtain
information that supports the
conclusion that a chemical
substance or mixture presents a
substantial risk of injury to health
or the environment.
Sixteen submissions received
1992-1994 (U.S. EPA,
ChemView. Accessed April 24,
2017).
TSCA - Section 4
Provides EPA with authority to
issue rules and orders requiring
manufacturers (including
importers) and processors to test
chemical substances and mixtures.
Five chemical data from test
rules (Section 4) from 1947 and
(U.S. EPA, ChemView. Accessed
April 24, 2017).
Emergency Planning and
Community Right-to-
Know Act (EPCRA) -
Section 313
Requires annual reporting from
facilities in specific industry
sectors that employ 10 or more
full-time equivalent employees
and that manufacture, process or
otherwise use a TRI-listed
chemical in quantities above
threshold levels.
Methylene chloride is a listed
substance subject to reporting
requirements under 40 CFR
372.65 effective as of January
01, 1987.
Federal Food, Drug, and
Cosmetic Act (FFDCA) -
Section 408
FFDCA governs the allowable
residues of pesticides in food.
Section 408 of the FFDCA provides
EPA with the authority to set
tolerances (rules that establish
maximum allowable residue
limits), or exemptions from the
requirement of a tolerance, for all
residues of a pesticide (including
both active and inert ingredients)
that are in or on food. Prior to
issuing a tolerance or exemption
from tolerance, EPA must
Methylene chloride was
registered as antimicrobial,
conventional chemical in 1974,
but this tolerance was revoked
in 2002, and there are currently
no registrations for use as a
pesticide (67 FR 16027, April 4,
2002).
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Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
determine that the tolerance or
exemption is "safe." Sections
408(b) and (c) of the FFDCA define
"safe" to mean the Agency has a
reasonable certainty that no harm
will result from aggregate
exposures to the pesticide
residue, including all dietary
exposure and all other exposure
(e.g., non-occupational exposures)
for which there is reliable
information. Pesticide tolerances
or exemptions from tolerance that
do not meet the FFDCA safety
standard are subject to
revocation. In the absence of a
tolerance or an exemption from
tolerance, a food containing a
pesticide residue is considered
adulterated and may not be
distributed in interstate
commerce.
Clean Air Act (CAA) -
Section 112(b)
Defines the original list of 189
HAPs. Under 112(c) of the CAA,
EPA must identify and list source
categories that emit HAP and then
set emission standards for those
listed source categories under CAA
section 112(d). CAA section
112(b)(3)(A) specifies that any
person may petition the
Administrator to modify the list of
HAP by adding or deleting a
substance. Since 1990, EPA has
removed two pollutants from the
original list leaving 187 at present.
Lists methylene chloride as a
HAP (42 U.S. Code section
7412), and is considered an
"urban air toxic" (CAA Section
112(k)).
CAA-Section 112(d)
Section 112(d) states that the EPA
must establish NESHAPs for each
category or subcategory of major
sources and area sources of HAPs
(listed pursuant to Section 112(c)).
There are a number of source-
specific NESHAPs for methylene
chloride, including:
• Foam production and
fabrication process (68 FR
Page 56 of 72
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Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
The standards must require the
18062, April 14, 2003; 72 FR
maximum degree of emission
38864, July 16, 20027; 73 FR
reduction that the EPA determines
15923, March 26, 2008; 79
to be achievable by each
FR 48073, August 15, 2014).
particular source category.
• Aerospace (60 FR 45948,
Different criteria for maximum
September 1, 1995).
achievable control technology
• Boat manufacturing (66FR
(MACT) apply for new and existing
44218, August 22, 2001).
sources. Less stringent standards,
• Chemical manufacturing
known as generally available
industry (agricultural
control technology (GACT)
chemicals and pesticides,
standards, are allowed at the
cyclic crude and
Administrator's discretion for area
intermediate production,
sources.
industrial inorganic
chemicals, industrial and
miscellaneous organic
chemicals, inorganic
pigments, plastic materials
and resins, pharmaceutical
production, synthetic
rubber) (74 FR 56008,
October 29, 2009).
• Fabric printing, coating and
dyeing (68 FR 32172, May
29, 2003).
• Halogenated Solvent
Cleaning (72 FR 25138, May
3, 2007).
• Miscellaneous organic
chemical production and
processes (MON) (68 FR
63852, November 10, 2003).
• Paint and allied products
manufacturing (area
sources) (74 FR 63504,
December 3, 2009).
• Paint stripping and
miscellaneous surface
coating operations (area
sources) (73 FR 1738,
January 9, 2008).
