EPA releases updated PFBS toxicity assessments
Continuing to build its library of information on per- and polyfluoroalkyl substances (PFAS), EPA issued two final assessments on the toxicity of perfluorobutane sulfonic acid (PFBS), a member of the larger group of PFAS. The toxicity assessments, for PFBS and K PFBS (the potassium salt of PFBS) provide one piece of information used in determining when there is a risk to public health.
In the assessment, chronic and subchronic oral reference doses (RfDs) for PFBS have been established. These values represent the amount of a chemical a person can ingest daily over a lifetime (chronic RfD) or less (subchronic RfD) that is unlikely to lead to adverse health effects. For PFBS the assessment established a subchronic RfD of 0.001mg/kg-day and a chronic RfD of 0.0003 mg/kg-day, greater than those of PFOA and PFOS, suggesting PFBS is less toxic to humans. Next steps for this data, include connecting these toxicity values to exposure, and other risk factors, to determine if, and when, it is appropriate to address PFBS.
PFBS is a replacement chemical for PFOS, a chemical that was voluntarily phased out in 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. Animal studies have shown health effects from PFBS, a number of organs with the thyroid appearing to be particularly sensitive to oral PFBS exposure.
















































