EPA proposes bans and restrictions on the use of carbon tetrachloride
Chemicals
| By PATRICIA ISCARO, ESQ.

The Environmental Protection Agency has issued a notice of proposed rulemaking banning six uses of carbon tetrachloride. The proposal allows for a workplace chemical protection program for remaining uses the manufacture, import, distribution, use, or disposal of carbon tetrachloride.
Identity and profile of carbon tetrachloride
- Carbon tetrachloride (CAS RN 56-23-5), has several synonyms: benziform, carbon chloride, carbon tet, methane tetrachloride, methane, tetrachloro-, methyl tetrachloride, perchloromethane, and tetrachloromethane. It is a colorless, sweet-smelling organic compound that is primarily used as a feedstock to manufacture hydrofluorocarbon (HFC) and hydrofluoroolefin (HFO) refrigerants, including HFC-245fa, HFC-365mfc (UNEP, 2016a) and HFO-1234yf/ze. Carbon tetrachloride has minor laboratory, petroleum refining, and pharmaceutical manufacturing applications.
- A solvent, carbon tetrachloride (CTC) is used in commercial settings as a raw material for producing other chemicals like refrigerants, chlorinated compounds, and agricultural products. Although it has a yearly reported production volume (manufacture and import) of about 117 million to 143 million pounds, production of carbon tetrachloride has continued to decline with the implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) and through the 1990 Clean Air Act amendments, which banned carbon tetrachloride’s emissive uses and phased out CFCs for all but explicitly permitted uses. In addition, CTC and mixtures containing it were banned from consumer products by the Consumer Product Safety Commission (CPSC) in 1970 due to its potential to cause adverse health effects.
- The Occupational Safety and Health Administration’s (OSHA) 2022 permissible exposure limits (PELs) sets a 10 parts per million (ppm) for an 8-hour Time Weighted Average (TWA), with a ceiling concentration of 25 ppm. However, this limit may not reflect the more current studies and may not adequately protect workers. OSHA’s acceptable maximum peak exposure is 200 ppm (maximum duration = 5 minutes in any 4 hours), and both California’s OSHA and NIOSH set a recommended limit of 2 ppm per 8 or 10 hour TWA, respectively. Carbon tetrachloride cannot be used as a fire extinguishing agent where employees may be exposed.
Regulation of CTC under TSCA
- On June 22, 2016, the “ Frank R. Lautenberg Chemical Safety for the 21st Century Act” was signed into law, amending the 1976 Toxics Substances Control Act. TSCA (section 6(b)), administered by EPA’s Office of Pollution Prevention and Toxics (OPPT), required EPA to initiate Risk Evaluations for 10 chemical substances drawn from the 2014 update of the TSCA Work Plan for Chemical Assessments. Going forward, TSCA imposed additional statutory requirements to ensure that Risk Evaluations and potential risk management rules continue on a rolling basis as the Risk Evaluations are completed.
- EPA evaluates hazard and exposure, using scientific information and approaches in a manner that is consistent with the requirements of TSCA for the best available science, and ensures decisions are based on the weight-of-scientific-evidence approach (excluding consideration of costs or other non-risk factors). In accordance with TSCA Section 6(b), if the EPA finds unreasonable risk under the conditions of use in any final Risk Evaluation, the EPA will address the risks by proposing actions within the required timeframe.
- According to the EPA’s 2020 Risk Evaluation for carbon tetrachloride, exposure is based on “potential central nervous system depression, which can lead to workplace accidents and which is a precursor to more severe central nervous system effects such as incapacitation, loss of consciousness, and death, as well as liver toxicity and cancer as sensitive endpoints.”
- EPA determined that 13 conditions of use of CTC present an unreasonable within the risk of injury to health, while two conditions of use do not present an unreasonable risk of injury to health or the environment (processing as a reactant/intermediate in reactive ion etching (i.e., semiconductor manufacturing), and distribution in commerce).