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Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
• Paper and other web
surface coating (67 FR
72330, December 4, 2002).
• Pesticide active ingredient
production (67 Fr 38200,
June 3, 2002).
• Pharmaceutical production
(63 FR 50280, September
21, 1998).
• Publicly Owned Treatment
Works (64 FR 57572,
October 26, 1999).
• Reciprocating Internal
Combustion Engines (RICE)
(75 FR 51570, August 20,
2010).
• Reinforced plastic
composites production (68
FR 19375, April 21, 2003).
• Wood preserving (area
sources) (72 FR 38864, July
16, 2007).)
CAA - Section 612
Under Section 612 of the CAA,
EPA's Significant New Alternatives
Policy (SNAP) program reviews
substitutes for ozone-depleting
substances within a comparative
risk framework. EPA publishes lists
of acceptable and unacceptable
alternatives. A determination that
an alternative is unacceptable, or
acceptable only with conditions, is
made through rulemaking.
Under the SNAP program, EPA
listed methylene chloride as an
acceptable substitute in
multiple industries, including in
foam blowing agents for
polyurethane, in cleaning
solvents, in aerosol solvents
and in adhesives and coatings
(59 FR, March 18 1994). In
2016, methylene chloride was
listed as an unacceptable
substitute for use in flexible
polyurethane (81 FR 86778
December 1, 2016).
Clean Water Act (CWA) -
Section 301(b), 304(b),
306, and 307(b)
Requires establishment of Effluent
Limitations Guidelines and
Standards for conventional, toxic,
and non-conventional pollutants.
For toxic and non-conventional
Methylene chloride is
designated as a toxic pollutant
under section 307(a)(1) of the
CWA and as such is subject to
effluent limitations. Also under
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Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
pollutants, EPA identifies the best
available technology that is
economically achievable for that
industry after considering
statutorily prescribed factors and
sets regulatory requirements
based on the performance of that
technology.
section 304, methylene
chloride is included in the list of
total toxic organics (TTO) (40
CFR413.02(i)).
CWA - Section 307(a)
Establishes a list of toxic
pollutants or combination of
pollutants under the CWA. The
statue specifies a list of families of
toxic pollutants also listed in the
Code of Federal Regulations at 40
CFR Part 401.15. The "priority
pollutants" specified by those
families are listed in 40 CFR Part
423 Appendix A. These are
pollutants for which best available
technology effluent limitations
must be established on either a
national basis through rules
(Sections 301(b), 304(b), 307(b),
306) or on a case-by-case best
professional judgement basis in
NPDES permits (Section
402(a)(1)(B)).
Safe Drinking Water Act
(SDWA) - Section 1412
Requires EPA to publish a non-
enforceable maximum
contaminant level goals (MCLGs)
for contaminants which 1. may
have an adverse effect on the
health of persons; 2. are known to
occur or there is a substantial
likelihood that the contaminant
will occur in public water systems
with a frequency and at levels of
public health concern; and 3. in
the sole judgement of the
Administrator, regulation of the
contaminant presents a
Methylene chloride is subject
to NPDWR under the SDWA
with a MCLG of zero and an
enforceable MCL of 0.005 mg/L
or 5 ppb (Section 1412).
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Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
meaningful opportunity for health
risk reductions for persons served
by public water systems. When
EPA publishes an MCLG, EPA must
also promulgate a National
Primary Drinking Water
Regulation (NPDWR) which
includes either an enforceable
maximum contaminant level
(MCL), or a required treatment
technique. Public water systems
are required to comply with
NPDWRs.
Comprehensive
Environmental Response,
Compensation and
Liability Act (CERCLA) -
Sections 102(a) and 103
Authorizes EPA to promulgate
regulations designating as
hazardous substances those
substances which, when released
into the environment, may
present substantial danger to the
public health or welfare or the
environment. EPA must also
promulgate regulations
establishing the quantity of any
hazardous substance the release
of which must be reported under
Section 103.
Section 103 requires persons in
charge of vessels or facilities to
report to the National Response
Center if they have knowledge of
a release of a hazardous
substance above the reportable
quantity threshold.
Methylene chloride is a
hazardous substance under
CERCLA. Releases of methylene
chloride in excess of 1,000
pounds must be reported (40
CFR 302.4).
Resource Conservation
and Recovery Act (RCRA)
- Section 3001
Directs EPA to develop and
promulgate criteria for identifying
the characteristics of hazardous
waste, and for listing hazardous
waste, taking into account toxicity,
persistence, and degradability in
nature, potential for accumulation
Methylene chloride is included
on the list of hazardous wastes
pursuant to RCRA 3001.
