EPA publishes final revised risk determination for 1,4-dioxane

Washington — The Environmental Protection Agency says the potentially carcinogenic chemical substance 1,4-dioxane poses “unreasonable risk” to workers under certain conditions.

A final revised risk determination published on July 26 states that 1,4-dioxane – frequently used in consumer products – poses unreasonable risks to workers in:

• Domestic manufacturing
• Uses as a processing aid or laboratory chemical
• Uses as an adhesive and sealant
• Printing and printing compositions
• Disposal
• Hydraulic fracturing

EPA reopened and updated the risk evaluation for 1,4-dioxane after publishing a final risk evaluation in January 2021.

A draft supplemental risk evaluation released in July notes that the agency uncovered more risks than initially determined. EPA says the chemical substance poses an estimated cancer risk “higher than 1 in 10,000 for a range of occupational exposure scenarios associated with 1,4-dioxane produced as a byproduct.”

Comments are due Sept. 8.