EPA Proposes to Designate Five Substances as High Priority
On July 25, 2024, EPA published a notice proposing to designate a new batch of existing chemicals as high priority substances under section 6 of the Toxic Substances Control Act (TSCA). TSCA section 6 requires EPA to continually designate existing chemicals as “high-priority” based on factors including hazard and exposure potential. Once a high priority designation is made, EPA is required to conduct a risk evaluation and regulate the chemical if it is found to present an unreasonable risk.
If the notice is finalized as proposed, EPA would immediately initiate risk evaluations for the following five substances:
- Vinyl Chloride (CASRN 75-01-4)
- Acetaldehyde (CASRN 75-07-0)
- Acrylonitrile (CASRN 107-13-1)
- Benzenamine (CASRN 62-53-3)
- 4,4’-methylene bis(2-chloroaniline) (MBOCA) (CASRN 101-14-4)
According to an EPA press release, vinyl chloride is a known human carcinogen linked to liver, brain, and lung cancer in exposed workers. In the release, EPA stated that vinyl chloride’s health hazards helped motivate the passage of TSCA in 1976.
The press release noted that the other four substances are probable human carcinogens and that some pose other types of hazards, such as respiratory and reproductive harms. All five substances are used to make plastic; vinyl chloride is mostly used to make polyvinyl chloride, better known as PVC.
EPA announced that it was beginning the process of prioritizing these chemicals in December 2023. In that announcement, EPA also stated that that it “expects to initiate prioritization on five chemicals every year, which will create a sustainable and effective pace for risk evaluations.”
Comments on the notice are due October 23, 2024.