RCRA Hazardous Waste Code:
F001, F002; U080
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Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
in tissue and other related factors
such as flammability,
corrosiveness, and other
hazardous characteristics.
In 2013, EPA modified its
hazardous waste management
regulations to conditionally
exclude solvent-contaminated
wipes that have been cleaned
and reused from the definition
of solid waste under RCRA (78
FR 46447 July 31, 2013, 40 CFR
261.4(a)(26)).
Other Federal Regulations
Federal Hazardous
Substance Act (FHSA)
Requires precautionary labeling
on the immediate container of
hazardous household products
and allows the Consumer Product
Safety Commission (CPSC) to ban
certain products that are so
dangerous or the nature of the
hazard is such that required
labeling is not adequate to protect
consumers.
The CPSA, as implemented by
the CPSC, requires products
that contain methylene
chloride to be labelled (52 FR
34698, September 14,1987). In
2016, the Halogenated Solvents
Industry Alliance petitioned to
the CPSC to amend the labeling
requirement (81 FR 60298,
September 1, 2016).
Hazardous Materials
Transportation Act
(HMTA)
Section 5103 of the Act directs the
Secretary of Transportation to:
• Designate material (including
an explosive, radioactive
material, infectious substance,
flammable or combustible
liquid, solid or gas, toxic,
oxidizing or corrosive material,
and compressed gas) as
hazardous when the Secretary
determines that transporting
the material in commerce may
pose an unreasonable risk to
health and safety or property.
• Issue regulations for the safe
transportation, including
security, of hazardous material
in intrastate, interstate and
foreign commerce.
Methylene chloride is listed as
a hazardous material with
regard to transportation and
regulated by agencies
including the Pipeline and
Hazardous Materials Safety
Administration (PHMSA),
Department of Transportation
(DOT) and the U.S. Coast
Guard (70 FR 34381 June 14
2005).
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Statutes/Regulations
Description of
Authority/Regulation
Description of Regulation
Federal Food, Drug, and
Cosmetic Act (FFDCA)
Provides the FDA with authority to
oversee the safety of food, drugs
and cosmetics.
Methylene chloride is banned
by the FDA as an ingredient in
all cosmetic products (54 FR
27328, June 29, 1989).
Occupational Safety and
Health Act (OSH Act)
Requires employers to provide
their workers with a place of
employment free from recognized
hazards to safety and health, such
as exposure to toxic chemicals,
excessive noise levels, mechanical
dangers, heat or cold stress or
unsanitary conditions (29 U.S.C
section651 et seq.).
Under the Act, OSHA can issue
occupational safety and health
standards including such
provisions as PELs, exposure
monitoring, engineering and
administrative control measures,
and respiratory protection.
In 1997, OSHA revised an
existing occupational safety
and health standards for
methylene chloride, to include
a PEL of 25 ppmTWA,
exposure monitoring, control
measures and respiratory
protection (29 CFR 1910.1052
App. A).
A.2 State Laws and Regulations
Table_Apx A-2. State Laws and Regulations
State Actions
Description of Action
State PELs
California (PEL of 25 ppm and a STEL of 100) (Cal Code Regs, title 8,
section 5155)
State Right-to-
Know Acts
Massachusetts (454 Code Mass. Regs, section 21.00), New Jersey (8:59
N.J. Admin. Code section 9.1) and Pennsylvania (34 Pa. Code section 323).
State Drinking
Water Standards
and Guidelines
Arizona (14 Ariz. Admin. Register 2978, August 1, 2008), California (Cal
Code Regs. Title 26, section 22-64444), Delaware (Del. Admin. Code Title
16, section 4462), Connecticut (Conn. Agencies Regs, section 19-13-B102),
Florida (Fla. Admin. Code R. Chap. 62-550), Maine (10 144 Me. Code R.
Chap. 231), Massachusetts (310 Code Mass. Regs, section 22.00),
Minnesota (Minn R. Chap. 4720), New Jersey (7:10 N.J Admin. Code
section 5.2), Pennsylvania (25 Pa. Code section 109.202), Rhode Island (14
R.I. Code R. section 180-003), Texas (30 Tex. Admin. Code section
290.104).
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State Actions
Description of Action
Chemicals of High
Concern to
Children
Several states have adopted reporting laws for chemicals in children's
products that include methylene chloride, including Maine (38 MRSA
Chapter 16-D), Minnesota (Minnesota Statutes 116.9401 to 116.9407),
Oregon (Toxic-Free Kids Act, Senate Bill 478, 2015), Vermont (18 V.S.A
section 1776) and Washington State (WAC 173-334-130).
