EPA releases initial analysis for TSCA Work Plan assessment of 1,4-dioxane.

EPA today announced the release of its Problem Formulation and Initial Assessment for 1,4-dioxane, a widely used industrial solvent and ingredient in a variety of products, including cleaners, cosmetics, dyes and paint strippers, which the EPA has classified as “likely to be carcinogenic to humans.” The Problem Formulation and Initial Analysis, part of the agency’s Toxic Substances Control Act (TSCA) Work Plan risk assessment program, concludes that there is no concern for inhalation exposure of ambient air emissions by the general population. However, EPA plans to further assess potential risks to both workers exposed via inhalation during product formulation and use as a cleaning agent and to workers and consumers that use products containing 1,4-dioxane as a contaminant, such as paints, varnishes, adhesives, cleaners and detergents. EPA intends to use existing data and methods to conduct additional risk analysis, review previous health and exposure studies, and “develop margins of exposure and cancer risk estimates.” The Problem Formulation and Initial Assessment also concluded that assessing risk from drinking water exposure is not currently necessary due to ongoing monitoring by EPA’s Office of Water, so “decisions as to whether or not to regulate the contaminant in drinking water will be considered as part of the EPA’s Regulatory Determination process.” In addition, the agency announced that further environmental risk analysis would not be pursued because of the low hazard profile for 1,4-dioxane to aquatic organisms and the lack of hazard data for sediment and soil organisms.