EPA Document# EPA-740-R1-7010
June 2017
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!¦! M lk. Environmental Protection Agency Pollution Prevention
EPA United States Office of Chemical Safety and
Scope of the Risk Evaluation for
Carbon Tetrachloride
(Methane, Tetrachloro-)
CASRN: 56-23-5
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TABLE OF CONTENTS
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 26
2.3.1 Fate and Transport 26
2.3.2 Releases to the Environment 28
2.3.3 Presence in the Environment and Biota 29
2.3.4 Environmental Exposures 30
2.3.5 Human Exposures 30
2.3.5.1 Occupational Exposures 30
2.3.5.2 Consumer Exposures 31
2.3.5.3 General Population Exposures 31
2.3.5.4 Potentially Exposed or Susceptible Subpopulations 32
2.4 Hazards (Effects) 33
2.4.1 Environmental Hazards 33
2.4.2 Human Health Hazards 34
2.4.2.1 Non-Cancer Hazards 34
2.4.2.2 Genotoxicity and Cancer Hazards 35
2.4.2.3 Potentially Exposed or Susceptible Subpopulations 35
2.5 Initial Conceptual Models 35
2.5.1 Initial Conceptual Model for Industrial and Commercial Activities and Uses: Potential
Exposures and Hazards 36
2.5.2 Initial Conceptual Model for Consumer Activities and Uses: Potential Exposures and
Hazards 38
2.5.3 Initial Conceptual Model for Environmental Releases and Wastes: Potential Exposures and
Hazards 40
2.6 Initial Analysis Plan 42
2.6.1 Exposure 42
2.6.1.1 Environmental Releases 42
2.6.1.2 Environmental Fate 42
2.6.1.3 Environmental Exposures 43
2.6.1.4 Occupational Exposures 43
2.6.1.5 Consumer Exposures 43
2.6.1.6 General Population 44
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2.6.2 Hazards (Effects) 44
2.6.2.1 Environmental Hazards 44
2.6.2.2 Human Health Hazards 45
2.6.3 Risk Characterization 45
REFERENCES 46
APPENDICES 49
Appendix A REGULATORY HISTORY 49
A.l Federal Laws and Regulations[[[ 49
A.2 State Laws and Regulations.............................................. 56
A3 International Laws and Regulations............. 56
Appendix B PROCESS, RELEASE AND OCCUPATIONAL EXPOSURE INFORMATION 58
B.l Process Information 58
B.l.l Manufacture (Including Import) 58
B.l.1.1 Domestic Manufacture 58
B.l.1.2 Import 59
B.l.2 Processing and Distribution 59
B.l.2.1 Reactant or Intermediate 59
B.l.2.2 Incorporation into a Formulation, Mixture or Reaction Products 60
B.l.2.3 Incorporation into an Article 60
B.l.2.4 Repackaging 60
B.l.2.5 Recycling 61
B.l.3 Uses 63
B.l.3.1 Petrochemical Manufacturing 63
B.l.3.2 Agricultural Products Manufacturing 63
B.l.3.3 Solvents for Cleaning and Degreasing 63
B.l.3.4 Adhesive and Sealants 64
B.l.3.5 Paints and Coatings 64
B.l.3.6 Laboratory Chemicals 64
B.l.3.7 Other Uses 65
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LIST OF TABLES
Table 1-1. Assessment History of Carbon Tetrachloride 15
Table 2-1. Physical and Chemical Properties of Carbon Tetrachloride 18
Table 2-2. Production Volume of Carbon Tetrachloride in Chemical Data Reporting (CDR) Reporting
Period (2012 to 2015) 20
Table 2-3. Categories and Subcategories of Conditions of Use for Carbon Tetrachloride 23
Table 2-4. Environmental Fate Characteristics of Carbon Tetrachloride 27
Table 2-5. Summary of Carbon Tetrachloride TRI Production-Related Waste Managed in 2015 (lbs).... 28
Table 2-6. Summary of Carbon Tetrachloride TRI Releases to the Environment in 2015 (lbs) 28
LIST OF FIGURES
Figure 2-1. Initial Carbon Tetrachloride Life Cycle Diagram 21
Figure 2-2. Initial Carbon Tetrachloride Conceptual Model for Industrial and Commercial Activities and
Uses: Potential Exposures and Hazards 37
Figure 2-3. Initial Carbon Tetrachloride Conceptual Model for Consumer Activities and Uses: Potential
Exposures and Hazards 39
Figure 2-4. Initial Carbon Tetrachloride Conceptual Model for Environmental Releases and Wastes:
Potential Exposures and Hazards 41
LIST OF APPENDIX TABLES
Table_Apx A-l. Federal Laws and Regulations 49
Table_Apx A-2. State Laws and Regulations 56
Table_Apx A-3. Regulatory Actions by other Governments and Tribes 56
Table_Apx B-l. Summary of Industry Sectors with Carbon Tetrachloride Personal Monitoring Air
Samples Obtained from OSHA Inspections Conducted Between 2013 and 2016 65
LIST OF APPENDIX FIGURES
Figure_Apx B-l. General Process Flow Diagram for Solvent Recovery Processes 62
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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, Office of Air and Radiation, 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 IP A- IH Q-0 IP IPT-20 3» »¦ 3.
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 U.S. Government.
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ABBREVIATIONS
°c
Degrees Celsius
AAL
Allowable Ambient Levels
atm
Atmosphere(s)
ATSDR
Agency for Toxic Substances and Disease Registries
AWQC
Ambient Water Quality Criteria
BCF
Bioconcentration Factor
BUN
Blood Urea Nitrogen
CAA
Clean Air Act
CASRN
Chemical Abstract Service Registry Number
CBI
Confidential Business Information
CDR
Chemical Data Reporting
CEHD
Chemical Exposure Health Data
CERCLA
Comprehensive Environmental Response, Compensation and Liability Act
CFC
Chlorofluorocarbon
cm3
Cubic Centimeter(s)
CNS
Central Nervous System
COC
Concentration of Concern
CoRAP
Community Rolling Action Plan
CPCat
Chemical and Product Categories
CPSC
Consumer Product Safety Commission
CS2
Carbon Disulfide
CSATAM
Community-Scale Air Toxics Ambient Monitoring
CSCL
Chemical Substances Control Law
CYP450
Cytochrome P450
CWA
Clean Water Act
DNA
Deoxyribonucleic Acid
DT50
Dissipation Time for 50% of the compound to dissipate
EC
European Commission
ECHA
European Chemicals Agency
EDC
Ethylene Dichloride
EG
Effluent Guidelines
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
FHSA
Federal Hazardous Substance Act
FIFRA
Federal Insecticide, Fungicide, and Rodenticide Act
g
Gram(s)
Gl
Gastrointestinal
HAP
Hazardous Air Pollutant
HCFC
Hydrochlorofluorocarbons
HCI
Hydrochloric Acid
HFC
Hydrofluorocarbon
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HFO Hydrofluoroolefin
HPV High Production Volume
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
km Kilometer(s)
L Liter(s)
lb Pound
log Koc Logarithmic Soil Organic Carbon:Water Partitioning Coefficient
log Kow Logarithmic OctanokWater 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
mPa-s Millipascal(s)-Second
MSDS Material Safety Data Sheet
NAICS North American Industrial Classification System
NATA National Air Toxics Assessment
NATTS National Air Toxics Trends Stations
NEI National Emissions Inventory
NESHAP National Emission Standards
NHANES National Health and Nutrition Examination Survey
NIH National Institute of Health
NIOSH National Institute of Occupational Safety and Health
NPDWR National Primary Drinking Water Regulations
NTP National Toxicology Program
NWQMC National Water Quality Monitoring Council
OCSPP Office of Chemical Safety and Pollution Prevention
ODS Ozone Depleting Substance
OECD Organisation for Economic Co-operation and Development
OELs Occupational Exposure Limits
OPPT Office of Pollution Prevention and Toxics
OSHA Occupational Safety and Health Administration
OW Office of Water
PCE Perchloroethylene
PEL Permissible Exposure Level
POD Point of Departure
POTW Publicly Owned Treatment Works
ppm Part(s) per Million
QC Quality Control
REACH Registration, Evaluation, Authorisation and Restriction of Chemicals
RCRA Resource Conservation and Recovery Act
REI Reactive Ion Etching
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SDS
Safety Data Sheet
SDWA
Safe Drinking Water Act
SIAP
Screening Information Dataset Initial Assessment Profile
SIDS
Screening Information Dataset
SDWA
Safe Drinking Water Act
STEL
Short-term Exposure Limit
STORET
STORage and RETrieval
TCCR
Transparent, Clear, Consistent and Reasonable
TCLP
Toxicity Characteristic Leaching Procedure
TRI
Toxics Release Inventory
TSCA
Toxic Substances Control Act
TURA
Toxic Use Reduction Act
TWA
Time-Weighted Average
UATMP
Urban Air Toxics Monitoring Program
U.S.
United States
USGS
United States Geological Survey
UV
Ultraviolet
VOC
Volatile Organic Compounds
WHO
World Health Organisation
WQP
Water Quality Portal
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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). Carbon tetrachloride 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
carbon tetrachloride.
This document presents the scope of the risk evaluation to be conducted for carbon tetrachloride. 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.
In the case of carbon tetrachloride, legacy uses and associated legacy disposals will be excluded from
the scope of the risk evaluation. EPA is excluding these uses because EPA interprets the mandates
under section 6(a)-(b) to conduct risk evaluations and any corresponding risk management to focus on
current and prospective uses, 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.
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 carbon tetrachloride. This problem
formulation is expected to be released within approximately 6 months of publication of the scope.