Volatile Organic
Compound (VOC)
Regulations for
Consumer
Products
Many states regulate methylene chloride as a VOC. These regulations may
set VOC limits for consumer products and/or ban the sale of certain
consumer products as an ingredient and/or impurity. Regulated products
vary from state to state, and could include contact and aerosol adhesives,
aerosols, electronic cleaners, footwear or leather care products and
general degreasers, among other products. California (Title 17, California
Code of Regulations, Division 3, Chapter 1, Subchapter 8.5, Articles 1, 2, 3
and 4), Connecticut (R.C.S.A Sections 22a-174-40, 22a-174-41, and 22a-
174-44), Delaware (Adm. Code Title 7,1141), District of Columbia (Rules
20-720, 20-721, 20-735, 20-736, 20-737), Illinois (35 Adm Code 223),
Indiana ( 326 IAC 8-15), Maine (Chapter 152 of the Maine Department of
Environmental Protection Regulations), Maryland (COMAR 26.11.32.00 to
26.11.32.26), Michigan (R 336.1660 and R 336. 1661), New Hampshire
(Env-A 4100) New Jersey (Title 7, Chapter 27, Subchapter 24), New York (6
CRR-NY III A 235), Rhode Island (Air Pollution Control Regulation No. 31)
and Virginia (9VAC5 CHAPTER 45) all have VOC regulations or limits for
consumer products. Some of these states also require emissions
reporting.
Other
California listed methylene chloride on Proposition 65 (Cal Code Regs, title
27, section 27001)
Massachusetts designated methylene chloride as a Higher Hazard
Substance which will require reporting starting in 2014 (301 CMR 41.00).
A.3 International Laws and Regulations
Table_Apx A-3. Regulatory Actions by Other Governments and Tribes
Country/
Organization
Requirements and Restrictions
Canada
Methylene chloride is on the Canadian List of Toxic Substances (CEPA
1999 Schedule 1). Canada required pollution prevention plan
implementation for methylene chloride in 2003 for aircraft paint
stripping; flexible polyurethane foam blowing; pharmaceuticals and
chemical intermediates manufacturing and tablet coating; industrial
cleaning; and adhesive formulations. The overall reduction objective of
85% was exceeded (Canada Gazette, Part 1, Saturday, February 28, 2004;
Vol. 138, No. 9, p. 409).
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Country/
Organization
Requirements and Restrictions
European Union
In 2010, a restriction of sale and use of paint removers containing 0.1%
or more methylene chloride was added to Annex XVII of regulation (EC)
No 1907/2006 - REACH (Registration, Evaluation, Authorization and
Restriction of Chemicals). The restriction included provisions for
individual member states to issue a derogation for professional uses if
they have completed proper training and demonstrate they are capable
of safely use the paint removers containing methylene chloride
(European Chemicals Agency (ECHA) database. Accessed April 18, 2017).
Australia
Methylene chloride was assessed under Human Health Tier II of the
Inventory Multi-Tiered Assessment and Prioritisation (IMAP). Uses
reported include solvent in paint removers, adhesives, detergents, print
developing, aerosol propellants (products not specified), cold tank
degreasing and metal cleaning, as well as uses in waterproof
membranes, in urethane foam and plastic manufacturing, and as an
extraction solvent for spices, caffeine and hops (NICNAS, 2017, Human
Health Tier II assessment for Methane, dichloro-. Accessed April, 18
2017J.
Japan
Methylene chloride is regulated in Japan under the following legislation:
Act on the Evaluation of Chemical Substances and Regulation of Their
Manufacture, etc. (Chemical Substances Control Law; CSCL)
• Act on Confirmation, etc. of Release Amounts of Specific
Chemical Substances in the Environment and Promotion of
Improvements to the Management Thereof
• Industrial Safety and Health Act (ISHA)
• Air Pollution Control Law
• Water Pollution Control Law
• Soil Contamination Countermeasures Act
(National Institute of Technology and Evaluation [NITE] Chemical Risk
Information Platform [CHIRP]. Accessed April 17, 2017).
Basel Convention
Halogenated organic solvents (Y41) are listed as a category of waste
under the Basel Convention. Although the United States is not currently
a party to the Basel Convention, this treaty still affects U.S. importers
and exporters.
OECD Control of
Transboundary
Movements of
Wastes Destined
for Recovery
Operations
Halogenated organic solvents (A3150) are listed as a category of waste
subject to The Amber Control Procedure under Council Decision C (2001)
107/Final.
