The Environmental Protection Agency (EPA) has announced the availability of the draft scope for the risk evaluation of vinyl chloride under the Toxic Substances Control Act (TSCA). This evaluation aims to determine whether vinyl chloride poses an unreasonable risk to health or the environment. The draft scope, released on 16 January 2025, outlines the conditions of use, hazards, exposures, and potentially exposed or susceptible subpopulations that the EPA plans to consider.
Understanding Vinyl Chloride and Its Uses
Vinyl chloride, also known as chloroethylene, is a chlorinated ethene primarily used as a monomer in the production of polyvinyl chloride (PVC). PVC is widely utilised in consumer, commercial, and industrial applications, including construction materials, packaging, and automotive components. The chemical's production volume in the United States ranges between 10 and 20 billion pounds annually.
Health and Environmental Risks
The EPA's draft scope highlights the potential health and environmental risks associated with vinyl chloride. The agency plans to evaluate both cancer and non-cancer hazards, considering inhalation as a primary exposure route. Vinyl chloride is a known human carcinogen, with evidence linking it to liver cancer and other health issues. The draft scope also addresses the chemical's environmental fate, noting its high volatility and tendency to partition into the air, which could lead to significant inhalation exposure for both humans and ecological species.
Regulatory Framework and Evaluation Process
Under TSCA, the EPA is required to conduct risk evaluations for high-priority substances like vinyl chloride. The draft scope is the first step in this process, providing a framework for the evaluation. The EPA will consider public comments on the draft scope before finalising it and proceeding with the risk evaluation. The agency aims to complete the evaluation within a three to three-and-a-half-year statutory timeframe.
Public Participation and Next Steps
The EPA encourages stakeholders, including industry representatives, non-governmental organisations, and the general public, to provide feedback on the draft scope. Comments can be submitted online until 3 March 2025. The agency will review the feedback and incorporate relevant information into the final scope. Once the scope is finalised, the EPA will conduct a comprehensive risk evaluation, considering all reasonably available information and using systematic review methods to ensure a thorough assessment.
