EPA Eyes Vinyl Chloride Among Other Chemicals for Risk Evaluation Under TSCA

EPA announced last month that vinyl chloride is among five chemicals it plans to prioritize for risk evaluation under the Toxic Substances Control Act (TSCA). Vinyl chloride was one of the hazardous substances on board the Norfolk Southern train that derailed in February 2023 near East Palestine, Ohio. The agency will begin risk evaluations for vinyl chloride and four other chemicals—including acetaldehyde, acrylonitrile, benzenamine, and 4,4’-Methylene bis(2-chloroaniline), or MBOCA—if it designates the chemicals as high-priority substances during the 12-month statutory process required by TSCA. EPA will immediately begin risk evaluations for chemical substances designated as high priority during this prioritization process. A designation of low priority would mean that the agency believes risk evaluation is not warranted at this time.

EPA’s decision to select these five chemicals is based in part on how they are used and whether they affect “potentially-exposed susceptible sub-populations,” including workers. In the United States, vinyl chloride is used primarily by the plastics industry to produce polyvinyl chloride, or PVC. Workers and people who live near plastic manufacturing facilities or hazardous waste sites may be exposed to vinyl chloride through inhalation. Workers may also be exposed through skin absorption. Three other chemicals identified by EPA alongside vinyl chloride for potential risk evaluation are also used to manufacture and process plastics: acrylonitrile, benzenamine, and MBOCA. According to EPA, the fifth chemical, acetaldehyde, is used in the manufacturing and processing of adhesives and petrochemicals as well as intermediates for products like packaging and construction materials.

The publication of this information in the Federal Register in mid-December launched a 90-day comment period during which interested individuals may submit information about the five chemical substances. For example, commenters may provide information regarding the substances’ hazard and exposure potential or their conditions of use. The comment period closes on March 18.

For further information, see the Federal Register notice and EPA’s news release, and its webpage on chemical substances undergoing prioritization.