Carbon tetrachloride is a high production volume solvent. The Montreal Protocol and Title VI of the
Clean Air Act (CAA) Amendments of 1990 called for a complete phase-out of carbon tetrachloride
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production for non-feedstock uses by 2000 and the Consumer Product Safety Commission (CPSC)
banned the use of carbon tetrachloride in consumer products (excluding unavoidable residues not
exceeding 10 ppm atmospheric concentration) in 1970. Currently, carbon tetrachloride is used a
feedstock in the production of hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs) and
hydrofluoroolefins (HFOs) and in the manufacturing of other chlorinated compounds, agricultural
products and petrochemicals. EPA has identified information on several other uses that may still exist
including solvents for laboratory uses, degreasing and cleaning, adhesives, sealants, paints, coatings,
rubber, cement and asphalt formulations.
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. It is expected that inhalation will be the primary route
of exposure to all populations.
This document presents the occupational scenarios in which workers and occupational non-users may
be exposed carbon tetrachloride during a variety of conditions of use, such as manufacturing of
refrigerants or chlorinated compounds and using solvents for machinery cleaning. For carbon
tetrachloride, 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. Most of the reported
environmental releases for carbon tetrachloride were air emissions (fugitive and point source air
emissions). Other reported releases include land disposal, ground injection and water releases. EPA
expects to consider these releases as they relate to exposures to occupational, consumer and general
populations.
Carbon tetrachloride has been the subject of numerous health hazard reviews including EPA's
Integrated Risk Information System (IRIS) Toxicological Review and Agency for Toxic Substances and
Disease Registry's (ATSDR's) Toxicological Profile. Any existing assessments will be a starting point as
EPA will conduct a systematic review of the literature, including new literature since the existing
assessments, as available in Carbon tetrachloride (CASRN 56-23-5) Bibliography: Supplemental File for
the TSCA Scope Document, IE IP A- IH Q-Q IP PT-2016-0733. Human health hazards of carbon tetrachloride
have been identified by EPA previously and include liver toxicity, renal toxicity and cancer. Carbon
tetrachloride hazards to fish, aquatic invertebrates, aquatic plants, sediment invertebrates and
amphibians have previously been assessed by EPA or other organizations. 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
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for carbon tetrachloride. The initial analysis plan will be used to develop the problem formulation and
final analysis plan for the risk evaluation of carbon tetrachloride.
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1 INTRODUCTION
This document presents the scope of the risk evaluation to be conducted for carbon tetrachloride. If a
condition of use has not been discussed, 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 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). 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 10 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 10
chemical substances. EPA used this information in developing this scope document, which fulfills the
TSCA § 6(b)(4)(D) requirement for carbon tetrachloride.
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
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unsubstantiated or anecdotal statement (or even a few isolated statements) on the internet that a
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 of 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
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accordance with amendments to TSCA. EPA expects to collect and screen much of the relevant
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 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. 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 carbon tetrachloride. 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
Carbon tetrachloride 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.
State Laws and Regulations
Carbon tetrachloride 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.
Laws and Regulations in Other Countries and International Treaties or Agreements
Carbon tetrachloride 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.
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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
Carbon tetrachloride (CASRN 56-23-5) Bibliography: Supplemental File for the TSCA Scope Document,
E IP A- HI 0,-0 IP PT- 2016-0 ? 3 3) using the literature search strategy (see Strategy for Conducting Literature
Searches for Carbon Tetrachloride: Supplemental File for the TSCA Scope Document, EPA-HQ-OPPT-
2| 33) to ensure that EPA is considering information that has been made available since these
assessments were conducted.
Table 1-1. Assessment History of Carbon Tetrachloride
Authoring Organization
Assessment
EPA assessments
U.S. EPA, Office of Water (OW)
Update of Human Health Ambient Water Quality
Criteria: Carbon Tetrachloride 56-23-5. EPA-HQ-
OW-2014-0135-0182 (2015b)
U.S. EPA, Integrated Risk Information System (IRIS)
Toxicological Review o m Tetrachloride In
Support of Summary Information on IRIS (2010)
U.S. EPA, Office of Drinking Water
Carb achloride Health Advisory, Office of
Drinking Water US Environmental Protection
Agency(1987)
Other U.S.-based organizations
Agency for Toxic Substances and Disease Registry
(ATSDR)
Toxicological Profile for Carbon Tetrachloride
(2005)
California Environment Protection Agency, Office
of Environmental Health Hazard Assessment
Public Health Goal for Carbon Tetrachloride
(2000)
International
Health Canada
elines for Canadian Drinking Water Quality,
Guideline Technical Document < e
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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 identified by virtue of
greater exposure; ecological hazard; and human health hazard, including potentially exposed or
susceptible subpopulations identified by virtue of greater susceptibility.
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
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. The Strategy for Conducting Literature Searches for
Carbon Tetrachloride: Supplemental File for the TSCA Scope Document, EPA-HQ-O IP PT-2016-0733
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 the Strategy for Conducting Literature Searches for Carbon Tetrachloride: Supplemental File for the
TSCA Scope Document, EPA-Hl- OUT I u 11 ¦> ¦ 3. 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; 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 Strategy for Conducting Literature Searches for Carbon
Tetrachloride: Supplemental File for the TSCA Scope Document, EPA-HQ-QPPT-2016-0733 discusses the
inclusion and exclusion criteria that EPA/OPPT used to categorize references as on-topic or off-topic.
Page 16 of 65
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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 the Strategy for Conducting Literature
Searches for Carbon Tetrachloride: Supplemental File for the TSCA Scope Document, IEIPA~HQ~GPPT~
2j 33 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 can be found in the Carbon tetrachloride (CASRN 56-23-
5) Bibliography: Supplemental File for the TSCA Scope Document, IE PA-H Q-0 IP PT-2Q16-0733. 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.
Page 17 of 65
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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 carbon tetrachloride 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 of carbon tetrachloride.
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 Carbon Tetrachloride
Property
Valuea
References
Molecular formula
ecu
Molecular weight
153.82
Physical form
Colorless liquid, sweet, aromatic and ethereal
odor resembling chloroform
Merck (1996); U.S. Coast
Guard (1985)
Melting point
-23°C
L 99]
Boiling point
76.8°C
Lide (1999)
Density
1.46 g/cm3 at 20°C
Boublik et al. {1934)
Vapor pressure
115 mm Hg at 25°C
Lide (1999)
Vapor density
5.32 (relative to air)
Boublik et al. (1984)
Water solubility
793 mg/L at 25°C
Horvath (1982)
Octanol:water partition
coefficient (log Kow)
2.83
Hansch et al. (1995)
Henry's Law constant
0.0276 atm m3/mole
Leighton and C; 51)
Flash point
None
U.S. Coast Guard (1985)
Autoflammability
Not readily available
Viscosity
2.03 mPa-s at -23°C
Daubert and Danner
11-^91
Refractive index
1.4607 at 20°C
Merck (1996)
Page 18 of 65
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Property
Valuea
References
Diaelectric constant
2.24 at 20°C
Norbert and Dean (196
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 Carbon
Tetrachloride, E IP A- IHIQ-OP PT-2016-0733). 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: Carbon Tetrachloride, EPA-HQ-QPPT-2016-
0733-0003) 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. As further
described in this document, EPA searched a number of available data sources (e.g., Use and Market
Profile for Carbon Tetrachloride, E PA-IH Q-0 P PT-2016-0733).
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 in commerce
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
industrial, 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 of use may be grouped under multiple CDR categories.
For the purposes of this scope, CDR definitions were used. CDR 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. 2016b).
Page 19 of 65
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To understand conditions of use relative to one another and associated potential exposures under
those conditions of use, the life cycle diagram includes the production volume associated with each
stage of the life cycle, as reported in the 2016 CDR (U.S. EPA. 2017b, 2016b), when the volume was not
claimed confidential business information (CBI). The 2016 CDR reporting data for carbon tetrachloride
are provided in Table 2-2 for carbon tetrachloride from EPA's CDR database (U.S. EPA. 2017b).
Table 2-2. Production Volume of Carbon Tetrachloride in Chemical Data Reporting (CDR) Reporting
Period (2012 to 2015)a
Reporting Year
2012
2013
2014
2015
Total Aggregate
Production Volume (lbs)
129,145,698
116,658,281
138,951,153
142,582,067
a U.S. EPA (2017b). Internal communication. The CDR data for the 2016 reporting period is available via ChemView
(https://iava.epa.gov/chemview) (U.S. EPA, 2016b). Because of an ongoing CBI substantiation process required bv
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 carbon tetrachloride from manufacture to the point
of disposal. This diagram does not distinguish among most industrial, commercial and consumer uses;
EPA will further investigate and define the differences between these uses during the risk evaluation. It
should be noted that the Montreal Protocol and Title VI of the Clean Air Act (CAA) Amendments of
1990 called for a complete phase-out of carbon tetrachloride production for non-feedstock uses by
2000 and the Consumer Product Safety Commission (CPSC) banned the use of carbon tetrachloride in
consumer products (excluding unavoidable residues not exceeding 10 ppm atmospheric concentration)
in 1970. During preliminary data gathering, EPA has identified use as a feedstock as the main use for
carbon tetrachloride. However, there are several industrial/commercial/consumer uses that may still
exist including: catalyst regeneration, as a processing aid and as an additive in petrochemical
manufacturing; in the manufacturing of agricultural products; as a solvent for degreasing and cleaning,
in adhesives, sealants, paints, coatings, rubber cement and asphalt formulations and for laboratory
procedures (i.e., extraction solvent) rEPA-HQ-QPPT-2016-0733-0003 (U.S. EPA. 2017c)l. EPA expects
that some commercial products containing carbon tetrachloride are also available for purchase by
consumers, such that many products are used in both commercial and consumer applications. Most of
the products EPA identified that contain carbon tetrachloride as a cleaning solvent or as a solvent in
formulation have less than 1% by weight carbon tetrachloride. For instance, there are public
comments, EPA~HQ~OPPT~2016~0733~0005 and EPA-HQ-QPPT-2016-0733-0017. stating that carbon
tetrachloride may be present in a limited number of industrial products with chlorinated ingredients at
a concentration of less than 0.003% by weight. EPA will further investigate carbon tetrachloride use in
these products during the risk evaluation process.