- EPA issued the Final Revision to the risk determination for the carbon tetrachloride risk evaluation on December 23, 2022. This revision superseded the condition of use-specific no unreasonable risk determinations of the 2020 CTC risk evaluation. The December 2022 final revision makes a determination of unreasonable risk as a two-pronged consideration for CTC as a whole chemical substance instead of determining unreasonable risks based on each individual condition of use (COU); which does not reflect an assumption that workers always have or wear personal protective equipment (PPE) properly. See this AgencyIQ analysis of the 2022 final revision to the risk determination for the CTC risk evaluation.
Now the EPA has unveiled a proposal to take regulatory action
- On July 13, EPA published a proposed rule regulating CTC under TSCA to address the unreasonable risk of injury to health, without consideration of costs or other non-risk factors, including an unreasonable risk to potentially exposed or susceptible subpopulations (PESS). Under the rule, EPA is proposing to prohibit certain industrial and commercial uses of CTC, and the manufacture (including import), processing, and distribution in commerce of CTC.
- For certain conditions of use that would not be subject to a prohibition, the EPA is proposing to require a CTC workplace chemical protection program (WCPP) that includes requirements to meet an inhalation exposure concentration limit and prevent direct dermal contact. For those uses, EPA is proposing monitoring, recordkeeping, and downstream notification requirements.
- EPA is not proposing any restrictions on the two conditions of use of CTC, processing as a reactant/intermediate in reactive ion etching (i.e., semiconductor manufacturing), and distribution in commerce as they do not drive the unreasonable risk. Additionally, EPA’s proposed regulatory action and primary alternative regulatory action include prohibitions on the distribution in commerce of CTC for certain downstream uses, but do not include any restrictions for the processing as a reactant/intermediate in reactive ion etching.
- Although EPA may grant an exemption from a requirement of a TSCA section 6(a) rule for a specific condition of use of a chemical substance or mixture (for example, if compliance with the requirement would significantly disrupt the national economy, national security, or critical infrastructure), EPA has found that a TSCA section 6(g) exemption is not warranted at this time and is not proposing to grant any specific exemptions from the rule requirements.
- EPA is also proposing to amend definitions for the regulation of chemicals substances and mixtures under section 6 of TSCA (40 CFR part 751, Subpart A) to define “authorized person,” “direct dermal contact,” “ECEL,” “exposure group,” “owner or operator,” “potentially exposed person,” and “regulated area” so that these definitions may be commonly applied to this and other rules under TSCA section 6 that would be codified under 40 CFR part 751.
- EPA has determined that the rule will not have a significant impact on a substantial number of small entities. EPA estimates that the rule would affect at least four small entities, and that the cost would only exceed 1% of annual revenues for one of these small entities.
EPA is proposing to prohibit the manufacturing, processing, distribution in commerce for certain uses of CTC. Here’s what this would look like in practice:
- EPA has not found any ongoing uses of CTC for these following conditions of use most likely due to the phaseout of CTC manufacturing in the U.S. for most non-feedstock domestic uses and is proposing their prohibition:
- Processing: Incorporation into formulation, mixture or reaction products in petrochemical-derived manufacturing
- Industrial and commercial use as a processing aid in the manufacture of petrochemical derived products
- Industrial and commercial use in the manufacture of other basic chemicals (including chlorinated compounds used in solvents, adhesives, asphalt, and paints and coatings), except for use in the elimination of nitrogen trichloride in the production of chlorine and caustic soda
- Industrial and commercial use in metal recovery
- Industrial and commercial use as an additive
- Manufacturing, processing, distribution in commerce, and use of CTC for the industrial and commercial use of CTC in specialty uses by the Department of Defense (DoD).
- The ban would take effect one year after publication of the final rule, indicating that this rule likely wouldn’t take effect until at least early 2025.
- Laboratory uses of CTC by the DoD would not be prohibited but would be regulated under industrial and chemical use of CTC as a laboratory chemical. Specific requirements would be applicable 180 days from the publication of the final rule for fume hoods and equipment. Advanced engineering controls would be required to be functioning properly one year from final rule publication, among other requirements.