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Country/
Organization
Requirements and Restrictions
Australia, Austria,
Occupational exposure limits for methylene chloride (GESTIS
Belgium, Canada,
International limit values for chemical agents (Occupational exposure
Denmark,
limits, OELs) database. Accessed April 18, 2017).
European Union,
Finland, France,
Germany,
Hungary, Ireland,
Israel, Japan,
Latvia New
Zealand, People's
Republic of China,
Poland, Singapore,
South Korea,
Spain, Sweden,
Switzerland,
United Kingdom
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Appendix B PROCESS, RELEASE AND OCCUPATIONAL EXPOSURE
INFORMATION
This appendix provides information and data found in preliminary data gathering for methylene
chloride.
B.l Process Information
Process-related information potentially relevant to the risk evaluation may include process diagrams,
descriptions and equipment. Such information may inform potential release sources and worker
exposure activities.
Note that the processing information below is representative of methylene chloride, but not inclusive
of all uses. EPA will consider this information and data in combination with other data and methods for
use in the risk evaluation.
B.l.l Manufacturing (Includes Import)
According to 2016 public CDR data, methylene chloride is both manufactured in and imported into the
United States (U.S. EPA. 2016c).
B.l.1.1 Domestic Manufacturing
Methylene chloride is primarily manufactured through the gas-phase reaction of hydrogen chloride
with methanol to produce methyl chloride, which is then reacted with chlorine to produce methylene
chloride, along with chloroform and carbon tetrachloride as coproducts. This reaction is typically driven
by high temperature, but may also be driven through catalysis or photolysis. This reaction may
alternatively be conducted in the liquid phase at low temperatures and high pressures, which can yield
high selectivities of methylene chloride (Holbrook, 2003).
An antiquated production method of methylene chloride is the reaction of excess methane with
chlorine at temperatures of approximately 400 to 500°C. Lower reaction temperatures are possible
through the use of catalysis or photolysis. This reaction produces methylene chloride with methyl
chloride, chloroform and carbon tetrachloride as coproducts and unreacted methane with hydrogen
chloride as byproducts. The unreacted methane and hydrogen chloride are removed through a water
wash, dried, and recycled. The liquid stream of chlorinated organic products is washed, alkali scrubbed,
dried and fractionated (Holbrook. 2003).
Other minor production methods of methylene chloride exist, such as: the reduction of chloroform or
carbon tetrachloride with hydrogen over a platinum catalyst; the molten salt oxychlorination of
methane; the reaction of phosgene and formaldehyde over an activated carbon catalyst; and the
reduction of carbon tetrachloride with ferrous hydroxide in the presence of alkaline hydroxides or
carbonates (Holbrook. 2003).
B.l.1.2 Import
Based on EPA's knowledge of the chemical industry, typical import activities include storage in
warehouses prior to distribution for further processing and use and QC sampling.
Methylene chloride may be transported in drums, trucks, railcars, barges and oceangoing ships.
Storage contains should be constructed of galvanized or otherwise suitably lined mild or plain steel.
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Bulk storage tanks should include a vent equipped with a desiccant-packed dryer, such as calcium
chloride, or an inert gas pad with pressure/vacuum relief valve (Holbrook. 2003).
B.1.2 Processing and Distribution
B.1.2.1 Processing as Reactant
Processing as a reactant or intermediate is the use of methylene chloride as a feedstock in the
production of another chemical product via a chemical reaction in which methylene chloride is
consumed to form the product. Methylene chloride is used as an intermediate for the production of
difluoromethane, also known as HFC-32, which is used in fluorocarbon blends for refrigerants
(Marshall, 2016).
Methylene chloride is also a feedstock in the production of bromochloromethane. Bromochloro-
methane is produced through a halogen exchange reaction with methylene chloride and either
bromine or hydrogen bromide with an aluminum or aluminum trihalide catalyst. Alternative processes
include the gas-phase bromination of methylene chloride with hydrogen bromide and the liquid-phase
displacement reaction of methylene chloride with inorganic bromides (loffe, 2011).
B.1.2.2 Incorporated into Formulation, Mixture, or Reaction Product
Incorporation into a formulation, mixture or reaction product refers to the process of mixing or
blending of several raw materials to obtain a single product or preparation. The uses of methylene
chloride that may require incorporation into a formulation include paint removers; adhesives and
sealants; paints and coatings; degreasers, cleaners, and spot removers; and lubricants. Methylene
chloride-specific formulation processes were not identified; however, several ESDs published by the
OECD have been identified that provide general process descriptions for some of these types of
products. The formulation of paints and coatings typically involves dispersion, milling, finishing and
filling into final packages (OECD, 2009b). Adhesive formulation involves mixing together volatile and
non-volatile chemical components in sealed, unsealed or heated processes (OECD, 2009a). Sealed
processes are most common for adhesive formulation because many adhesives are designed to set or
react when exposed to ambient conditions (OECD, 2009a). Lubricant formulation typically involves the
blending of two or more components, including liquid and solid additives, together in a blending vessel
(OECD. 2004).