Due to CBI claims in the 2016 CDR, EPA cannot provide the volumes associated with each life cycle
stage (U.S. EPA. 2016b).
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MFG/IMPORT
PROCESSING
INDUSTRIAL, COMMERCIAL, CONSUMER USES b
Manufacture
(includes import)
(142.6 Million lbs)
Processing as
Reactant/lntermediate
(Volume CBI)
e.gJntormediate for
refrigerant manufacture?;
other chlorinated
Incorporated into
Formulation, Mixture,
or Reaction Products
(Volume not reported)
Incorporated i
'olume not reported)
Repackaging
(Volume not reported)
Recycling
Petrochemical and
Agricultural Products
Manufacturing
(Volume CBI or not reported)
e.g. catalyst regeneration,
processing aid, additive?
Solvents for Cleaning and
Decreasing
(Volume not reported)
e.g., machinery cleaning, textile
cleaning, brake? cleaning
Adhesives and Sealants
(Volume not reported)
e.g., solvent for rubber cement and
asphalt
Paints and Coatings
(Volume not reported)
e.g., swimming pool paints, traffic
paints, other coatings
Laboratory Chemicals
e.g., extraction solvent
Other Uses
.'.9., reactive? ion e?tching, processing
aid, me?tal re?cove;ry
RELEASES and WASTE DISPOSAL
h
Emissions to Air
Wastewaterc
Liquid Wastes c
Solid Wastes
See Figure 2-4 for Environmental Releases
and Wastes
Manufacture (includes Import)
Processing
Industrial/commercial use
Uses. At the scope level of detail in the
life cycle diagram, EPA is not
distinguishingbetween most
industrial/com mercial/consumer uses
for carbon tetrachloride.The differences
betweenthesewill be further
investigated and defined later in the risk
evaluation process.
Figure 2-1. Initial Carbon Tetrachloride 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. 2016b). Activities related to distribution (e.g., loading, unloading) will
be considered throughout the carbon tetrachloride life cycle, rather than using a single distribution scenario.
a Due to CBI claims, EPA cannot differentiate between manufacturing and import sites.
bSee Table 2-3 for additional uses not mentioned specifically in this diagram.
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 65
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Descriptions of the industrial, commercial and consumer use categories identified from the 2016 CDR
(U.S. EPA. 2016b) and included in the life cycle diagram are summarized below. The descriptions
provide a brief overview of the use category; Appendix B contains more detailed descriptions (e.g.,
process descriptions, worker activities, process flow diagrams, equipment illustrations) for each
manufacture, 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 2016
L emicaI Data Reporting (U.S. EPA. 2016a).
For the uses, the "Petrochemical and Agricultural Products Manufacturing" category encompasses
chemical substances used for a variety of purposes at petrochemical and agricultural products
manufacturing sites. This category includes the use of carbon tetrachloride for catalyst regeneration, as
a processing aid and as an additive.
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 carbon tetrachloride in vapor degreasing, cold
cleaning and in industrial and commercial aerosol degreasing products.
The "Adhesives and Sealants" category encompasses chemical substances contained in adhesive and
sealant products used to fasten other materials together. EPA anticipates that the primary subcategory
to be the use of carbon tetrachloride in rubber cement, asphalt and other solvent-based adhesives and
sealants. This category covers industrial, commercial and consumer uses of adhesives and sealants.
The "Paints and Coatings" category encompasses chemical substances contained in paints, lacquers,
varnishes and other coating products that are applied as a thin continuous layer to a surface. Coating
may provide protection to surfaces from a variety of effects such as corrosion and ultraviolet (UV)
degradation; may be purely decorative; or provide other functions. EPA anticipates that the primary
subcategory to be the use of carbon tetrachloride in solvent-based paints or other coatings. This
category covers industrial, commercial and consumer uses of paints and coatings.
Table 2-3 summarizes each life cycle stage and the corresponding categories and subcategories of
conditions of use for carbon tetrachloride 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.
Page 22 of 65
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Table 2-3. Categories and Subcategories of Conditions of Use for Carbon Tetrachloride
Life Cycle Stage
Categorya
Subcategory b
References
Manufacture
Domestic
manufacture
Domestic manufacture
Import
Import
U.S. EPA (2016b)
Processing
Processing as a
reactant/
intermediate
Hyd rochlorofluorocarbons
(HCFCs), Hydrofluorocarbon
(HFCs) and Hydrofluoroolefin
(HFOs)
Use document, EPA-HQ-
OPPT-2016-07BB-0003:
Public comments, EPA-
HQ-OPPT-2016-0733-
0 . 1Q-OPPT-
2016-0733-0008 and
EPA-HQ-OPPT-2016-
0733-0016: U.S. EPA
(2016b)
Perchloroethylene (PCE)
Use document, EPA-HQ-
OPPT-2016-0733-0003:
Public comments, EPA-
HQ-OPPT-2016-0733-
0007 and EPA-HQ-OPPT-
2016-0733-0008: U.S.
EPA(2016b)
Inorganic chlorinated
compounds
Public comment, EPA-
HQ-OPPT-2016-0733-
0027
Chlorinated paraffins
Public comment, EPA-
HQ-OPPT-2016-0733-
0024
Processing -
incorporation into
formulation, mixture
or reaction product
Petrochemicals
manufacturing
U.S. )16b): Use
document, EPA-HQ-
OPPT-2016-0733-0003:
U.S. EPA (2016a)
Processing
Processing -
incorporation into
formulation, mixture
or reaction product
Agricultural products
manufacturing
U.S. EPA (2016b): Use
document, EPA-HQ-
OPPT-2016-0733-0003:
Public comments, EPA-
HQ-OPPT-2016-0733-
0007 and EPA-HQ-OPPT-
2016-0733-0008
Page 23 of 65
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Life Cycle Stage
Categorya
Subcategory b
References
Solvents for cleaning and
degreasing
Use document, EPA-H(
OPPT-2016-0733-0003:
Public comment, EPA-
HQ-OPPT-2016-0733-
0011, EPA-HQ-OPPT-
2016-0733-0012 and
EPA-HQ.-OPPT-2016-
0733-0015
Adhesives and sealants
Use document, EPA-HQ-
OPPT-2016-0733-0003:
Public comment, EPA-
HQ-OPPT-2016-0733-
0011.
Paints and coatings
Use document, EPA-HQ-
OPPT-2016-0733-0003
Processing -
incorporation into
article
Incorporation into article
U.S. EPA (2016a)
Processing -
repackaging
Repackaging
U.S. EPA (2016a)
Recycling
Recycling
U.S. EPA (2016b), U.S.
EPA (2016a)
Distribution in
commerce
Distribution
Distribution in commerce
Use document, EPA-HQ-
OPPT-2016-0733-0003
Industrial Use
Petrochemical
manufacturing
Catalyst regeneration
Use document, EPA-HQ-
OPPT-2016-0733-0003
Industrial Use
Petrochemical
manufacturing
Processing aid
Use document, EPA-HQ-
OPPT-2016-0733-0003:
U.S. EPA (2016b)
Additive
Use document, EPA-HQ-
OPPT-2016-0733-0003:
Public comment, EPA-
HQ-OPPT-2016-0733-
0012: U.S. EPA (2016a)
Agricultural
products
manufacturing
Fertilizers and other
agricultural products
manufacturing
U.S. EPA (2016b), Use
document, EPA-HQ-
OPPT-2016-0733-0003:
Public comments, EPA-
HQ-OPPT-2016-0733-
Page 24 of 65
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Life Cycle Stage
Categorya
Subcategory b
References
0007 and EPA-HQ-QPP
2016-0733-0008
Industrial/commercial/
consumer use
Solvents for cleaning
and degreasing
Machinery cleaning
Use document, EPA-HQ-
OPPT-2016-0733-0003:
Public comment, EPA-
HQ-OPPT-2016-0733-
0011
Textile cleaning
Use document, EPA-HQ-
QPPT-2016-0733-0003
Brake cleaning
Use document, EPA-HQ-
OPPT-2016-0733-0003
Adhesives and
sealants
Rubber cement
Use document, EPA-HQ-
OPPT-2016-0733-0003
Arts and crafts
Use document, EPA-HQ-
OPPT-2016-0733-0003:
Public comment, EPA-
HQ-OPPT-2016-0733-
0015
Asphalt
Use document, EPA-HQ-
OPPT-2016-0733-0003
Industrial/commercial/
consumer use
Adhesives and
sealants
Industrial adhesives
Use document, EPA-HQ-
OPPT-2016-0733-0003:
Public comments, EPA-
HQ-OPPT-2016-0733-
0011, EPA-HQ-OPPT-
2016-0733-0012, and
EPA-HQ-OPPT-2016-
0733-0015
Paints and coatings
Paints and coatings
Use document, EPA-HQ-
OPPT-2016-0733-0003
Page 25 of 65
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Life Cycle Stage
Categorya
Subcategory b
References
Laboratory
chemicals
Laboratory chemical
Use document, EPA-H(
OPPT-2016-0733-0003:
U.S. EPA {2016b). Public
comments, EPA-HQ-
OPPT-2016-0733-0007
and EPA-HQ-OPPT-
2016-0733-0013
Disposal
Other uses
Reactive ion etching
Use document, EPA-HQ-
OPPT-2016-0733-0003
Processing aid (e.g., metal
recovery, nitrogen
trichloride removal in chlor-
alkali production).
Use document, EPA-HQ-
OPPT-2016-0733-0003:
Public comments, EPA-
HQ-OPPT-2016-0733-
0007 and EPA-HQ-OPPT-
2016-0733-0027
Emissions to air
Emissions to air
U.S. EPA (2016a)
Wastewater
Wastewater
U.S. EPA (2016a)
Liquid wastes
Liquid wastes
U.S. EPA (2016a)
Solid wastes
Solid wastes
U.S. EPA (2016a)
aThese categories of conditions of use appear in the Life Cycle Diagram, reflect CDR codes and broadly represent
conditions of use of carbon tetrachloride in industrial and/or commercial settings.
bThese subcategories reflect more specific uses of carbon tetrachloride.