- EPA believes that if these above listed uses are ongoing, they would occur in highly industrialized controlled a closed processes. In this case, EPA would propose a workplace chemical protection plan with monitoring and recordkeeping requirements. EPA is requesting comments on whether CTC is used for these proposed banned industrial and commercial uses.
Use of CTC for hydrofluorocarbons under the AIM Act of 2020
- EPA said it recognizes that CTC may assist in addressing climate damaging hydrofluorocarbons (HFCs). CTC is primarily used as a feedstock in the production of hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and hydrofluoroolefins (HFOs). This condition of use includes the use of CTC in closed reactors to make feedstocks, including refrigerants, aerosol propellants, and foam-blowing agents (e.g., HCFCs and HFCs), used to produce HFO.
- EPA’s response is to allow the use of CTC to address climate-damaging hydrofluorocarbons (HFCs) under the American Innovation and Manufacturing Act of 2020 (AIM Act) and the Kigali Amendment to the Montreal Protocol with additional worker protections. EPA explains that workplace controls can be implemented to address unreasonable risks of these HFC-related, reactant processing uses.
Proposed primary alternative regulatory actions
- As a result of EPA’s 2020 CTC risk evaluation and subsequent 2022 CTC risk determination, EPA is proposing to address the conditions of use that present unreasonable risks. For certain conditions of use that would not be subject to a prohibition, EPA is proposing to require a WCPP which would include requirements to meet an inhalation exposure concentration limit and prevent direct dermal contact. The WCPP also contains monitoring, recordkeeping, and downstream notification requirements.
- EPA is proposing to exclude from WCPP requirements for manufacturers those workplaces that manufacture CTC solely as a byproduct. In addition, EPA is assessing the manufacture of CTC as a byproduct during the manufacture of 1,2- dichloroethane in the risk evaluation for 1,2-dichloroethane.
- EPA is proposing a WCPP for manufacturing (including import) of CTC and the following other conditions of use which account for essentially all of the production volume of CTC manufactured annually:
- Processing as a reactant in the production of hydrochlorofluorocarbons (HCFCs) hydrofluorocarbon (HFCs), hydrofluoroolefin (HFOs) and perchloroethylene (PCE)
- Processing for incorporation into a formulation, mixture or reaction product in agricultural products manufacturing and other basic organic and inorganic chemical manufacturing
- Processing – repackaging for use in laboratory chemicals
- Processing – recycling
- Industrial and commercial use in the elimination of nitrogen trichloride in the production of chlorine and caustic soda
- Disposal
- EPA is asking for comments on the WCPP for the use of CTC in the production of HCFCs, HFCs, HFOs, and PCE including HFC-245fa, HFC-365mfc, and HFC-236fa and whether prescriptive controls, including respirators and dermal PPE, should be required for these uses.
WCPP
- The WCPP for the above listed uses would include an existing chemical exposure limit (ECEL) of 0.03 ppm as an 8-hour time-weighted average (TWA) to address risk from inhalation exposure in combination with Direct Dermal Contact Control (DDCC) requirements. Direct dermal contact means direct handling of a chemical substance or mixture or skin contact with surfaces that may be contaminated with a chemical substance or mixture. ECEL is an Existing Chemical Exposure Limit and means an airborne concentration generally calculated as an eight (8)-hour time-weighted average (TWA).
- The CTC ECEL is based on a 2007 study used to derive the EPA’s Integrated Risk Information System (IRIS) reference concentration for liver effects, which is more recent than the data OSHA had available when OSHA set the PEL for CTC in 1971. EPA is also proposing DDCC requirements for disposal of CTC.
- The WCPP would apply to the manufacturing (including import) of CTC and other conditions of use which account for essentially all of the production volume of CTC. EPA is also proposing to develop, in concert with industrial hygiene experts and industry, methodologies to measure CTC concentrations at or below the ECEL.
