EPA Releases Final IRIS Assessment for PFBA

On December 22, EPA released the final Integrated Risk Information System (IRIS) Program Toxicological Review of Perfluorobutanoic Acid (PFBA). From EPA’s news release:

The final IRIS assessment reviews the evidence on the potential noncancer and cancer human health effects resulting from exposure to PFBA. The final assessment found that sufficient oral exposure to PFBA likely causes thyroid, liver, and developmental effects. The final assessment also includes a noncancer estimate of the amount of PFBA that one can ingest every day that is likely to be without harmful effects. These noncancer estimates can be used when conducting risk assessments to inform decision making. Regarding PFBA’s potential cancer effects, the final assessment concludes that there is “inadequate information to assess carcinogenic potential.”

EPA set an oral reference dose (RfD) for lifetime exposure of 0.001 milligrams/kilograms per day (mg/kg-day) based on liver and thyroid effects. Additionally, the Agency set an oral RfD for subchronic (less-than-lifetime) exposure of 0.006 mg/kg-day based on developmental effects. The Agency intends the assessment to be used across all EPA’s program offices and regions for a variety of decision-making needs. ASDWA submitted comments to EPA on the draft IRIS assessment for PFBA in October 2021.