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 carbon tetrachloride. Post-release pathways and
routes will be described to characterize the relationship or connection between the conditions of use
of carbon tetrachloride 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
carbon tetrachloride.
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 carbon tetrachloride.
Page 26 of 65
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Table 2-4. Environmental Fate Characteristics of Carbon Tetrachloride
Property or Endpoint
Valuea
References
Direct photodegradation
Minutes (atmospheric -stratospheric)
OECD (2011)
Indirect photodegradation
>330 years (atmospheric)
OECD (2011)
Hydrolysis half-life
7000 years at 1 ppm
011)
Biodegradation
6 to 12 months (soil)
7 days to 12 months (aerobic water,
based on multiple studies)
3 days to 4 weeks (anaerobic water,
based on multiple studies)
011)
ECHA (2012)
ATS DR. (2005)
HSDB (2005)
Bioconcentration factor (BCF)
30 bluegill sunfish
40 rainbow trout
011)
Bioaccumulation factor (BAF)
19 (estimated)
U.S. EPA (2012b)
Soil organic carbon:water
partition coefficient (log Koc)
1.69-2.16
ECHA (2012)
2.06 (weighted mean of two soils-silt
loam and sandy loam)
OECD (2011)
a Measured unless otherwise noted.
Carbon tetrachloride shows minimal susceptibility towards indirect photolysis by hydroxyl radicals in
the troposphere, where it's estimated tropospheric half-life exceeds 330 years. Ultimately, carbon
tetrachloride diffuses upward into the stratosphere where it is photodegraded to form the
trichloromethyl radical and chlorine atoms (OECD, 2011). Further, carbon tetrachloride is efficiently
degraded by direct photolysis under stratospheric conditions and the DT50 (Dissipation Time for 50% of
the compound to dissipate) value is in the order of minutes. However, the troposphere to the
stratosphere migration of carbon tetrachloride is very long and this migration time limits the
dissipation. The rate of photodegradation increases at altitudes >20 km and beyond.
Carbon tetrachloride dissolved in water does not photodegrade or oxidize in any measurable amounts,
with a calculated hydrolysis half-life of 7,000 years based on experimental data at a concentration of
1 ppm (OECD, 2011). Removal mechanisms from water could include volatilization due to the Henry's
law constant and anaerobic degradation in the sediment.
Based on the available environmental fate data, carbon tetrachloride is likely to biodegrade slowly
under aerobic conditions with pathways that are environment- and microbial population-dependent.
Anaerobic degradation has been observed to be faster than aerobic degradation under some
conditions with acclimated microbial populations. Anaerobic biodegradation is expected to be a
significant degradation mechanism in soil and ground water. Estimated and measured BCF and BAF
values ranging from 19 - 40 indicates that carbon tetrachloride has no significant bioaccumulation
potential in plants and animals (U.S. EPA. 2012b; OECD, 2011).
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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, carbon tetrachloride 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
carbon tetrachloride reported by industrial facilities to the TRI program for 2015 (U.S. EPA. 201?d).
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 Carbon Tetrachloride TRI Production-Related Waste Managed in 2015 (lbs)
Number of
Energy
Total Production
Facilities
Recycling
Recovery
Treatment
Releasesa,b
Related Waste
47
5,954,066
5,638,154
15,196,739
151,690
26,940,648
Data source: 2015 TRI Data (updated March 2017) U.S. EPA (2017d).
a 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 Does not include releases due to one-time event not associated with production such as remedial actions or
earthquakes.
In 2015, 47 facilities reported a total of 27 million pounds of carbon tetrachloride waste managed. Of
this total, nearly 6 million pounds were recycled, 5.6 million pounds were recovered for energy,
15 million pounds were treated, and almost 152 thousand pounds were released into the environment.
Of these releases, the largest releases of nearly 105 thousand pounds were to air (fugitive and point
source air emissions), a little under 500 pounds were released to water (surface water discharges),
50 thousand pounds were released to land (of which disposal to Resource Conservation and Recovery
Act (RCRA) Subtitle C landfills is the primary disposal method), and under 200 pounds were released in
other forms such as indefinite storage.
Table 2-6. Summary of Carbon Tetrachloride TRI Releases to the Environment in 2015 (lbs)
Air Releases
Land Releases
Number
of
Facilities
Stack
Air
Releases
Fugitive
Air
Releases
Water
Releases
Class 1
Under-
ground
Injection
RCRA
Subtitle C
Landfills
All other
Land
DisposalJ
Other
Releases *
Total
Releasesb
Subtotal
69,897
34,941
19,608
27,300
401
Totals
47
104,838
468
47,309
164
152,780
Data source: 2015 TRI Data (updated March 2017) U.S. EPA (2017di
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.
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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. 2016a).
Other sources of information provide evidence of releases of carbon tetrachloride, including EPA
effluent guidelines (EGs) promulgated under the Clean Water Act (CWA), National Emission Standards
for Hazardous Air Pollutants (NESHAPs) promulgated under the CAA or other EPA standards and
regulations that set legal limits on the amount of carbon tetrachloride 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 carbon tetrachloride.
2.33 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 carbon tetrachloride.
Though carbon tetrachloride's use has significantly decreased from a peak in the 1970's, it's long half-
life and previous ubiquitous use and disposal has resulted in the continued presence in various
environmental media (ATSDR. 2005). Carbon tetrachloride is listed as a Hazardous Air Pollutant (HAP)
and is included in several multi-year monitoring programs, with data collected across the nation in
both urban and rural locations (U.S. EPA. 2017a. 1996). For example, carbon tetrachloride is included in
all three ambient air monitoring programs, collectively known as the National Monitoring Programs:
National Air Toxics Trends Stations (NATTS) network, Community-Scale Air Toxics Ambient Monitoring
(CSATAM) Program and Urban Air Toxics Monitoring Program (UATMP). NATTS sites are based on
preliminary air toxics programs such as the 1996 National Air Toxics Assessment (NATA).
According to the 2015 National Air Toxics Inventory, ambient air monitoring trends from 2003 to 2013
have shown that of the eight hazardous air pollutants monitored, only carbon tetrachloride average
concentrations have slightly increased in the atmosphere over the 10-year period. This is likely
primarily due to its extremely long half-life in the troposphere (U.S. EPA. 2015a).
Carbon tetrachloride is specifically regulated under the Safe Drinking Water Act (SDWA). Therefore,
under the National Primary Drinking Water Regulations, Carbon tetrachloride is designated as a volatile
organic compound (VOC) contaminant and is monitored in drinking water (U.S. EPA. 2009).
The U.S. Geological Survey (USGS) monitors organic compounds in ground water and has detected
carbon tetrachloride in community water systems (USGS, 2007). The U.S. EPA provides the public with
storage and retrieval (STORET) data that maps monitoring sites and allows for download of sampling
data of surface water monitoring sites. These data are searchable via the Water Quality Portal (WQP),
a cooperative service sponsored by the USGS, the EPA and the National Water Quality Monitoring
Council (NWQMC) (NWQMC, 2017). The portal contains data collected by over 400 state, federal, tribal
and local agencies.
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Biomonitoring data on carbon tetrachloride are collected in the National Health and Nutrition
Examination Survey (NHANES) (CDC. 2017).
2.3.4 Environmental Exposures
The manufacturing, processing, distribution in commerce use and disposal of carbon tetrachloride 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 carbon tetrachloride.
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
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.
Workers and occupational non-users may be exposed to carbon tetrachloride when performing
activities associated with the conditions of use described in Section 2.2, including, but not limited to:
• Unloading and transferring carbon tetrachloride to and from storage containers to process
vessels.
• Using carbon tetrachloride in process equipment.
• Applying formulations and products containing carbon tetrachloride onto substrates (e.g., spray
applying coatings or adhesives containing carbon tetrachloride).
• Cleaning and maintaining equipment.
• Sampling chemical, formulations or products containing carbon tetrachloride for quality control
(QC).
• Repackaging chemical, formulations or products containing carbon tetrachloride.
• Handling, transporting and disposing waste containing carbon tetrachloride.
• Use of carbon tetrachloride in laboratories.
• Performing other work activities in or near areas where carbon tetrachloride is used.
Based on these activities, EPA expects to consider inhalation exposure to vapor and mists and dermal
exposure, including skin contact with liquids and vapors for workers and occupational non-users. 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 carbon tetrachloride:
including an OSHA Permissible Exposure Limit (PEL) of 10 ppm time-weighted average (TWA) and
25 ppm ceiling and a National Institute for Occupational Safety and Health (NIOSH) Recommended
Exposure Limit (REL) of 2 ppm (12.6 mg/m3) 60-minute Short-term Exposure Limit (STEL). Also, NIOSH
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indicates that carbon tetrachloride has an immediately dangerous to life and health (IDLH) value of
200 ppm based on acute inhalation toxicity data in humans, and provides a notation that carbon
tetrachloride is considered a potential occupational carcinogen. The influence of these exposure limits
on occupation exposures will be considered in the occupational exposure assessment.
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
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 carbon tetrachloride personal monitoring air samples obtained from OSHA
inspections conducted between 2013 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
Carbon tetrachloride can be found in consumer products and/or commercial products that are readily
available for public purchase at common retailers [ sections 3 and 4,
(U.S. EPA. 201?c)1. which can therefore result in exposures to consumers.
Exposures routes for consumers using carbon tetrachloride-containing products may include inhalation
of vapors and aerosols (spray applications), dermal exposure to products. Although unlikely given the
physical-chemical properties, EPA also expects to consider incidental ingestion due to eating and/or
drinking during and immediately after product use.
EPA expects to consider inhalation, dermal and oral exposures to consumers and bystanders associated
with consumer use.
