Carbon tetrachloride (CTC) is a solvent used as a raw material in commercial settings to produce chemicals such as hydrofluoroolefins for refrigerants, aerosol propellants, foam-blowing agents, chlorinated compounds, and agricultural products.
Notably, the U.S. Consumer Product Safety Commission banned the use of CTC in consumer products in 1970. Additionally, in 1996, CTC was phased out from production in the United States for most domestic uses that did not involve manufacturing other chemicals as a result of requirements under the Montreal Protocol and the Clean Air Act.
Moreover, in November 2020, the Environmental Protection Agency (“EPA”) published a risk evaluation, which included individual unreasonable risk determinations for each condition of use evaluated. Overall, the EPA determined that 13[1] of the 15 conditions of use it evaluated drove the unreasonable risk determination, and that 2[2] of the 15 conditions of use did not drive the unreasonable risk. As a result, the determinations that particular conditions of use did not present an unreasonable risk were issued by order under the Toxic Substances Control Act (TSCA) section 6(i)(1).
However, in response to Executive Order 13990 (“Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis”) and other priorities set forth by the Biden Administration, the EPA then reviewed the risk evaluation to ensure it met the requirements of TSCA, including conducting decision-making in a manner that was consistent with the best available science and weight of the scientific evidence. To that end, the EPA reconsidered two key aspects of the previous risk determinations for CTC and determined the following: (1) that the appropriate approach is to make an unreasonable risk determination for CTC as a whole chemical substance rather than making unreasonable risk determinations separately on each individual condition of use evaluated in the risk evaluation; and (2) that the risk determination explicitly state that it does not rely on assumptions regarding the use of personal protective equipment in making the unreasonable risk determination.
As a result, the EPA determined that CTC presents an unreasonable risk to human health, including liver toxicity and cancer from chronic inhalation and dermal exposures, particularly in workers and occupational non-users (works nearby but not in direct contact with CTC). Separately, the EPA also conducted a screening-level approach to assess potential risks from the air and water pathways.
After moving forward on risk management to address the unreasonable risk presented by CTC, the EPA also identified potential risks to fenceline communities (populations in close proximity to sources of CTC) for the ambient air pathway in 2022. Then, on July 17, 2023, the EPA announced a proposal to protect workers from exposure to CTC.
If finalized, this rule would require a workplace chemical protection program, with strict controls, including inhalation exposure limits and dermal protections for the manufacturing of CTC, processing, and other industrial or commercial uses. The workplace chemical protection program would also cover uses related to the phasedown of climate pollutants under the American Innovation and Manufacturing Act, the production of chlorine and caustic soda, the manufacture of agricultural products, and repackaging for use as a laboratory chemical, recycling and disposal.
Additionally, the EPA’s workplace controls would require the use of a fume hood and dermal personal protective equipment for laboratory uses and would establish downstream notification and recordkeeping requirements. Further, the proposed rule would prohibit the use of CTC that the EPA determined have already ceased and reduce exposures to fenceline communities.
Following publication of the proposed rule, the EPA will accept comments from the public and other stakeholders for 45 days. The EPA will also host a public webinar targeted to employers and workers to discuss the proposed program.
[1] EPA’s unreasonable risk determination for CTC was driven by risks associated with the following conditions of use, considered singularly or in combination with other exposures: (1) manufacturing (domestic manufacture); (2) manufacturing (import);(3) processing as a reactant in the production of hydrochlorofluorocarbon, hydrofluorocarnon, hydrofluoroolefin, and perchloroethlyene; (4) processing: incorporation into formulation, mixtures or reactions products; (5) processing: repackaging for use as a laboratory chemical; (6) processing: recycling; (7) industrial/commercial use as an industrial processing aid in the manufacture of petrochemicals-derived products and agricultural products; (8) industrial/chemical use in the manufacture of other basic chemicals; (9) industrial/chemical use in metal recovery; (10) industrial/commercial use as an additive; (11) industrial/commercial use in the specialty uses by the Department of Defense; (12) industrial/commercial use as a laboratory chemical; and (13) disposal.
[2] The following conditions of use do not drive EPA’s unreasonable risk determination for CTC: (1) processing as a reactant/intermediate in reactive ion etching; and (2) distribution in commerce.
