Risk Evaluation for Carbon Tetrachloride
In June 2023, EPA proposed a risk management rule to address unreasonable risks posed by carbon tetrachloride (CTC) to human health. Learn more about risk management for carbon tetrachloride.
In December 2022, EPA released a final revised risk determination for CTC, which amends the November 2020 risk evaluation for CTC under the amended Toxic Substances Control Act (TSCA). The final revisions to the risk determination were made 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 is based on CTC as a whole chemical substance (rather than on individual conditions of use) and does not assume that all workers exposed to CTC are always provided or appropriately wear personal protective equipment. The consideration of information on use of personal protective equipment, engineering controls, and other ways industry protects its workers as potential ways to address unreasonable risks will be part of the risk management process.
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CTC is a solvent used in commercial settings as a raw material for producing other chemicals like refrigerants, chlorinated compounds, and agricultural products in accordance with the Clean Air Act and Montreal Protocol. The Consumer Product Safety Commission (CPSC) banned the use of CTC in consumer products (excluding unavoidable residues not exceeding 10 ppm atmospheric concentration) in 1970. Therefore, CTC is not currently used as a direct reactant or additive in the formulation of consumer products.
In December 2022, EPA released a final revised risk determination. The final revised risk determination finds that CTC presents an unreasonable risk of injury to human health under its conditions of use.
In the final revised risk determination, EPA found unreasonable risk to workers and occupational non-users. Overall, 13 of the 15 conditions of use EPA evaluated drive the CTC whole chemical unreasonable risk determination due to risks identified for human health. Removing the assumption that workers always and appropriately wear PPE in making the whole chemical risk determination for CTCdoes not alter the conditions of use that drive the unreasonable risk determination for carbon tetrachloride. However, without the assumed use of PPE, inhalation exposures to workers now also drive the unreasonable risk and dermal exposures also drive the unreasonable risk due to non-cancer effects (specifically liver toxicity). In addition, the November 2020 Risk Evaluation contains a typographical error in the acute dermal point of departure (POD). This error was corrected in an errata memorandum dated July 2022 and the changes to the risk estimates are reflected in the revision to the risk determination. The corrections do not alter the conditions of use that drive the unreasonable risk determination for CTC.
In November 2020, EPA released the risk evaluation for CTC.
In January 2020, EPA released the draft risk evaluation for CTC for public comment and peer review.
- Read the draft risk evaluation for carbon tetrachloride.
- Learn more about the peer review for carbon tetrachloride.
In June 2017, EPA released the scope document for CTC which included the hazards, exposures, conditions of use, and the potentially exposed or susceptible subpopulations EPA expected to consider in its risk evaluation. In June 2018, EPA released the problem formulation for CTC which refined the scope of the risk evaluation by clarifying the chemical conditions of use that EPA expected to evaluate and describing how EPA expected to conduct the evaluation.
- Read the problem formulation for carbon tetrachloride.
- Read the scope document and supplemental files for carbon tetrachloride.
After releasing the scope documents for each of the first 10 chemicals undergoing risk evaluation under TSCA, the dockets for each of these first 10 chemicals were open for public comments. Read EPA’s Responses to Public Comments Received on the Scope Documents for the First Ten Chemicals for Risk Evaluation under TSCA. This document addresses cross-cutting public comments received in response to the scope document.