Deadline Approaching for Comments on TSCA Prioritization of New Chemicals

Following the Environmental Protection Agency’s decision in December to begin the process of prioritizing five new chemicals for risk evaluation under the Toxic Substances Control Act (TSCA), the agency opened a public comment period to solicit any information relevant to the yearlong review process. The 90-day public comment period began on December 18 and will close on March 18. 

On December 14, The EPA announced that it was beginning the process of prioritizing five new chemicals for risk evaluation under the TSCA. The substances up for prioritization include acetaldehyde; acrylonitrile; benzenamine; 4,4’-methylene bis(2-chloroaniline) (MBOCA); and vinyl chloride. In supporting the EPA announcement, Assistant Administrator for the Office of Chemical Safety and Pollution Prevention Michal Freedhoff explained, “Moving forward to comprehensively study the safety [of] these five chemicals that have been in use for decades is key to better protecting people from toxic exposure.” The prioritization process entails a 12-month statutory period, after which the EPA will make a final determination as to whether the chemicals warrant the designation of High Priority Substances. 

Chemicals that are given this designation will consequently be moved into the risk evaluation stage of the TSCA’s regulatory process. During risk evaluation, the EPA goes through a comprehensive, rigorous protocol to determine whether the chemical “presents an unreasonable risk to health or the environment, under the conditions of use, including an unreasonable risk to a relevant potentially exposed or susceptible subpopulation.” Finally, if the agency does conclude that the chemical substance in question poses unreasonable risk, it is obligated to develop and impose restrictions that eliminate that risk, or else prohibit the substance entirely. 

Chemicals Under the TSCA Prioritization Process 

• Acetaldehyde is often used as an intermediate in the manufacturing of packaging and construction materials, plastics, and synthetic rubbers. Its broad range of applications also include disinfectants, perfumes, lacquers, and varnishes. Chemical exposure can cause irritation to the respiratory system. Based on a chemical assessment undertaken by the EPA’s Integrated Risk Information System (IRIS), acetaldehyde has been classified as a probable human carcinogen. 

• Acrylonitrile is used in the manufacturing of plastics and paints, and serves as an intermediate in the production of other chemicals. As with acetaldehyde, the health effects of acrylonitrile include irritation to the respiratory system, and IRIS has identified it as a probable human carcinogen. 

• Benzenamine serves as a precursor to the manufacture of dyes, polyurethane, and industrial chemicals. It’s also used widely in the rubber industry for the processing of car tires, gloves, and other rubber-based products. According to the EPA, benzenamine poses a health risk to fetal development and reproduction, and has also been found likely to be a human carcinogen. 

• MBOCA is found in a wide array of polyurethane products, including gears, gaskets, camera components, computers, and copy machines. In addition to being a probable human carcinogen, research carried out by the Agency for Toxic Substances and Disease Registry has determined that MBOCA has mutagenic properties, and causes damage to genetic material. (As the EPA points out, this may lead to a host of other adverse effects yet to be conclusively identified.)

• Vinyl chloride is primarily used in the manufacturing of polyvinyl chloride (PVC), a plastic resin found in everything from pipes and wire coatings to roofing and flooring materials. Vinyl chloride gained notoriety last year, when it could be seen burning in jagged columns of toxic smoke following the train derailment in East Palestine, Ohio and spurring an emergency evacuation in response to potential chemical exposure. Prolonged inhalation of the substance can result in liver damage, neurological symptoms, and other detrimental health effects. 

EPA Open Comments Period 

Federal regulations require the EPA and TSCA to provide a 90-day comment period before moving forward with the prioritization process. During this phase, the agency allows for stakeholders and other interested parties to submit information relevant to the EPA’s evaluation of the chemical substances. The agency has established a clearly defined scope for what qualifies as relevant information. This includes, among other categories, any information on the substances’ hazards and chemical exposure potential; bioaccumulation; subpopulations particularly susceptible to exposure and adverse health effects; and figures on production volume or recent changes to production volume. 

It’s worth noting, however, that the EPA did include a subtle caveat in its initial announcement of the prioritization of acetaldehyde, acrylonitrile, benzenamine, MBOCA, and vinyl chloride. While the agency acknowledged that it would review submitted information as part of its final determination, it “expects these chemicals to be designated as high-priority.” In other words, though the EPA is listening, it appears largely determined to move these chemicals further along the investigatory process by making them candidates for risk evaluation.

How to Comment on TSCA Prioritization Process 

Those interested in submitting comments on acetaldehyde, acrylonitrile, benzenamine,  MBOCA, or vinyl chloride should visit the Regulations page, under docket EPA-HQ-OPPT-2023-0601. As of February 20, the EPA had received nearly 4,000 comments on the proposed designations. One posted comment, submitted by Mike Caruso on January 2, reads, in part: 

My worry with inclusion of PVC with the latest TSCA potential prioritization would be the requirements / timing of its potential replacement as well as burden on both the municipalities and the general public (the cost to replace thousands of miles of pipelines would be astronomical). Municipalities already have to prioritize how they do (or in most cases, don't) replace aging infrastructure. This doesn't even scratch the surface on the municipalities' interaction with / education of the public to identify yet another low risk problem with the distribution system. This will drive more people to the bottled water industry at a time when we need LESS bottled water in production ... not more!