EPA Finds Carbon Tetrachloride Poses an Unreasonable Risk to Human Health
Released on December 27, 2022
Today, the U.S. Environmental Protection Agency (EPA) finalized a revision to the Toxic Substances Control Act (TSCA) risk determination for carbon tetrachloride, finding that carbon tetrachloride, as a whole chemical substance, presents an unreasonable risk of injury to human health when evaluated under its conditions of use. The next step in the process is to develop a risk management rulemaking to identify and require the implementation of measures to manage these risks.
Uses and Risks Associated with Carbon Tetrachloride
Carbon tetrachloride is used in commercial settings as a raw material for producing other chemicals like refrigerants, chlorinated compounds, and agricultural products. 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, so the EPA risk evaluation did not evaluate risks to consumers.
In its revised risk determination based on the 2020 risk evaluation, EPA found that carbon tetrachloride presents unreasonable risk to the health of workers and occupational non-users (workers nearby but not in direct contact with this chemical). EPA identified risks for adverse human health effects, including cancer and chronic liver toxicity from long-term inhalation and dermal exposure to the chemical and liver toxicity from short-term dermal exposure to carbon tetrachloride.
EPA used the whole chemical risk determination approach for carbon tetrachloride in part because there are benchmark exceedances for multiple conditions of use spanning across most aspects of the chemical’s life cycle, from manufacturing (including import), processing, commercial use and disposal. EPA is taking this approach for health of workers and occupational non-users, and because the health effects associated with carbon tetrachloride exposures are severe (specifically cancer and liver toxicity).
Overall, EPA determined that 13 of the 15 conditions of use EPA evaluated drive the unreasonable risk determination. Two out of 15 conditions of use do not drive the unreasonable risk: processing as a reactant/intermediate in reactive ion etching, and distribution in commerce. The revised risk determination supersedes the condition of use-specific no unreasonable risk determinations that were previously issued by order under section 6(i) of the TSCA in the 2020 carbon tetrachloride risk evaluation.
The revised risk determination for carbon tetrachloride does not reflect an assumption that workers always and appropriately wear personal protective equipment (PPE), even though some facilities might be using PPE as one means to reduce workers’ exposure. This decision should not be viewed as an indication that EPA believes there is widespread non-compliance with applicable Occupational Safety and Health Administration (OSHA) standards. In fact, EPA has received public comments from industry respondents about occupational safety practices currently in use at their facilities and will consider these comments, as well as other information on use of PPE, engineering controls, and other ways industry protects its workers, as potential ways to address unreasonable risk during the risk management process. The consideration of this information will be part of the risk management process.
EPA understands there could be occupational safety protections in place at some workplace locations. However, not assuming use of PPE in its baseline exposure scenarios reflects EPA’s recognition that certain subpopulations of workers exist that may be highly exposed because:
- They are not covered by OSHA standards (e.g., self-employed individuals and public sector workers who are not covered by a state plan);
- Their employers are out of compliance with OSHA standards;
- OSHA describes its chemical-specific permissible exposure limits (largely adopted in the 1970s) as being “outdated and inadequate for ensuring protection of worker health;” or
- The OSHA permissible exposure limit alone may be inadequate for ensuring protection of worker health, as is the case for carbon tetrachloride.
As EPA moves forward with a risk management rulemaking for carbon tetrachloride, the agency will strive for consistency with existing OSHA requirements or best industry practices when those measures would address the identified unreasonable risk. EPA will propose occupational safety measures in the risk management process that would meet TSCA’s statutory requirement to eliminate unreasonable risk of injury to health and the environment.
Next Steps for Carbon Tetrachloride
EPA is now moving forward on risk management to address the unreasonable risk presented by carbon tetrachloride. Note that in taking this action, EPA has not conducted a new scientific analysis on this chemical and the risk evaluation continues to characterize risks associated with individual conditions of use in the risk evaluation of carbon tetrachloride in order to inform risk management.
In June 2021, EPA announced a path forward for the first 10 chemicals to undergo risk evaluation under TSCA to ensure the public is protected from unreasonable risks from these chemicals in a way that is supported by science and the law. The revised risk determination for carbon tetrachloride was developed in accordance with these policy changes, as well as the Biden-Harris Administration’s Executive Orders and other directives, including those on environmental justice, scientific integrity, and regulatory review. EPA’s revisions ensure that the carbon tetrachloride risk determination better aligns with the objectives of protecting health and the environment under the amended TSCA.
Separately, EPA is conducting a screening-level approach to assess potential risks from the air and water pathways for several of the first 10 chemicals, including carbon tetrachloride. The goal of the screening approach is to evaluate the surface water, drinking water, and ambient air pathways for carbon tetrachloride that were excluded from the 2020 risk evaluation, and to determine if there are risks that were unaccounted for in that risk evaluation. EPA expects to describe its findings regarding the chemical-specific application of this screening-level approach in its proposed risk management rule for carbon tetrachloride.
Additionally, EPA expects to focus its risk management action on the conditions of use that drive the unreasonable risk. However, EPA is not limited to regulating the specific activities found to drive unreasonable risk and may select from among the range of risk management requirements included in section 6(a) of TSCA. As a general example, EPA may regulate upstream activities (e.g., processing, distribution in commerce) to address downstream activities (e.g., consumer uses) driving unreasonable risk, even if the upstream activities do not drive the unreasonable risk.