EPA Finalizes Risk Evaluation for Flame Retardant TCEP

On September 23, 2024, the U.S. Environmental Protection Agency (EPA) finalized its risk evaluation of the flame retardant and plasticizer tris(2-chloroethyl) phosphate (TCEP) under the Toxic Substances Control Act (TSCA), concluding that it poses an unreasonable risk to human health and the environment. This is the first completed evaluation of the 20 High-Priority Substances identified in 2019. EPA's assessment considered TCEP exposure in vulnerable populations, including workers, pregnant women, infants, children, fenceline communities, and those with fish-heavy diets, including Tribes.

Uses and Risks Associated with TCEP

TCEP (CASRN 115-96-8) is a colorless liquid commonly used as a flame retardant and plasticizer in aerospace products, paints, and coatings. While domestic production of TCEP has dropped by 99% since 2014, it is still used in some structural and automotive applications in the U.S. and as a flame retardant and plasticizer for specific aerospace applications.

TCEP can leach into the environment, contaminating water, soil, and air. EPA has identified it as posing unreasonable risks, including kidney cancer, nervous system damage, and fertility issues, particularly to workers and consumers.

Risk Evaluation Findings

EPA has identified seven of 21 uses of the chemical TCEP as posing significant risks to workers:

• Manufacturing imports
• Paint and coating manufacturing
• Polymers used in aerospace equipment and products
• Aerospace equipment and products and automotive articles and replacement parts containing TCEP 
• Paints and coatings for industrial use 
• Paints and coatings for commercial use and 
• Laboratory chemicals

EPA has identified unreasonable risks from both inhalation and skin contact when workers handle or apply liquid formulations containing TCEP, especially in spray paints and aerospace-related resins. Consumers face risks from TCEP in fabric, foam, and wood products, particularly from inhalation or ingestion of dust. Infants and children may be vulnerable if they put such products in their mouths. EPA also highlighted concerns for people who consume large amounts of fish contaminated with TCEP, especially subsistence fishers and Tribes. Additionally, TCEP poses environmental risks, particularly to fish in contaminated water, though no significant risks were found for terrestrial animals.

Next Steps

EPA is now advancing risk management efforts to address the unreasonable risks associated with TCEP. A proposed rule will be issued under TSCA Section 6 to safeguard both humans and the environment from the identified hazards.