2.3.5.3 General Population Exposures
Wastewater/liquid wastes, solid wastes or air emissions of carbon tetrachloride 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
The volatility of carbon tetrachloride makes inhalation exposures a likely exposure pathway when it is
released (via air or as a result of waste disposal) during industrial, commercial or consumer uses (see
Figure 2-4). Inhalation of carbon tetrachloride, due to its volatilization, during household use of
contaminated water (e.g., during bathing/showering, dishwashing) could be a source of exposure to
the general population.
Vapor intrusion is an additional source of exposure in indoor environments. VOCs such as carbon
tetrachloride can migrate upwards toward the ground surface and into overlying buildings through
gaps and cracks in foundation slabs or basement walls. This route from a subsurface source to the air
inside a building is referred to as the vapor intrusion pathway (U.S. EPA, 2012a). Although unlikely
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given the conditions of use, EPA expects to consider vapor intrusion as a pathway of exposure for the
general population.
Based on these potential sources and pathways of exposure, EPA expects to consider inhalation
exposures of the general population to air containing carbon tetrachloride in air that may result from
the conditions of use of carbon tetrachloride.
Oral
Oral ingestion pathways may include exposure to contaminated drinking water or breast milk. EPA also
expects to consider ingestion via the oral route such as from incidental ingestion of carbon
tetrachloride residue on the hand/body.
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 of carbon tetrachloride.
Dermal
Dermal exposure via water could occur through contact, such as washing and bathing with household
water contaminated with carbon tetrachloride. The source of the contaminated water could either be
contaminated surface or ground waters.
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 of carbon tetrachloride.
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 non-users.
• Consumers and bystanders associated with consumer use. Carbon tetrachloride has been
identified as being used in products available to consumers; however, only some individuals
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
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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. 2006).
In summary, in the risk evaluation for carbon tetrachloride, 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 carbon tetrachloride, as
described in the Strategy for Conducting Literature Searches for Carbon Tetrachloride: Supplemental
File for the TSCA Scope Document (EPA-HQ-OPPT-2( ). Based on initial screening, EPA expects
to consider the hazards of carbon tetrachloride 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 carbon
tetrachloride: ECHA (ECHA. 2017) and OECD SIPS Initial Assessment Profile (SIAP) t'OECD. 2011).
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 carbon tetrachloride (Carbon tetrachloride (CASRN 56-23-5) Bibliography: Supplemental
File for the TSCA Scope Document, EPA-HQ-C ).
EPA expects to consider the hazards of carbon tetrachloride to aquatic organisms including fish,
aquatic invertebrates, aquatic plants, sediment invertebrates and amphibians exposed to relevant
media under acute and chronic exposure conditions. In 2011, the OECD SIDS SIAP for carbon
tetrachloride summarized acute toxicity to fish and aquatic invertebrates from carbon tetrachloride,
based on mortality and immobilization, respectively. Chronic toxicity to aquatic invertebrates (growth
and reproduction) was observed when exposed to carbon tetrachloride. Aquatic plant toxicity was
observed, based on growth rate, when exposed to carbon tetrachloride. Embryo-larval mortality was
observed in different species of amphibians when exposed acutely to carbon tetrachloride.
EPA expects to consider the hazards of carbon tetrachloride to terrestrial organisms including soil
invertebrates and mammals exposed to relevant media under acute and chronic exposure conditions
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(see Carbon tetrachloride (CASRN 56-23-5) Bibliography: Supplemental File for the TSCA Scope
Document, IE PA- IH Q-0 IP PT-2.016-07 33).
2,4,2 Human Health Hazards
Carbon tetrachloride has an existing EPA IRIS Assessment (U.S. EPA. 2010) and an ATSDR Toxicological
Profile (ATSDR, 2005); hence, many of the hazards of carbon tetrachloride 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 carbon tetrachloride (Carbon tetrachloride (CASRN 56-23-5)
Bibliography: Supplemental File for the TSCA Scope Document, EPA-HQ-QPPT-2C ). EPA expects
to consider all potential hazards associated with carbon tetrachloride. 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
Following acute exposures, human case reports identify liver as a primary target organ of toxicity and
the kidney as an additional primary target organ of toxicity (U.S. EPA. 2010). Neurotoxicity indicated
central nervous system (CNS) depression is another primary effect of carbon tetrachloride in humans
following acute exposures, with examples of neurotoxic effects including drowsiness, headache,
dizziness, weakness, coma and seizures (U.S. EPA. 2010). Gl symptoms such as nausea and vomiting,
diarrhea and abdominal pain are considered another initial acute effect.
Liver Toxicity
Liver toxicity has consistently been demonstrated following human and animal exposures to carbon
tetrachloride (U.S. EPA. 2010). Suggestive evidence of an effect of occupational exposure on serum
enzymes indicative of hepatic effects was reported in a cross-sectional epidemiology study. Similar to
humans, data from acute, subchronic and chronic animal studies suggest that the liver is the major
target organ for carbon tetrachloride toxicity (U.S. EPA. 2010).
Kidney Toxicity
Renal toxicity is generally delayed relative to hepatotoxicity and effects include oliguria, elevated blood
urea nitrogen (BUN) and histopathological changes (e.g., nephrosis, degeneration and interstitial
inflammation in fatal cases). In animals, renal toxicity was observed in inhalation (but not oral) studies.
In subchronic studies, renal toxicity generally occurred at higher concentrations than those producing
liver damage. In contrast, chronic exposures resulted in comparable sensitivity of the kidney and liver
in rodents (U.S. EPA. 2010).
Irritation/Sensitization
Following dermal exposures, primary irritation was observed in rabbits and guinea pigs (ATSDR. 2005).
Guinea pigs also exhibited degenerative change in epidermal cells and edema (ATSDR. 2005). In the
murine local lymph node assay, carbon tetrachloride showed weak dermal sensitization potential
(OECD. 2011).
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2.4.2.2 Genotoxicity and Cancer Hazards
The IRIS Assessment for carbon tetrachloride evaluated data for genotoxicity and cancer hazard.
Carbon tetrachloride has been extensively studied for its genotoxic and mutagenic effects. Overall,
results are largely negative. There is little direct evidence that carbon tetrachloride induces intragenic
or point mutations in mammalian systems. The mutagenicity studies that have been performed using
transgenic mice have yielded negative results, as have the vast majority of the mutagenicity studies
that have been conducted in bacterial systems. The weight of evidence suggests that carbon
tetrachloride is more likely an indirect mutagenic agent (i.e., lipid peroxidation, protein modifications)
rather than a direct mutagen (deoxyribonucleic acid [DNA] modifications) (U.S. EPA. 2010).
In the IRIS carcinogenicity assessment, carbon tetrachloride is considered "likely to be carcinogenic to
humans" by all routes of exposure based on inadequate evidence of carcinogenicity in humans, and
sufficient evidence in animals by oral and inhalation exposure. The animal evidence shows that carbon
tetrachloride is a liver carcinogen in rats, mice and hamsters following oral and inhalation exposure in
eight bioassays. Carbon tetrachloride also induced pheochromocytomas in mice exposed by the oral
and inhalation routes of exposure.
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
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).
EPA's IRIS assessment identified the following as factors that might influence susceptibility to carbon
tetrachloride: age (e.g., childhood, senescence), gender, nutritional status, disease status and exposure
to other chemicals (U.S. EPA. 2010, 2006). The IRIS assessment noted that because metabolism of
carbon tetrachloride to reactive metabolites by cytochrome P450 (CYP450) enzymes is hypothesized to
be a key event in the toxicity of this compound, variability in CYP450 levels due to age-related
differences or other factors such as exposure to other chemicals that either induce or inhibit
microsomal enzymes may impact an individual's response to carbon tetrachloride. In addition,
variability in nutritional status, alcohol consumption and/or underlying diseases (e.g., diabetes) may
alter metabolism or antioxidant protection systems and thereby also alter susceptibility to carbon
tetrachloride (U.S. EPA. 2010). EPA expects to consider these factors, and others that may be identified
from more current literature, in the risk evaluation for carbon tetrachloride.
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
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the conditions of use, exposures (pathways and routes), hazards and receptors. As part of the scope for
carbon tetrachloride, 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 carbon tetrachloride. EPA expects that workers and occupational non-users may
be exposed to carbon tetrachloride via inhalation and dermal routes. EPA expects to consider potential
worker exposure through mists that deposit in the upper respiratory tract and are swallowed.
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INDUSTRIAL AND COMMERCIAL
activities / USES
EXPOSURE PATHWAY
EXPOSURE ROUTE
RECEPTORS ef
HAZARDS
Manufacturing
Processing:
* As reactant/
intermediate
* Incorporated into
formulation, mixture, or
reaction product
* incorporated into article
* Repackaging
Recycling
Petrochemical and
Agricultural Products
Manufacturing
Solvents for Cieamngand
Degreasmg*
Adhessves and Sealants*
Paints and Coatings*
Laboratory Chemicals *
fc Liquid Contact
Dermal
Workers
Occupational
Non-Users
Inhalation
Vapor/ Mist
Fugitive
Emissions
Outdoor Air
(See Figure 2-4 for
Emissions to Air)
Hazards Potentially Associated with
Acute and/or Chronic Exposures
See Section 2.4.2
Stack
Emissions b
w
Air Pollution Control
Waste Handling,
Treatment and Disposal
4
X Workers
Occupational
Non-Users
Liquid Contact, Vapor
Derma?, inhalation
Wastewater, Liquid Wastes, Solid Wastes
(See Figure 2-4)
Figure 2-2. Initial Carbon Tetrachloride 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 carbon tetrachloride.
aSome products are used in both commercial and consumer applications. Additional uses of carbon tetrachloride are included in Table 2-3.
bStack 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, open-ended lines; evaporative losses from
surface impoundment and spills; and releases from building ventilation systems.
c Includes possible vapor intrusion into industrial or commercial facility from carbon tetrachloride contaminated soil and/or ground water.
d Exposure through mists that deposit in the upper respiratory tract and are swallowed.
e Receptors include potentially exposed or susceptible subpopulations.
fWhen 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 carbon
tetrachloride. Similar to Figure 2-2, EPA expects that consumers and bystanders may be exposed via
inhalation, dermal and oral routes, with inhalation of vapor and mist and dermal exposures being the
most likely exposure routes. It should be noted that some consumers may purchase and use products
primarily intended for commercial use. It also shows liquid and solid wastes containing carbon
tetrachloride.