B.1.2.3 Repackaging
Based on EPA's knowledge of the chemical industry, typical repackaging sites receive the chemical in
bulk containers and transfer the chemical from the bulk container into another smaller container in
preparation for distribution in commerce.
B.1.2.4 Recycling
TRI data from 2015 indicate that many sites ship methylene chloride for off-site recycling. A general
description of waste solvent recovery processes was identified. Waste solvents are generated when it
becomes contaminated with suspended and dissolved solids, organics, water, or other substance (U.S.
EPA. 1980). Waste solvents can be restored to a condition that permits reuse via solvent
reclamation/recycling (U.S. EPA. 1980). The recovery process involves an initial vapor recovery (e.g.,
condensation, adsorption, and absorption) or mechanical separation (e.g., decanting, filtering,
draining, setline, and centrifuging) step followed by distillation, purification, and final packaging (U.S.
EPA. 1980).
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B.1.3 Uses
In this scope document, EPA has grouped uses based on CDR categories and identified examples within
these categories as subcategories. Note that some subcategories may be grouped under multiple CDR
categories. The differences between these uses will be further investigated and defined during risk
evaluation.
B.1.3.1 Solvents for Cleaning or Degreasing
EPA has gathered information on different types of cleaning and degreasing systems from recent
trichloroethylene risk evaluation (U.S. EPA. 2014b) and risk management (82 FR 7432, January 19,
2017; 81 FR 91592, December 16, 2016) activities and 1-Bromopropane Draft Risk Assessment (U.S.
EPA. 2016d) activities. Provided below are descriptions of three cleaning and degreasing uses of
methylene chloride.
Vapor Degreasers
Vapor degreasing is a process used to remove dirt, grease and surface contaminants in a variety of
metal cleaning industries. Vapor degreasing may take place in batches or as part of an in-line (i.e.,
continuous) system. Vapor degreasing equipment can generally be categorized into one of three
degreaser types described below:
1) Batch vapor degreasers - In batch machines, each load (parts or baskets of parts) is loaded into
the machine after the previous load is completed. Individual organizations, regulations and
academic studies have classified batch vapor degreasers differently. For the purposes of the
scope document, EPA categories the batch vapor degreasers into five types: open-top vapor
degreasers (OTVDs); OTVDs with enclosures; closed-loop degreasing systems (airtight); airless
degreasing systems (vacuum drying); and airless vacuum-to-vacuum degreasing systems.
2) Conveyorized vapor degreasers - In conveyorized systems, an automated parts handling
system, typically a conveyor, continuously loads parts into and through the vapor degreasing
equipment and the subsequent drying steps. Conveyorized degreasing systems are usually fully
enclosed except for the conveyor inlet and outlet portals. Conveyorized degreasers are likely
used in shops where there are a large number of parts being cleaned. There are seven major
types of conveyorized degreasers: monorail degreasers; cross-rod degreasers; vibra degreasers;
ferris wheel degreasers; belt degreasers; strip degreasers; and circuit board degreasers (U.S.
EPA. 1977).
3) Continuous web vapor degreasers - Continuous web cleaning machines are a subset of in-line
degreasers but differ in that they are specifically designed for cleaning parts that are coiled or
on spools such as films, wires and metal strips (Kanegsberg and Kanegsberg. 2011: U.S. EPA.
2006b). In continuous web degreasers, parts are uncoiled and loaded onto rollers that transport
the parts through the cleaning and drying zones at speeds >11 feet/minute (U.S. EPA. 2006b).
The parts are then recoiled or cut after exiting the cleaning machine (Kanegsberg and
Kanegsberg. 2011: U.S. EPA. 2006b).
Cold Cleaners
Methylene chloride can also be used as a solvent in cold cleaners, which are non-boiling solvent
degreasing units. Cold cleaning operations include spraying, brushing, flushing and immersion; the use
process and worker activities associated with cold cleaning have been previously described in EPA's
1-Bromopropane Draft Risk Assessment (U.S. EPA. 2016d).
