An official website of the United States government.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Assessing and Managing Chemicals under TSCA

Chemical Substances Undergoing Prioritization

As required under section 6(b) of the Toxic Substances Control Act (TSCA), EPA must conduct a prioritization process to determine if chemical substances are a high or low priority for risk evaluation.

On March 20, 2019, EPA initiated the prioritization process by issuing a list of 40 chemical substances and began the effort to designate 20 substances as “high priority” for subsequent risk evaluation and to designate 20 substances as “low priority,” meaning that risk evaluation is not warranted at this time. Publication in the Federal Register activated a statutory requirement for EPA to complete the prioritization process in the next nine to twelve months, allowing EPA to designate 20 chemical substances as high priority and 20 chemical substances as low priority by December 2019.