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CONSUMER ACTIVITIES / USES3 EXPOSURE PATHWAY EXPOSURE ROUTE RECEPTORSc HAZARDS
Consumers,
Bystanders
Consumers,
Bystanders
Dermal
Oralb
Vapor, Liquid Contact
Liquid Contact
Vapor/Mist
Inhalation
Laboratory Chemicals
Paints and Coatings
Adhesives and Sealants
Other Uses
Dermal, Oralb,
Inhalation
Consumer Handling and Disposal
of Waste
Solvents for Cleaning and
Degreasing
e.g., textile cleaning, brake
cleaning
Hazards Potentially Associated with
Acute and/or Chronic Exposurese
See Section 2.4.2
Wastewater, Liquid Wastes, Solid Wastes
(See Figure 2-4)
Figure 2-3. Initial Carbon Tetrachloride 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 carbon tetrachloride.
a Some products are used in both commercial and consumer applications. Additional uses of carbon tetrachloride are included in Table 2-3.
b EPA expects to consider potential exposure through 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 carbon tetrachloride residue on the hand/body.
c Receptors include potentially exposed or susceptible subpopulations.
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2,53 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 carbon tetrachloride may be exposed via inhalation of outdoor air. In addition, aquatic
and terrestrial life may be exposed to carbon tetrachloride-contaminated water, sediment and soil.
Exposures to ecological species from releases of carbon tetrachloride to environmental media and
disposal of wastes containing carbon tetrachloride are depicted in Figure 2-4.
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RELEASE AND WASTES FROM
INDUSTRIAL/COMMERCIAL/CONSUMER USES
EXPOSURE PATHWAY
EXPOSURE ROUTE
RECEPTORS £
HAZARDS
Wastewater or
Liquid Wastes
Solid Wastes
Liquid Wastes
Emissions to Air
Municipal,
Hazardous Landfill
or Other Land
Disposal
Incinerators
(Municipal &
Hazardous Waste)
Recycling, Other
Treatment13
Direct
Industrial Pre-
Treatmentor
Industrial WWT
discharge
Water
Sediment
Aquatic
Species
Indirect discharge
Oral
Dermal. Inhalation
Bioso ids
POTW
Underground
Injection
j/ General \
Ground
water
Inhalationd
Indoor/
Outdoor
Air
Terrestrial
Species
Potential Hazards Associated
with Acute and Chronic
Exposures
See Section 2.4.1
Potential Hazards Associated
with Acute and Chronic
Exposures
See Section 2.4.2
Off-site Waste
Transfer
Waste Transport ^
Human Health Pathway
Ecological Pathway
Potential Hazards Associated
with Acute and Chronic
Exposures
See Section 2.4.1
Figure 2-4. Initial Carbon Tetrachloride 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 carbon tetrachloride.
a Industrial wastewater or liquid wastes may be treated on-site and then released to surface water (direct discharge), or pre-treated and released to publicly owned
treatment works (POTW) (indirect discharge). For consumer uses, such wastes 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 exposure 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 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 of carbon tetrachloride, 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 Carbon tetrachloride (CASRN 56-23-5) Bibliography: Supplemental File
for the TSCA Scope Document (IE IP A- IH Q-Q IP IFT-2016-0733). The analysis plan will be expanded if EPA
identifies additional hazards, exposures, conditions of use or potentially exposed or susceptible
subpopulations that are relevant to this risk evaluation. 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 National Emissions Inventory [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 carbon
tetrachloride:
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. Availabe
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 extent 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 the 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 carbon tetrachloride.
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 carbon tetrachloride 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. 2000). As defined in the 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. 2000). EPA will also
present information in this section consistent with approaches described in the Risk Evaluation
Framework Rule.
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[EPA Report]. Washington, DC: Office of Drinking Water.
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characterization (pp. 1-189). (EPA/100/B-00/002). Washington, D.C.: U.S. Environmental
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(CAS No. 56-23-5) in support of summary information on the Integrated Risk Information
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U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics.
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processing, distribution, use, and disposal: Carbon tetrachloride. Washington, DC.
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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(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.
Carbon tetrachloride 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.
Carbon tetrachloride 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.
Carbon tetrachloride 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, importers and
(if specified) processors of a chemical
substance or mixture to submit lists
and/or copies of health and safety
studies.
Two submissions received (1947-
1994) (U.S. EPA, ChemView.
Accessed April 13, 2017).
TSCA - Section 8(e)
Manufacturers (including imports),
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.
Three submissions received (1992-
2010) (U.S. EPA, ChemView.
Accessed April 13, 2017).
TSCA - Section 4
Provides EPA with authority to issue
rules and orders requiring
Seven section 4 notifications
received for carbon tetrachloride:
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
manufacturers (including importers) and
processors to test chemical substances
and mixtures.
two acute aquatic toxicity studies,
one bioaccumulation report and
four monitoring reports (1978-1980)
(U.S. EPA, ChemView. Accessed
April 13, 2017).
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.
Carbon tetrachloride is a listed
substance subject to reporting
requirements under 40 CFR 372.65
effective as of January 1,1987.
Federal Insecticide,
Fungicide, and
Rodenticide Act
(FIFRA) - Sections 3
and 6
FIFRA governs the sale, distribution and
use of pesticides. Section 3 of FIFRA
generally requires that pesticide
products be registered by EPA prior to
distribution or sale. Pesticides may only
be registered if, among other things,
they do not cause "unreasonable
adverse effects on the environment."
Section 6 of FIFRA provides EPA with the
authority to cancel pesticide
registrations if either (1) the pesticide,
labeling, or other material does not
comply with FIFRA; or (2) when used in
accordance with widespread and
commonly recognized practice, the
pesticide generally causes unreasonable
adverse effects on the environment.
Use of carbon tetrachloride as a
grain fumigant was banned under
FIFRA in 1986(51 FR 41004,
November 12, 1986).
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 determine that the
tolerance or exemption is "safe."
Sections 408(b) and (c) of the FFDCA
define "safe" to mean the Agency has a
EPA removed carbon tetrachloride
from its list of pesticide product
inert ingredients used in pesticide
products in 1998 (63 FR 34384, June
24, 1998).
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
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.
CAA - Section 112(b)
This section lists 189 HAPs that must be
addressed by EPA and includes authority
for EPA to add or delete pollutants. EPA
may, by rule, add pollutants that
present, or may present, a threat of
adverse human health effects or
adverse environmental effects.
Lists carbon tetrachloride as a HAP
(70 FR 75047, December 19, 2005).
CAA - Section 112(d)
Directs EPA to establish, by rule,
NESHAPs for each category or
subcategory of major sources and area
sources of HAPs. The standards must
require the maximum degree of
emission reduction that EPA determines
is achievable by each particular source
category. This is generally referred to as
maximum achievable control technology
(MACT).
There are a number of source-
specific NESHAPs for carbon
tetrachloride, including:
Rubber tire manufacturing (67 FR
45588, July 9, 2002)
Chemical Manufacturing Area
Sources (74 FR 56008, October 29,
2009)
Use of carbon tetrachloride as a
dilutent for NCI3 (59 FR 19402, April
22,1994),
Halogenated solvent cleaning
operations (59 FR 61801, December
2, 1994)
Wood Furniture Manufacturing
Operations (60 FR 62930, December
7,1995)
Group 1 Polymers and Resins (61 FR
46906, September 5, 1996)
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
Plywood and Composite Wood
Products (69 FR 45944, July 30,
2004)
CAA - Section 604
Establishes a mandatory phase-out of
ozone depleting substances.
The production and import of most
Class 1 Ozone Depleting Substances
(ODS), including carbon
tetrachloride, was banned in 1996
(58 FR 65018, December 10, 1993).
However, this ban does not apply to
production and import of amounts
that are transformed. 40 CFR 82.4.
"Transform" is defined as "to use
and entirely consume (except for
trace quantities) a controlled
substance in the manufacture of
other chemicals for commercial
purposes." 40 CFR 82.3.
CWA - Section
304(a)(1)
Requires EPA to develop and publish
ambient water quality criteria (AWQC)
reflecting the latest scientific knowledge
on the effects on human health that
may be expected from the presence of
pollutants in any body of water.
In 2015, EPA published updated
AWQC for carbon tetrachloride,
including recommendations for
"water + organism" and "organism
only" human health criteria for
states and authorized tribes to
consider when adopting criteria into
their water quality standards.
CWA - Sections
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 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.
CWA - Section 307(a)
Establishes a list of toxic pollutants or
combination of pollutants under the
CWA. The statute specifies a list of
families of toxic pollutants also listed in
the Code of Federal Regulations at 40
CFR 401.15. The "priority pollutants"
specified by those families are listed in
Carbon tetrachloride is designated
as a toxic pollutant under section
307(a)(1) of the CWA and as such is
subject to effluent limitations per
section 1317 of the Clean Water
Act.
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
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, see section 301(b),
304(b), 307(b), 306, or on a case-by-case
best professional judgment basis in
NPDES permits. CWA 402(a)(1)(B).
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 judgment of the Administrator,
regulation of the contaminant presents
a 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.
Carbon tetrachloride is subject to
National Primary Drinking Water
Regulations (NPDWR) under SDWA
and EPA has set a MCLG of zero and
an enforceable MCL of 0.005 mg/L
(56 FR 3526 January 30,1991).
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
Carbon tetrachloride is a hazardous
substance under CERCLA. Releases
of carbon tetrachloride in excess of
10 pounds must be reported (40
CFR 302.4).
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
have knowledge of a release of a
hazardous substance above the
reportable quantity threshold.
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 in
tissue, and other related factors such as
flammability, corrosiveness, and other
hazardous characteristics.