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Aerosol Spray Degreasers and Cleaners
Aerosol degreasing is a process that uses an aerosolized solvent spray, typically applied from a
pressurized can, to remove residual contaminants from fabricated parts. Products containing
methylene chloride may be used in aerosol degreasing applications such as brake cleaning, engine
degreasing and metal product cleaning (see the Preliminary Information on Manufacturing, Processing,
Distribution, Use and Disposal for Methylene Chloride EPA-HQ-QPPT-2016-0742-0003). This use has
been previously described in EPA's 1-Bromopropane Draft Risk Assessment (U.S. EPA, 2016d). Aerosol
degreasing may occur at either industrial facilities or at commercial repair shops to remove
contaminants on items being serviced. Aerosol degreasing products may also be purchased and used
by consumers for various applications.
B.l.3.2 Adhesives and Sealants
Based on products identified in EPA's Preliminary Information on Manufacturing, Processing,
Distribution, Use, and Disposal for Methylene Chloride L . - .... ... ) and 2016 CDR
reporting (U.S. EPA. 2016c), methylene chloride may be used in adhesives and sealants for industrial,
commercial and consumer applications. The Preliminary Information on Manufacturing, Processing,
Distribution, Use and Disposal for Methylene Chloride (EPA-HQ-QPPT-2016-0742-0003) identifies
aerosol and canister adhesive products that contain methylene chloride. In these applications, the
methylene chloride likely serves as a propellant or solvent and evaporates during adhesive drying.
These adhesive products are identified for use on substrates such as metal, foam, plastic, rubber,
fabric, leather, wood and fiberglass. The types of adhesives identified in the Preliminary Information on
Manufacturing, Processing, Distribution, Use and Disposal for Methylene Chloride (EPA-HQ-QPPT-2016-
0742-0003) include contact adhesives, crosslinking adhesives, pressure sensitive adhesives, sealers and
cements.
The OECD ESD for Use of Adhesives (OECD, 2013) provides general process descriptions and worker
activities for industrial adhesive uses. Given the identified applications of methylene chloride in aerosol
and canister adhesives, EPA anticipates workers spray apply the adhesive to substrates. The adhesives
are likely sold and used in sealed containers such as spray cans or canister tanks.
B.l.3.3 Paints and Coatings
Based on the Preliminary Information on Manufacturing, Processing, Distribution, Use, and Disposal:
Methylene Chloride and Use and Market Profile for Methylene Chloride, both available in the public
docket (EPA-HQ-OIF !), methylene chloride may be used in various paints and coatings for
industrial, commercial and consumer applications. Typical process descriptions and worker activities
for industrial and commercial uses in coating applications include manual application with roller or
brush, air spray systems, airless and air-assisted airless spray systems, electrostatic spray systems,
electrodeposition/electrocoating and autodeposition, dip coating, curtain coating systems, roll coating
systems and supercritical carbon dioxide systems (OECD, 2009b). After application, solvent-based
coatings typically undergo a drying stage in which the solvent evaporates from the coating (OECD,
2009b).
Methylene chloride is used for paint removal in a variety of industries, such as the automotive, aircraft,
construction and refinishing industries. Application methods include manual or automated application,
with techniques such as spray application, pouring, wiping and rolling. Additional details on this use of
methylene chloride can be found in the U.S. EPA (2014a) TSCA Work Plan Chemical Risk Assessment for
the use of methylene chloride as a paint remover. While paint and coating removal falls under the
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conditions of use for methylene chloride, scenarios already assessed in the 2014 risk assessment will
not be re-evaluated in the risk evaluation to which this scope applies. Therefore, this use is out of
scope for the risk evaluation.
B.1.3.4 Laundry and Dishwashing Products
Spot Cleaner
Methylene chloride is found in products used to spot clean garments (EPA-HQ-QPPT-2016-0742-0003).
Spot cleaning products can be applied to the garment either before or after the garment is dry cleaned.
The process and worker activities associated with commercial dry cleaning and spot cleaning have
been previously described in EPA's 1-Bromopropane Draft Risk Assessment (U.S. EPA. 2016d).
B.l.3.5 Lubricants and Greases
EPA identified several commercial and consumer lubricant products that contain methylene chloride.