- The WCPP also includes monitoring and recordkeeping requirements to verify that the established inhalation thresholds are not exceeded, and may include other components, such as dermal protection, to ensure that the chemical substance no longer presents unreasonable risk.
- EPA uses the term “potentially exposed person” to include workers, occupational non-users, employees, independent contractors, employers, and all other persons in the work area where CTC is present and who may be exposed under the conditions of use for which a WCPP would apply.
- To ensure that potentially exposed persons in the workplace are informed of the hazards associated with CTC exposure, EPA is proposing to require that owners or operators of workplaces subject to an ECEL and DDCC requirements institute a training program for all potentially exposed persons. EPA is proposing to require implementation of a training program compatible with the OSHA Hazard Communication Standard (29 CFR 1910.1200) and similar to the OSHA General Industry Standard for Methylene Chloride (29 CFR 1910.1052). To ensure that potentially exposed persons in the workplace are informed of the hazards associated with CTC exposure, EPA is proposing to require that owners or operators of workplaces subject to the WCPP institute a training and information program for potentially exposed persons and ensure their participation in the training and information program.
- EPA is proposing to require specific prescriptive controls for the industrial and commercial use of CTC as a laboratory chemical with proposed requirements for a fume hood and dermal PPE for the industrial and commercial use of CTC as a laboratory chemical and advanced engineering controls specifically. These controls require dermal PPE, including impermeable gloves and protective clothing, in combination with comprehensive training for tasks particularly related to the use of CTC in a laboratory setting, among other requirements.
- These workplace controls are not the same as the proposed regulatory action since it requires dermal PPE along with training for direct handling of CTC rather than the use of elimination, substitution, engineering and administrative controls, along with the hierarchy of controls to control dermal exposures.
How EPA is thinking about CTC and Personal protective equipment (PPE)
- EPA is proposing to require implementation of a PPE program which would include training, in alignment with OSHA’s General Requirements for Personal Protective Equipment when all other controls (engineering, elimination, substitution, etc.) are not feasible. Respiratory and dermal protection would be required in keeping with EPA’s requirements set out in this proposal. Respirators would be required within three months after receipt of exposure monitoring indicating an exceedance of the ECEL or six months from publication of the final rule. EPA is also proposing that the owner or operator must ensure that all filters, cartridges and canisters used in the workplace are labeled and color coded with the NIOSH approval label in addition to other respiratory requirements in keeping with NIOSH requirements. Dermal protection program requirements are also proposed with worksite-specific procedures.
- In keeping with the hierarchy of controls where PPE would be a final protective measure, EPA is proposing to require that the owner or operator comply with OSHA’s General Requirements for PPE standard for application of a PPE program, including provisions and use of chemically resistant gloves, among others. EPA is also proposing to establish minimum respiratory protection requirements. EPA does not anticipate that respirators beyond an Assigned Protection Factor (APF) 50 will be widely or regularly used to address unreasonable risk, particularly when other controls are put in place.
- The proposal also outlines various scenarios for workplace exposure and the corresponding respiratory and dermal protective measures. The proposal explains that the use of respirators with an APF of 25 would control CTC air concentration levels for import, repackaging of CTC for laboratory use, recycling, industrial and commercial use of CTC as an industrial processing aid in the manufacture of agricultural products; and disposal.
- EPA is requesting comments on information to support the consideration of other APFs that are more protective as well as on engineering controls that are already in place.
Monitoring and recordkeeping requirements
- The WCPP also includes monitoring and recordkeeping requirements to verify that the established inhalation thresholds are not exceeded, and may include other components, such as dermal protection, to ensure that the chemical substance no longer presents unreasonable risk.
- EPA is proposing to require that owners or operators perform an initial exposure monitoring to determine the extent of potentially exposed persons to CTC within six months of the publication date of the final rule, or within 30 days of introduction of CTC in the workplace.