Carbon tetrachloride is included on
the list of hazardous wastes
pursuant to RCRA 3001. Two
categories of carbon tetrachloride
wastes are considered hazardous:
discarded commercial chemicals
(U211) (40 CFR 261.31(a)), and
spent degreasing solvent (F001) (40
CFR 261.33(f)) (45 FR 33084 May 19,
1980).
RCRA solid waste that leaches
0.5 mg/L or more carbon
tetrachloride when tested using the
TCLP leach test is RCRA hazardous
(D019) under 40 CFR 261.24 (55 FR
11798 March 29, 1990).
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
(40 CFR 261.4(a)(26)) (78 FR 46447,
July 31, 2013).
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.
Use of carbon tetrachloride in
consumer products was banned in
1970 by the CPSC (16 CFR 1500.17).
FFDCA
Provides the U.S. Food and Drug
Administration (FDA) with authority to
The FDA regulates carbon
tetrachloride in bottled water. The
maximum permissible level of
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Statutes/Regulations
Description of Authority/Regulation
Description of Regulation
oversee the safety of food, drugs and
cosmetics.
carbon tetrachloride in bottled
water is 0.005 mg/L (21 CFR
165.110).
All medical devices containing or
manufactured with carbon
tetrachloride must contain a
warning statement that the
compound may destroy ozone in
the atmosphere (21 CFR 801.433).
Carbon tetrachloride is also listed as
an "Inactive Ingredient for approved
Drug Products" by FDA (FDA Inactive
Ingredient Database. Accessed April
13, 2017).
OSHA
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.
In 1970, OSHA issued occupational
safety and health standards for
carbon tetrachloride that included a
PEL of 10 ppm TWA, exposure
monitoring, control measures and
respiratory protection (29 CFR
1910.1000).
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.
OSHA prohibits all workplaces from
using portable fire extinguishers
containing carbon tetrachloride (29
CFR 1910.157(c)(3)).
Atomic Energy Act
The Atomic Energy Act authorizes the
Department of Energy to regulate the
health and safety of its contractor
employees.
10 CFR 851.23, Worker Safety and
Health Program, requires the use of
the 2005 ACGIH TLVs if they are
more protective than the OSHA PEL.
The 2005 TLV for carbon
tetrachloride is 5 ppm (8hrTime
Weighted Average) and 10 ppm
Short Term Exposure Limit (STEL).
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A,2 State Laws and Regulations
Table_Apx A-2. State Laws and Regulations
State Actions
Description of Action
State agencies of interest
State permissible exposure limits
California PEL: 12.6 mg/L (Cal Code Regs. Title 8,
section 5155), Hawaii PEL: 2 ppm (Hawaii
Administrative Rules section 12-60-50).
State Right-to-Know Acts
Massachusetts (454 Code Mass. Regs, section 21.00),
New Jersey (8:59 N.J. Admin. Code section 9.1),
Pennsylvania (34 Pa. Code section 323).
State air regulations
Allowable Ambient Levels (AAL): Rhode Island (12 R.I.
Code R. 031-022), New Hampshire (RSA 125-1:6, ENV-
AChap. 1400).
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).
Other
In California, carbon tetrachloride was added to the
Proposition 65 list in 1987 (Cal. Code Regs. Title 27,
section 27001).
Carbon tetrachloride is on the MA Toxic Use
Reduction Act (TURA) list of 1989 (301 Code Mass.
Regs, section 41.03).
A.3 International Laws and Regulations
Table_Apx A-3. Regulatory Actions by Other Governments and Tribes
Country/Organization
Requirements and Restrictions
Regulatory Actions by other Governments and Tribes
Montreal Protocol
Carbon tetrachloride is considered an ODS and its production and use are
controlled under the 1987 Montreal Protocol on Substances That Deplete
the Ozone Layer and its amendments (Montreal Protocol Annex B - Group
II).
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Country/Organization
Requirements and Restrictions
Canada
Carbon tetrachloride is on the Canadian List of Toxic Substances (CEPA
1999 Schedule 1). Other regulations include:
Federal Halocarbon Regulations, 2003 (SOR/2003-289).
ODS Regulations, 1998 (SOR/99-7).
European Union (EU)
Carbon tetrachloride was evaluated under the 2012 Community rolling
action plan (CoRAP) under regulation (European Commission [EC]) No
1907/2006 - REACH (Registration, Evaluation, Authorisation and
Restriction of Chemicals) ECHA database. Accessed April 18, 2017).
Carbon tetrachloride is restricted by regulation (EC) No 2037/2000 on
substances that deplete the ozone layer.
Australia
Carbon tetrachloride was assessed under Environment Tier II of the
Inventory Multi-Tiered Assessment and Prioritisation (IMAP), and there
have been no reported imports of the chemical as a feedstock in the last
10 years (National Industrial Chemicals Notification and Assessment
Scheme, NICNAS, 2017, Environment Tier II Assessment for Methane,
Tetrachloro-. Accessed April, 18 2017).
Japan
Carbon tetrachloride is regulated in Japan under the following
legislation:
• Industrial Safety and Health Act (ISHA)
• 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
• Poisonous and Deleterious Substances Control Act
• Act on the Protection of the Ozone Layer through the Control of
Specified Substances and Other Measures
• 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 13, 2017).
Australia, Austria,
Belgium, Canada,
Denmark, EU, Finland,
France, Germany, Ireland,
Israel, Japan, Latvia, New
Zealand, People's
Republic of China,
Poland, Singapore, South
Occupational exposure limits (OELs) for carbon tetrachloride. (GESTIS
International limit values for chemical agents (Occupational exposure
limits, OELs) database. Accessed April 18, 2017).
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Country/Organization
Requirements and Restrictions
Korea, Spain, Sweden,
Switzerland, United
Kingdom
Basel Convention
Halogenated organic solvents (Y41) are listed as a category of waste under
the Basel Convention-Annex 1. Although the United States is not currently
a party to the Basel Convention, this treaty still affects U.S. importers and
exporter.
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.
Appendix B PROCESS, RELEASE AND OCCUPATIONAL EXPOSURE
INFORMATION
This appendix provides information and data found in preliminary data gathering for carbon
tetrachloride.
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 for consideration.
B.l.l Manufacture (Including Import)
B.l.1.1 Domestic Manufacture
Carbon tetrachloride was previously produced solely through the chlorination of carbon disulfide (CS2);
however, in the 1950s chlorination of hydrocarbons became popular (Holbrook, 2000). Currently, most
Carbon tetrachloride is manufactured using one of three methods: chlorination of hydrocarbons or
chlorinated hydrocarbons; oxychlorination of hydrocarbons; or CS2 chlorination (Holbrook. 2000).
• Chlorination of hydrocarbons or chlorinated hydrocarbons - The chlorination of hydrocarbons
involves a simultaneous breakdown of the organics and chlorination of the molecular fragments
at pyrolytic temperatures and is often referred to as chlorinolysis) (Holbrook. 2000). A variety of
hydrocarbons and chlorinated hydrocarbon waste streams can be used as feedstocks; however,
methane is the most common (Holbrook. 2000). PCE is formed as a major byproduct of this
process with small volumes of hexachloroethane, hexachlorobutadiene and hexachlorobenzene
also produced (Holbrook. 2000).
• Oxychlorination of hydrocarbons - The oxychlorination of hydrocarbons involves the reaction
of either chlorine or hydrochloric acid (HCI) and oxygen with a hydrocarbon feedstock in the
presence of a catalyst (Marshall and Pottenger, 2016; Holbrook. 2000). This process can be
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utilized to convert HCI produced as a byproduct during the manufacture of chlorinated
hydrocarbons into useful products (Marshall and Pottenger, 2016).
• CS2 Chlorination - The chlorination of CS2 involves the continuous reaction of CS2 with chlorine
in an annular reaction (Holbrook, 2000). The carbon tetrachloride produced is distilled to have a
CS2content of 0 to 5 ppm. This process produces disulfur dichloride as a byproduct that is
reduced with hydrogen without a catalyst or with a ferric chloride catalyst (Holbrook, 2000).
Based on EPA's knowledge of the chemical industry, worker activities at manufacturing facilities may
involve manually adding raw materials or connecting/disconnecting transfer lines used to unload
containers into storage or reaction vessels, rinsing/cleaning containers and/or process equipment,
collecting and analyzing QC samples, manually loading carbon tetrachloride product or
connecting/disconnecting transfer lines used to load carbon tetrachloride product into containers.
B.l.1.2 Import
EPA has identified activities related to the import of carbon tetrachloride through comments submitted
in public docket IE PA-HI' 116-0733. Based on EPA's knowledge of the chemical industry,
imported chemicals are often stored in warehouses prior to distribution for further processing and use.
In some cases, the chemicals may be repackaged into differently sized containers, depending on
customer demand, and QC samples may be taken for analyses.
B.1.2 Processing and Distribution
B.1.2.1 Reactant or Intermediate
Processing as a reactant or intermediate is the use of carbon tetrachloride as a feedstock in the
production of another chemical product via a chemical reaction in which carbon tetrachloride is
consumed to form the product. In the past, carbon tetrachloride was mainly used as feedstock for the
manufacture chlorofluorocarbons (CFCs) (Marshall and Pottenger, 2016). However, due to the
discovery that CFCs contribute to stratospheric ozone depletion, the use of CFCs was phased-out by
the year 2000 to comply with the Montreal Protocol (Holbrook, 2000).
Currently, carbon tetrachloride is used as a feedstock to produce a variety of products including HCFCs,
HFCs, HFOs, vinyl chloride, ethylene dichloride (EDC), PCE, chloroform, hafnium tetrachloride,
thiophosgene and methylene chloride (EPA-HQ-QPPT-2016-0733-0003) (U.S. EPA, 20 Marshall and
Pottenger, 2016; Weil et al., 2006; Holbrook, 2003a, b). The specifics of the reaction process (e.g., use
and types of catalysts, temperature conditions, etc.) will vary depending on the product being
produced; however, a typical reaction process would involve unloading carbon tetrachloride from
containers and feeding into the reaction vessel(s), where carbon tetrachloride would either fully or
partially react with other raw materials to form the final product. Following the reaction, the product
may or may not be purified to remove unreacted carbon tetrachloride (if any exists). Reacted carbon
tetrachloride is assumed to be destroyed and thus not expected to be released or cause potential
worker exposure.
