WHO Releases Draft Guidelines for PFOA and PFOS, Values Significantly Higher than EPA Health Advisories

On September 29, the World Health Organization (WHO) released a background document for developing WHO Guidelines for Drinking Water Quality for PFOA and PFOS. The WHO examined information from existing reviews from the Agency for Toxic Substances and Disease Registry, the European Food Safety Authority, Health Canada, and the Environmental Protection Agency (U.S. EPA), among others, as the organization considered establishing health-based guidance values (HBGV) for the two PFAS.

After reviewing the data, WHO determined that a guidance value was warranted but that “the uncertainties in identifying the key endpoint applicable to human health following exposure to PFOS and/or PFOA are too significant to derive a HBGV with confidence.” Additionally, WHO highlights the “uncertainty and lack of consensus in the critical health end point to derive a HBGV.” Therefore, WHO opted instead to propose the derivation of provisional guideline values (pGVs) for both PFOA and PFOS. WHO proposed a pGV of 0.1 µg/L, or 100 parts per trillion (ppt), for both PFOS and PFOA individually. Additionally, WHO proposed a pGV of 0.5 µg/L, or 500 ppt, for all PFAS that currently available methods can measure, 30 different PFAS according to WHO. These numbers are significantly higher than those released by the U.S. EPA in June of this year, which set interim health advisories for PFOA and PFOS at 0.004 ppt and 0.02 ppt, respectively.

The World Health Organization is taking public comment on the background document until November 11.