Reviewers Belatedly Question EPA's 'Likely' Cancer Listing For Dioxane

Experts reviewing the Environmental Protection Agency's draft assessment setting first-time inhalation risks for 1,4-dioxane are split on whether the agency had enough evidence to back up its already final decision to set the chemical's listing to “likely human carcinogen.” OSHA has a permissible exposure limit (PEL) for dioxane of 100 ppm, 8-hour TWA, with a skin notation, and the chemical has come up in recent stakeholder discussions about updating OSHA's PELs. NIOSH has established a recommended exposure limit for dioxane of 1 ppm as a 30-minute ceiling, and also considers dioxane a potenti