Last week, the United States Environmental Protection Agency (EPA) issued controversial draft risk evaluations for 1,4-Dioxane and Cyclic Aliphatic Bromide Cluster (HBCD), two of 10 chemicals subject to scrutiny under the Toxic Substances Control Act (TSCA). Under the Frank Lautenberg Chemical Safety for the 21st Century Act which amended the TSCA in 2016, the EPA is required to publish information regarding “hazards, exposures, conditions of use and potentially exposed or susceptible subpopulations,” regarding the enumerated chemicals. These risk evaluations are open for public comment for 60 days as the EPA solicits input on a final risk evaluation for the substances, with the potential for further regulation.
The brominated flame retardant HBCD has been used primarily in construction materials and can be found in polystyrene foam building insulation, car cushions, automobile interior fabrics, upholstered furniture, packaging material, and electronic equipment housing. Unfortunately, it has also been found in sludge samples in the 2001 National Sewage Sludge Survey and in river sediment in industrial areas in North Carolina and Michigan. Exposure to HBCD has been linked to reproductive and developmental disorders, and has been shown to be toxic to algae, fish and other soil-dwelling organisms.
In 2013, the Stockholm Convention listed HBCD as a persistent, organic pollutant due to its bioaccumulative and toxic properties and its use began to be phased out around the world. Japan became the first country to eliminate production and import of HBCD in 2014. Perhaps in part because of the trend away from use of HBCD, the EPA’s draft risk evaluation for it notes “no unreasonable risks for the general population, including consumers and children … no unreasonable risks to workers or occupational non-users… and no unreasonable risk to the environment.”
Unlike HBCD which has not seen much litigation, 1,4-Dioxane has already been at the center of several high profile lawsuits. 1,4-Dioxane is present in trace amounts in scores of household items and building materials, from personal care products, to toys, to adhesives, and sealants. In the preamble to its risk evaluation the EPA states that 1,4-Dioxane is a “likely human carcinogen” that “does not readily biodegrade in the environment.” However, its draft risk evaluation notes “(n)o unreasonable risks to occupational non-users …” and “no unreasonable risk to the environment.” The EPA did acknowledge some danger of exposure to 1,4-Dioxane, as it found “unreasonable risks to workers in certain circumstances.”
The EPA’s risk evaluation points to other environmental protections such as the Clean Air Act, and the Safe Drinking Water Act to “adequately assess and effectively manage risks from 1,4-dioxane,” leaving environmentalist groups howling. Given that some estimates are that the substance has found its way into the drinking water of 90 million Americans in 45 states, the battle for further regulation of 1,4-Dioxane will likely play out far beyond the 60-day public comment period.