These lubricants are used to reduce friction and wear and prevent seizing where metal-to-metal
contact is possible and inhibit rusting and corrosion by displacing water in a wide variety of
applications, including machinery, hardware, cables, and chains. The majority of these lubricant
products are aerosol lubricants (available in aerosol cans), although one liquid-based lubricant product
(available in pails and drums) was also identified. Aerosol lubricants are sprayed directly onto metal
substrates, while liquid lubricants may be brushed or spray applied to metal substrates. The methylene
chloride is anticipated to completely evaporate during the drying phase, leaving behind a lubricating
f i I m (Use and Market Profile for Methylene Chloride EPA-HQ-OPPT-2C )
B.l.3.6 Other Uses
Based on products identified in EPA's Preliminary Information on Manufacturing, Processing,
Distribution, Use, and Disposal: Methylene Chloride, EPA~HQ~QPPT~2016~0742~0003. a variety of other
uses may exist for methylene chloride, including use in weld spatter protectants, shoe polish, crafting
glues and cements, novelty items, and miscellaneous cleaners. It is unclear at this time the total
volume of methylene chloride used in any of these applications.
B.1.4 Disposal
Methylene chloride is a U-listed hazardous waste under code U080 under RCRA; therefore, discarded,
unused pure and commercial grades of methylene chloride are regulated as a hazardous waste under
RCRA (40 CFR § 261.33(f)). Additionally, methylene chloride is included in multiple waste codes under
the F-list of non-specific source wastes (40 CFR § 261.31(a)).
B.2 Occupational Exposure Data
EPA presents below an example of occupational exposure-related information from the preliminary
data gathering. EPA will consider this information and data in combination with other data and
methods for use in the risk evaluation.
Table_Apx B-l summarizes the industry sectors with methylene chloride OSHA CEHD data (OSHA.
2017).
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Table_Apx B-l. Summary of Industry Sectors with Methylene Chloride Personal Monitoring Air
Samples Obtained from OSHA Inspections Conducted Between 2011 and 2016
NAICS
Code
NAICS Description
238320
Painting and wall covering contractors
238390
Other building finishing contractors
313312
Textile and fabric finishing (except broadwoven fabric) mills a
315240
Women's, girls', and infants' cut and sew apparel manufacturing
316998
All other leather good and allied product manufacturing
321211
Hardwood veneer and plywood manufacturing
321911
Wood window and door manufacturing
321999
All other miscellaneous wood product manufacturing
322121
Paper (except newsprint) mills
323113
Commercial screen printing
325199
All other basic organic chemical manufacturing
325211
Plastics material and resin manufacturing
325212
Synthetic rubber manufacturing
325412
Pharmaceutical preparation manufacturing
325991
Custom compounding of purchased resins
325998
All other miscellaneous chemical product and preparation manufacturing
326150
Urethane and other foam product (except polystyrene) manufacturing
326199
All other plastics product manufacturing
327390
Other concrete product manufacturing
327991
Cut stone and stone product manufacturing
331316
Aluminum extruded product manufacturing b
331513
Steel foundries (except investment)
332312
Fabricated structural metal manufacturing
332321
Metal window and door manufacturing
332710
Machine shops
332811
Metal heat treating
332999
All other miscellaneous fabricated metal product manufacturing
333132
Oil and gas field machinery and equipment manufacturing
333921
Elevator and moving stairway manufacturing
334416
Capacitor, resistor, coil, transformer, and other inductor manufacturing
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NAICS
Code
NAICS Description
335121
Residential electric lighting fixture manufacturing
336211
Motor vehicle body manufacturing
337110
Wood kitchen cabinet and countertop manufacturing
337212
Custom architectural woodwork and millwork manufacturing
339950
Sign manufacturing
339999
All other miscellaneous manufacturing
423810
Construction and mining (except oil well) machinery and equipment merchant wholesalers
423930
Recyclable material merchant wholesalers
424610
Plastics materials and basic forms and shapes merchant wholesalers
424990
Other miscellaneous non-durable goods merchant wholesalers
443112
Radio, television, and other electronics stores c
443141
Household appliance stores
448190
Other clothing stores
451110
Sporting goods stores
485410
School and employee bus transportation
532299
All other consumer goods rental
541380
Testing laboratories
621511
Medical laboratories
713110
Amusement and theme parks
811111
General automotive repair
811121
Automotive body, paint, and interior repair and maintenance
811310
Commercial and industrial machinery and equipment (except automotive and electronic)
repair and maintenance
811420
Reupholstery and furniture repair
811490
Other personal and household goods repair and maintenance
926150
Regulation, licensing, and inspection of miscellaneous commercial sectors
a This is a 2007 NAICS code; the corresponding 2012 and 2017 NAICS code is 313310 for "Textile and Fabric Finishing Mills."
b This is a 2007 NAICS code; the corresponding 2012 and 2017 NAICS code is 331318 for "Other Aluminum Rolling,
Drawing, and Extruding."
c This is a 2007 NAICS code; the corresponding 2012 and 2017 NAICS code is 443142 for "Electronics Stores."
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