EPA is releasing draft toxicity assessments for GenX chemicals and PFBS. Following closure of this 60-day public comment period, the EPA will consider the comments, revise the draft documents, as appropriate, and then publish final toxicity assessments. The comment period closes on January 22, 2019.  

Communication Materials

• Press Release: EPA seeks public input on draft toxicity assessments for PFAS chemicals (November 14, 2018)
• Fact Sheet: Draft Toxicity Assessments for GenX Chemicals and PFBS 
• Technical Fact Sheet: Draft Toxicity Assessments for GenX Chemicals and PFBS

Federal Register Notice

• Federal Register Notice: Request for Public Review and Comment: Draft Human Health Toxicity Assessments for Hexafluoropropylene Oxide Dimer Acid and its Ammonium Salt (GenX Chemicals) and for Perfluorobutane Sulfonic Acid (PFBS) and Related Compound Potassium Perfluorobutane Sulfonate

Toxicity Assessments

• Toxicity Assessment: Human Health Toxicity Values for Hexafluoropropylene Oxide (HFPO) Dimer Acid and Its Ammonium Salt (CASRN 13252-13-6 and CASRN 62037-80-3)
• Toxicity Assessment: Human Health Toxicity Values for Perfluorobutane Sulfonic Acid (CASRN 375-73-5) and Related Compound Potassium Perfluorobutane Sulfonate (CASRN 29420-49-3)

Supporting Documents

• Response to Peer Review Comments: Draft Human Health Toxicity Values for Hexafluoropropylene Oxide (HFPO) Dimer Acid and Its Ammonium Salt (CASRN 13252-13-6 and CASRN 62037- 80-3) also known as "GenX Chemicals"
• Response to Peer Review Comments:  Draft Human Health Toxicity Values for Perfluorobutane Sulfonic Acid (CASRN 375-73-5) and Related Compound Potassium Perfluorobutane Sulfonate (CASRN 29420-49-3)

Complete Set of Materials