Environmental Protection Agency (EPA) proposed to address the unreasonable risk of injury to human health presented by carbon tetrachloride (CTC) under its conditions of use as documented in EPA’s 2020 Risk Evaluation for Carbon Tetrachloride and 2022 Revised Unreasonable Risk Determination for Carbon Tetrachloride pursuant to the Toxic Substances Control Act (TSCA). CTC is a volatile, organic compound that is primarily used as a feedstock (i.e., processed as a reactant) in the making of products such as refrigerants, aerosol propellants, and foam-blowing agents. TSCA requires that EPA address by rule any unreasonable risk of injury to health or the environment identified in a TSCA risk evaluation and apply requirements to the extent necessary so that the chemical no longer presents unreasonable risk. EPA determined that CTC presents an unreasonable risk of injury to health due to cancer from chronic inhalation and dermal exposures and liver toxicity from chronic inhalation, chronic dermal, and acute dermal exposures in the workplace. To address the identified unreasonable risk under TSCA, EPA proposed to establish workplace safety requirements for most conditions of use, including the condition of use related to the making of low Global Warming Potential (GWP) hydrofluoroolefins (HFOs), prohibit the manufacture (including import), processing, distribution in commerce, and industrial/commercial use of CTC for conditions of use where information indicates use of CTC has already been phased out, and establish recordkeeping and downstream notification requirements. The use of CTC in low GWP HFOs is particularly important in the Agency’s efforts to support the American Innovation and Manufacturing Act of 2020 (AIM Act) and the Kigali Amendment to the Montreal Protocol on Substances that Deplete the Ozone Layer, which was ratified on October 26, 2022. The Agency’s development of this rule incorporates significant stakeholder outreach and public participation. EPA engaged in discussions with industry, non-governmental organizations, other government agencies, technical experts and users of CTC, and the general public to hear from users, academics, manufacturers, and members of the public health community about practices related to commercial uses of CTC; public health impacts of CTC; the importance of CTC in the various uses subject to this proposed rule; frequently-used substitute chemicals or alternative methods or lack thereof; engineering controls, administrative controls, and personal protective equipment currently in use or feasibly adoptable; and other risk-reduction approaches that may have already been adopted or considered for industrial and commercial uses. EPA conducted Federalism, Tribal, and Environmental Justice consultations and a Small Businesses Advocacy Review Panel. EPA's risk evaluation for CTC, describing CTC’s conditions of use, is in docket EPA-HQ-OPPT-2019-0499, with the December 2022 unreasonable risk determination and additional information in docket EPA-HQ-OPPT-2016-0733.