The U.S. Environmental Protection Agency (EPA) announced on April 8, 2021, that it is releasing an updated toxicity assessment for perfluorobutane sulfonic acid (PFBS), which is a member of the group of per- and polyfluoroalkyl substances (PFAS).  EPA states that this PFBS assessment is part of its commitment to restore scientific integrity to all of the Agency’s actions and increase the amount of research and information available to the public on PFAS.  According to EPA’s announcement, “EPA, federal agencies, states, tribes, and local communities can use the PFBS toxicity assessment, along with specific exposure and other relevant information, to determine if and when it is necessary to take action to address potential health risks associated with human exposures to PFBS under appropriate regulations and statutes.”  EPA notes that the updated assessment “has gone through all appropriate reviews, includes input EPA received from external peer review, upholds the tenants of scientific integrity, was authored by expert career scientists in EPA’s Office of Research and Development, and has not been compromised by political staff -- these were all issues with a version of the assessment that was posted during the previous administration.  The release of today’s PFBS assessment upholds the integrity of EPA’s science, which EPA, states, tribes, and more rely on to make decisions that protect the health of their communities.”

According to EPA’s fact sheet on the toxicity assessment, PFBS is a replacement chemical for perfluorooctanesulfonic acid (PFOS), a PFAS that was voluntarily phased out by the primary U.S. manufacturer by 2002.  PFBS has been identified in the environment and consumer products, including surface water, wastewater, drinking water, dust, carpeting and carpet cleaners, and floor wax.  The fact sheet states that the PFBS toxicity assessment is comparable to assessments developed under EPA’s Integrated Risk Information System (IRIS) and Provisional Peer-Reviewed Toxicity Value (PPRTV) Programs in that it provides hazard identification, dose-response information, and toxicity values.  EPA will continue to work with state, tribal, and local partners to provide technical assistance as they consider the final PFBS toxicity values in relevant exposure scenarios.  The fact sheet notes that at this time, EPA does not plan to issue a regulation for PFBS.