EPA Finds Limited to No "Unreasonable" Risk for 1,4-Dioxane and HBCD

Published July 3, 2019

New draft risk evaluations published by EPA on Monday identify limited to no “unreasonable” risk associated with the solvent 1,4-dioxane and a group of cyclic aliphatic bromide flame retardants, or HBCD. EPA’s draft risk evaluation for HBCD concludes that it presents no unreasonable risks to the general population, workers, and the environment. The draft risk evaluation for 1,4-dioxane identifies unreasonable risks to workers only in certain circumstances. The agency says it found no unreasonable risks to occupational non-users, or workers who work in the general area of a chemical but do not come in direct contact with it. EPA further states that 1,4-dioxane presents no unreasonable risks to the environment and claims that environmental statutes it administers “adequately assess and effectively manage risks from 1,4-dioxane” for the general population.

EPA evaluated eight conditions of use associated with HBCD, including the processing of flame retardants used in custom compounding of resin; processing of flame retardants used in plastics product manufacturing; and recycling of foam and resin panels. The agency also evaluated the use of HBCD in building and construction materials, automobile replacement parts, and recycled plastics. EPA identified 14 conditions of use for its risk evaluation of 1,4-dioxane. The chemical’s use in adhesives and sealants, laboratory chemicals, spray polyurethane foam, and printing and printing compositions were among the conditions of use evaluated by the agency.

EPA is accepting comments on its draft risk evaluations until Aug. 30, 2019. The Science Advisory Committee on Chemicals—a federal advisory committee charged with providing scientific advice, information, and recommendations to EPA on chemicals regulated under Toxic Substances Control Act legislation—will also review the draft risk evaluations during a meeting that will be held July 29–Aug. 2, 2019, in Arlington, Va.

The two new draft risk evaluations are the second and third that EPA has published under the amended TSCA legislation. As amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act, which was signed into law in June 2016, TSCA requires EPA to complete risk evaluations for 10 chemicals, including 1,4-dioxane and HBCD, by December 2019. EPA published its first draft risk evaluation for pigment violet 29 in November 2018. The other chemicals set to undergo risk evaluations are 1-bromopropane, asbestos, carbon tetrachloride, methylene chloride, N-methylpyrrolidone, tetrachloroethylene, and trichloroethylene.

More information on EPA activities related to chemical risk evaluations is available on the agency’s website.