Reaching a Consensus on PFOA Human Half-Life
Perfluorooctanoate (PFOA) is a man-made chemical that is one of the most well-known compounds in the PFAS family. The incredibly strong bonds between the carbon and fluorine chemicals in PFAS compounds make them exceptionally durable and able to withstand heat, physical force, and other chemicals.
This durability has made PFAS essential ingredients for many products that are important to daily life. However, it also means they break down slowly and can persist for many years. Although the use of PFOA was voluntarily discontinued by U.S. manufacturers two decades ago, they remain in the environment.
As Dr. Michael Dourson points out in a recent blog post, there is much disagreement in the scientific community surrounding the safety or danger of PFOA. Government agencies have not been able to determine the safe dose of PFOA because they have yet to establish its toxic effect (or “critical effect”) in the first place.
Generally, it requires more time for people to break down PFOA (or its “half-life”) than it does for animals. And since human observational studies may not identify all sources of PFOA exposure, it is hard to determine a safe dose with certainty, and half-life estimates continue to vary significantly.
Leaders in the scientific community are trying to reduce this disparity. An international effort has been formed by the Steering Committee of the Alliance for Risk Assessment (ARA) to explore data on the human half-life of PFOA to develop a consensus position, if possible.
The scientific expertise of several nominees from a range of relevant areas in the scientific field were evaluated and individuals were selected to serve on the Advisory Committee, including Center board member Dr. Tony Cox, of Cox and Associates.
The Committee formed three groups of scientists to conduct three separate, independent reviews of relevant published papers surrounding the PFOA debate. The groups will meet to discuss individual conclusions and work toward a consensus on PFOA half-life that addresses critical issues, such as the volume of distribution, half-lives in different populations, and how to account for the differences between animals and humans in experimental research and between individual people themselves.
These groups have completed their individual work and held an initial discussion. A second meeting will happen in October to form a consensus among all three groups. The group hopes to submit a final consensus conclusion to a journal for independent peer review and publication, or to be examined in an independent peer review meeting.
Their efforts coincide nicely with the Center-funded soon-to-be-released independent analysis of the research studies most frequently cited in the risk assessment, policymaking, and judicial decisions surrounding PFAS.
So much is unknown about PFAS. We hope the Steering Committee’s efforts and our research will play a role in bringing clarity on where current research stands in order to improve risk assessment and public policymaking. In doing so, we can ensure that scientific facts drive the debate surrounding the risks, safety, and use of PFAS, not the other way around.