EPA has not identified specific worker activities related to the processing of carbon tetrachloride as a
reactant or intermediate at this time. However, based on EPA's knowledge of the chemical industry,
worker activities are expected to be similar to that at manufacturing facilities including unloading and
loading activities, rinsing/cleaning activities and collecting and analyzing QC samples.
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B.l.2.2 Incorporation into a Formulation, Mixture or Reaction Products
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 carbon
tetrachloride that may require incorporation into a formulation include adhesives, sealants, paints,
coatings, additives and asphalt. Carbon tetrachloride specific formulation processes were not
identified; however, several ESDs published by OECD and Generic Scenarios published by EPA have
been identified that provide general process descriptions for 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).
Process descriptions for formulation of sealants, additives and asphalt were not identified at this time.
However, the processes are expected to be similar to those described above and typically involve
unloading formulation components from transport containers, either directly into the mixing
equipment or into an intermediate storage vessel, mixing of components either a batch or continuous
system, QC sampling and final packaging of the formulation in to containers. Depending on the
product, formulation products may be filtered prior to packaging. Transfer from transport containers
into storage or mixing vessels may be manual or automated, through the use of a pumping system. If
automated, an automated dispenser may be used to feed the components into the mixing vessel to
ensure that precise amounts are added at the proper time during the mixing process. Final packaging
occurs either through manual dispensing from transfer lines or through utilization of an automatic
system.
There is significant overlap in worker activities across the various formulation processes. The activities
are expected to be similar to manufacturing activities and include unloading and loading activities,
rinsing/cleaning activities and collecting and analyzing QC samples (C 009a. b).
B.l.2.3 Incorporation into an Article
Incorporation into an article typically refers to a process in which a chemical becomes an integral
component of an article (as defined at 40 CFR 704.3) that is distributed for industrial, trade or
consumer use. Exact process operations involved in the incorporation of carbon tetrachloride are
dependent on the article. EPA will further investigate the potential use of carbon tetrachloride in this
type of process during the risk evaluation.
B.1.2.4 Repackaging
Typically, 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. Based on
EPA's knowledge of the chemical industry, worker activities at repackaging sites may involve manually
unloading carbon tetrachloride from bulk containers into the smaller containers for distribution or
connecting/disconnecting transfer lines used to transfer carbon tetrachloride product between
containers and analyzing QC samples. EPA will further investigate the potential use of carbon
tetrachloride in this type of process during the risk evaluation.
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B.1.2.5 Recycling
TRI data from 2015 indicate that some sites ship carbon tetrachloride 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).
Worker activities are expected to be unloading of waste solvents and loading of reclaimed solvents.
Figure_Apx B-l illustrates a typical solvent recovery process flow diagram (U.S. EPA. 1980).
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Storage
and
Handling
and r
Handling
Incinerator Stack
Waste
Figure_Apx B-l. General Process Flow Diagram for Solvent Recovery Processes
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B.1.3 Uses
In this document, EPA has grouped uses based on CDR categories and identified examples within these
categories as subcategories of use. 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 Petrochemical Manufacturing
EPA has identified uses of carbon tetrachloride as a processing aid and in catalyst regeneration at
petrochemical manufacturing facilities rEPA~HQ~OPPT~2016~0733~0003 (U.S. EPA. 2 )]. EPA has also
identified a patent which indicates a potential use of carbon tetrachloride as a fuel additive.
B.1.3.2 Agricultural Products Manufacturing
EPA has identified uses of carbon tetrachloride in the manufacturing of fertilizers and other agricultural
products [EPA-HQ-OPPT-2016-0733-0003 (U.S. EPA. 2017c)l.
B.1.3.3 Solvents for Cleaning and Degreasing
Carbon tetrachloride has been identified in a variety of cleaning products including brake cleaners,
machinery cleaning products and textile cleaning products rEPA~HQ~OPPT~2016~0733~0003 (U.S. EPA.
2] )]. Due to the Montreal Protocol and Title VI of the CAA Amendments, use of carbon
tetrachloride in these types of products has been phased-out. Because most of the products identified
by EPA in the Preliminary Information on Manufacturing, Processing, Distribution, Use, and Disposal:
Carbon Tetrachloride rEPA~HQ~OPPT~2016~0733~0003 (U.S. EPA. 2017c)l contain less than 1% by weight
carbon tetrachloride and CAA regulations, EPA expects carbon tetrachloride is only present in these
products as an impurity rather than serving a specific function.
Brake Cleaning
Brake cleaners are typically aerosol degreasing products in which an aerosolized solvent spray, typically
applied from a pressurized can, is used to remove residual contaminants from fabricated parts. General
aerosol degreasing processes, including brake cleaning, have been previously described in ;
Draft Risk Assessment (U.S. EPA. 2016c). Brake cleaning products may also be purchased and used by
consumers.
Textile Cleaning
Textile cleaning typically refers to the use as a solvent in dry cleaning machines or in products used to
spot clean garments. 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-BP Draft Risk Assessment (U.S. EPA. 2016c).
Machinery Cleaning
Machinery cleaning could fall under a variety of degreasing operations that are used to remove dirt,
grease and surface contaminants from the substrate. Degreasing operations can involve batch
processes, continuous processes or aerosol degreasing (similar to that of brake cleaning); actual
operation can include vapor-phase and/or liquid-phase degreasing (e.g. cold cleaning) EPA's 1-BP Draft
Risk Assessment (U.S. EPA. 2016c).
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B.l.3.4 Adhesive and Sealants
Carbon tetrachloride has been identified as a component in several adhesive and sealant products and
in asphalt rEPA~HQ~OPPT~2016~0733~0003 (U.S. EPA. 2i )]. Similar to cleaning and degreasing
solvents, the use of carbon tetrachloride in these products was phased-out and most of the products
identified by EPA contain less than 1% by weight carbon tetrachloride. Therefore, EPA expects carbon
tetrachloride is only present in these formulations as an impurity rather than serving a specific function
(E PA-HQ-0 IP PT-2016-0733).
The OECD ESD for Use of Adhesives provides general process descriptions and worker activities for
industrial uses of adhesives. In industrial processes, liquid adhesives are unloaded from containers into
the coating reservoir, applied to a flat or three-dimensional substrate and the substrates are then
joined and allowed to cure (OECD, 2013). The majority of adhesive applications include spray, roll,
curtain, syringe or bead application (OECD, 2013). For solvent-based adhesives, the volatile solvent
evaporates during the curing stage (OECD, 2013). Worker activities include unloading activities,
container and equipment cleaning activities, and manual applications of adhesive (OECD. 2013). EPA
did not identify any process information for use in sealants or asphalt. EPA will gather additional
information in expanded literature searches in subsequent phases of the risk evaluation process. Note:
Based on EPA's knowledge of the industry, EPA expects an overlap in process descriptions, worker
activities and application methods for use of sealant products.
EPA has also identified several sealant and adhesive products that contain carbon tetrachloride that
could be purchased for commercial uses or purchased online by consumers [EPA-HQ-QPPT-2016-0733-
0003 (U.S. EPA. 2017c)1. Based on EPA's knowledge of the industry, the likely application methods for
commercial and consumer uses include spray, brush, syringe, eyedropper, roller and bead applications.
B.l.3.5 Paints and Coatings
Carbon tetrachloride has been identified as a component in paint and coating products such as
swimming pool paints and traffic paints rEPA-HQ-OPPT-2016-0733-0003 (U.S. EPA. 2017c)l. Similar to
cleaning and degreasing solvents, the use of carbon tetrachloride in these products was phased-out
and most of the products identified by EPA contain less than 1% by weight carbon tetrachloride.
Therefore, EPA expects carbon tetrachloride is only present in these formulations as an impurity rather
than serving a specific function.
Several OECD ESDs and EPA generic scenarios provide general process descriptions and worker
activities for industrial and commercial uses od paints and coatings. Typical 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, 2009a, b). Worker activities are expected to include unloading
activities, container and equipment cleaning activities, and manual applications of coatings.
B.l.3.6 Laboratory Chemicals
Carbon tetrachloride is used in laboratories as a chemical reagent, extraction solvent and a reference
material or solvent in analytical procedures, such as spectroscopic measurements [EPA-HQ-QPPT-2016-
0733-0003 (U.S. EPA. 201 A.)].
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B.l.3.7 Other Uses
Carbon tetrachloride may also be used in a variety of other uses including reactive ion etching (RIE),
laboratory chemicals, processing aid and metal recovery. RIE involves ion bombardment to achieve
directional etching and a reactive gas, such as carbon tetrachloride, to selectively maintain etched
layers rEPA-HQ-QPPT-2016-0733-0003 (U.S. EPA. 201 i)].
B.1.4 Disposal
Table 2-5 and Table 2-6 present the production-related waste managed data for carbon tetrachloride
reported to the TRI program for 2015. Waste containing carbon tetrachloride is classified as hazardous
waste (see Table_Apx A-l). Facilities generating waste containing carbon tetrachloride must comply
with EPA regulations for treatment, storage, and disposal.
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 OSHA CEHD data by all of the North American Industry Classification
Systems (NAICS) codes.
Table_Apx B-l. Summary of Industry Sectors with Carbon Tetrachloride Personal Monitoring Air
Samples Obtained from OSHA Inspections Conducted Between 2013 and 2016
NAICS
North American
Industrial
Classification
System
NAICS Description
322121
Paper (except newsprint) mills
331512
Steel investment foundries
332439
Other metal container manufacturing
336111
Automobile manufacturing
926150
Regulation, licensing and inspection of miscellaneous commercial sectors
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