EPA announces the final supplement to the risk evaluation and revised unreasonable risk determination for 1,4-dioxane under TSCA. This is not a NEPA document but a TSCA action notice. EPA determined that 1,4-dioxane presents unreasonable risk to human health based on cancer and non-cancer risks to workers via inhalation and dermal exposure, and cancer risks to the general population including fenceline communities from drinking water contaminated by industrial discharges and down-the-drain disposals. EPA must now initiate risk management actions under TSCA section 6(a) and will coordinate with the Office of Water on Safe Drinking Water Act authorities.12