In July, the U.S. Environmental Protection Agency (EPA) proposed to designate five chemicals as High-Priority Substances for risk evaluation under the Toxic Substances Control Act (TSCA) including vinyl chloride, primarily used in the manufacturing and processing of plastic materials such as polyvinyl chloride (PVC) pipe.
If EPA finalizes these designations as proposed, the agency would immediately move forward with the risk evaluation process. The five chemical substances EPA is proposing to designate as High-Priority Substances are:
- Vinyl Chloride (CASRN 75-01-4),
- Acetaldehyde (CASRN 75-07-0),
- Acrylonitrile (CASRN 107-13-1),
- Benzenamine (CASRN 62-53-3), and
- 4,4’-methylene bis(2-chloroaniline) (MBOCA) (CASRN 101-14-4).
All five chemicals were selected from the 2014 TSCA Work Plan, which is a list of chemicals identified by EPA for further assessment based on their hazards and potential for exposure. In proposing these five chemical substances as High-Priority Substances for risk evaluation, EPA said it had to consider the chemicals’ conditions of use and production volume or changes in conditions of use and production volume over time, impacts to potentially exposed or susceptible subpopulations including children and workers, and the chemicals’ potential hazards and exposures. EPA also considered more specific criteria such as the chemicals’ bioaccumulation and environmental persistence and whether the chemical is stored near significant sources of drinking water.
Vinyl Chloride
Vinyl chloride is used primarily in the manufacturing and processing of plastic materials such as polyvinyl chloride (PVC), plastic resins and other chemicals. Many of these materials are used for pipes and insulating materials. This chemical was also involved in the Norfolk Southern train derailment in East Palestine, Ohio. Vinyl chloride is a known human carcinogen and can cause liver, brain and lung cancer in exposed workers. Short-term exposure to vinyl chloride can also result in other health effects such as dizziness, nausea, and eye and skin irritation. Vinyl chloride exposure can also damage genetic material in cells, which can lead to numerous adverse health effects. In the 1970s, the White House Council on Environmental Quality and EPA officials raised serious concerns about the health impacts of vinyl chloride as an example when the Nixon Administration asked Congress to write a law to ensure chemicals were made and used safely, which led to passage of the “original” TSCA in 1976.
Prioritization & Process Improvements
Prioritization is the first step under EPA’s authority to regulate existing chemicals currently on the market and in use. EPA’s proposed designations are not themselves a finding of risk. If EPA finalizes these designations, the agency will initiate risk evaluations for these chemicals to determine whether they present an unreasonable risk to human health or the environment under the TSCA conditions of use (the way the chemical is made and used), which the agency is required to complete within 3-3.5 years. If at the end of the risk evaluation process EPA determines that a chemical presents an unreasonable risk to health or the environment, the agency must begin the risk management process to take action to eliminate these unreasonable risks.
EPA began the process of prioritizing these five chemicals in December 2023 and also announced that it expects to initiate prioritization on five chemicals every year, which will create a sustainable and effective pace for risk evaluations. Over the past year, EPA has continued to improve the prioritization process by investing in cutting-edge software to review more information earlier in prioritization.
EPA will accept public comments on the proposed designations for 90 days after publication via docket EPA-HQ-OPPT-2023-0601 at the Regulations.gov page. Upon publication of the Federal Register notice, supporting documents will also be available in the docket.
Learn more about the prioritization process under TSCA.
EPA said this step is consistent with a commitment from the Biden-Harris Administration to “understand and address environmental and toxic exposures to ensure that every community has access to clean air and water.” EPA added the move also “supports the Cancer Moonshot’s mission to end cancer as we know it, and bolsters the Administration’s efforts to make progress on delivering environmental justice and tackling plastic pollution.”
“The Biden-Harris Administration continues to make significant progress in protecting workers and communities from exposure to harmful chemicals as we implement the 2016 TSCA amendments that strengthened EPA’s authority on chemical safety,” said Assistant Administrator for the Office of Chemical Safety and Pollution Prevention Michal Freedhoff. “Studying the safety of these harmful chemicals – all five of which have been linked to cancer and are used to make plastic – would help lead to critical public health and environmental protections in communities across the country and would ensure that the public has access to more data on these chemicals sooner.”
Source: EPA
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