Final Risk Evaluation for Carbon Tetrachloride

In December 2022, EPA released a final revised risk determination for carbon tetrachloride (CTC) as a whole chemical substance. This final revision supersedes the previous condition of use-specific risk determinations in the 2020 CTC risk evaluation (and withdraws the associated order under TSCA section 6(i)(1)). These chemical-specific changes are in accordance with the path forward for the first 10 risk evaluations under TSCA laid out by EPA in June 2021. 

The final revised risk determination does not assume that all workers exposed to CTC are always provided or appropriately wear personal protective equipment (PPE). The consideration of this information will be part of the risk management process. 

EPA determined that 13 out of the 15 conditions of use evaluated drive the determination that CTC presents an unreasonable risk of injury to human health under its conditions of use. 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.

Read the Federal Register notice.

Read the final revised carbon tetrachloride risk determination.

Read the Response to Public Comments to the draft revised Unreasonable Risk Determination for carbon tetrachloride.

On this page:

Risk evaluation findings
Next steps and public participation
2020 risk evaluation and supporting documents

On other pages:

Risk Evaluation Findings

In December 2022, EPA released a final revised risk determination for CTC. The final revised risk determination finds that CTC presents an unreasonable risk of injury to health under its conditions of use. 

In the November 2020 risk evaluation, EPA reviewed the exposures and hazards of CTC and made risk findings on this chemical. This risk evaluation included input from the public and peer reviewers as required by TSCA and associated regulations. EPA considered the hazards and exposures, magnitude of risk, exposed populations, severity of the hazards, uncertainties, and other factors as part of its unreasonable risk determinations. 

EPA determined that CTC, as a whole chemical substance, presents unreasonable risk to human health.

EPA assessed the impact of CTC on workers and occupational non-users. The primary health risks identified in the risk evaluation are cancer and chronic liver toxicity from long-term inhalation and dermal exposures and liver toxicity from short-term dermal exposure to the chemical. After reviewing these data, EPA determined that risk to workers and occupational non-users (workers nearby but not in direct contact with this chemical) drive the whole chemical determination of unreasonable risk. Risk from 13 out of 15 conditions of use evaluated drive the whole chemical determination of unreasonable risk of injury to health. Two out of the 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 for CTC does not reflect an assumption that workers always and appropriately wear personal protective equipment, even though some facilities might be using PPE as one means to reduce worker exposure, or that there is widespread non-compliance with applicable federal standards. 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 Occupational Safety and Health Administration (OSHA) standards, because their employers are out of compliance with OSHA standards, because OSHA’s chemical-specific Permissible Exposure Limits (PEL), largely adopted in the 1970s, are described by OSHA as being “outdated and inadequate for ensuring protection of worker health,” or because the OSHA PEL alone may be inadequate for ensuring protection of worker health, as is the case for carbon tetrachloride. The consideration of information on use of PPE, engineering controls, and other ways industry protects its workers, as potential ways to address unreasonable risk will be part of the risk management rule development process.

Next Steps and Public Participation

In June 2023, EPA proposed a risk management rule to address unreasonable risks posed by carbon tetrachloride (CTC) to human health. Learn more and submit a comment.

EPA will also host a webinar in the coming weeks about the proposed risk management rule. Registration information will be forthcoming.

Stay up to date on additional opportunities for public participation. Just like the risk evaluation process, there will be opportunities for public comment as EPA works to propose and finalize risk management actions for CTC. You can stay informed by signing up for our email alerts or checking the public docket at EPA-HQ-OPPT-2016-0733 at www.regulations.gov. 

2020 Risk Evaluation and Supporting Documents

Below are the final revised risk determination, 2020 risk evaluation for CTC, non-technical summary, response to comments, and other supporting documents.

The discussion of the issues in the final revision to the risk determination supersedes any conflicting statements in the prior CTC risk evaluation and the response to comments document.

Read the Federal Register notice.

Final Risk Evaluation for Carbon Tetrachloride

Risk Evaluation Findings

Next Steps and Public Participation

2020 Risk Evaluation and Supporting Documents

Assessing and Managing Chemicals under TSCA