- Owners or operators would then conduct periodic monitoring for those exposure groups that exceed airborne concentration levels at least once every five years if above 0.02 ppm 8-hr TWA, and every three months if above 0.03 ppm/8-hour TWA. If the exposure is above 0.02 ppm and below 0.03 ppm/8-hour TWA, periodic monitoring must be repeated within six months of the most recent exposure monitoring. Additional requirements are listed in Table 1.
- The owner or operator would be required, within 15 working days after receipt of the results of any exposure monitoring, to re-monitor and to notify each person whose exposure is represented by that monitoring in writing, and must include the exposure monitoring results, identification and explanation of the ECEL and ECEL action level, among other information.
- EPA is proposing recordkeeping for CTC in keeping with OSHA requirements. In addition, EPA is proposing to require documentation whenever monitoring for the WCPP is required under TSCA section 6(a). Each owner or operator of a workplace subject to WCPP would have to retain compliance records for five years.
- The owner or operator would be required, within 15 working days after receipt of the results of any exposure monitoring, to notify each person whose exposure is represented by that monitoring in writing, and must include the exposure monitoring results, identification and explanation of the ECEL and ECEL action level, among other information.
- The WCPP requirements would take effect 60 days after publication of the final rule. Entities would then be required to conduct initial monitoring and the implementation of any needed exposure controls based on initial monitoring and development of an exposure control plan within one year of publication of the final rule.
- EPA proposes to require that owners and operators document their exposure control strategy and implementation in an exposure control plan or through adding EPA-required information to any existing documentation of the facility’s safety and health program developed as part of meeting Occupational Health and Safety Administration (OSHA) requirements or other safety and health standards
Downstream notification
- EPA is proposing the downstream notification for conditions of use that are not prohibited by this proposed regulation. Manufacturers (including importers), processors, and distributors of CTC would be required to provide downstream notification of certain prohibitions through safety data sheets (SDSs) by adding to sections 1(c) and 15 of the SDS this statement. The statement provides the purposes for which CTC may be used. These uses correspond to the permitted uses proposed in this regulatory action. To provide adequate time to update the SDS and ensure that all products in the supply chain include the revised SDS, EPA is proposing a six-month period for manufacturers processors and distributers to implement the proposed SDS changes following publication of the final rule.
WCPP Timelines
- The owner or operator must ensure that no person is exposed to an airborne concentration of carbon tetrachloride in excess of 0.03 ppm as an eight-hour TWA, beginning nine months after the publication of the final rule in the federal register, or beginning four months after the introduction of carbon tetrachloride into the workplace (if CTC use commences after six months after date of publication of the final rule in the federal register).
- Initial exposure monitoring must be completed for workplace manufacturing, processing, or using CTC as of the publication of the final rule in the federal register, 180 days after publication of the final rule. The proposal provides periodic monitoring requirements Table 1 to section 751.707(b)(3)(iii).
- DDCC timelines are also proposed from six months after the final rule has been published in the federal register.
- Workplace information and training timelines are proposed for those whose work involves potential exposure to CTC.
Next steps
- The proposed rulemaking to regulate uses of CTC is following a common theme from the EPA to ban certain uses of a substance and then propose a WCPP to protect workers from its use. This is the framework EPA used for perchloroethylene (see this AgencyIQ article for our analysis).
- EPA has incorporated OSHA requirements throughout the WCPP and has also proposed the use of PPE for the WCPP which is in contrast to the December 2022 Final Risk Determination for CTC which does not assume that workers will have the opportunity to use PPE.
- EPA is requesting comments on virtually every aspect of the proposal with specific detail to the WCPP. The 51 issues EPA is requesting comments for can be reviewed here.
- Comments may be submitted once Docket No. EPA HQ -OPPT-2020-0592 is active.
Featuring previous research by Patricia Iscaro.
To contact the author of this analysis, please email Patricia Iscaro.
To contact the editor of this analysis, please email Alec Gaffney.