An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Assessing and Managing Chemicals under TSCA

TSCA Work Plan Chemical Problem Formulation and Initial Assessment 1,4-Dioxane

This problem formulation and initial assessment examined likely 1,4-Dioxane exposure and hazard scenarios to workers and consumers based on current production, use, and fate information. The goal of this problem formulation and initial assessment was to identify scenarios where further risk analysis may be necessary. On April 20, 2015, EPA released a problem formulation and initial assessment. The conclusions are: a) there are no risks to the general population through exposure to air emissions; b) an assessment of risk from drinking water is not needed at this time because 1,4-Dioxane is currently being monitored and EPA will determine whether or not regulatory action is needed as part of its Regulatory Determination Process; c) EPA/OPPT will further assess risks to workers and consumers exposed to 1,4-Dioxane through certain uses. EPA plans to review and evaluate the results of previous exposure assessments and health benchmarks for this chemical. As a result, EPA/OPPT will develop margins of exposure and cancer risk estimates to evaluate the potential risks from worker and consumer exposure to 1,4-Dioxane.

Return to risk evaluation for 1,4-Dioxane

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.