First Risk Evaluation of PFHxA Published in Regulatory Toxicology and Pharmacology
February 8, 2019

Integral toxicologists are contributing to the state of the science in emerging contaminants with their evaluation of the current toxicology and human exposure data for perfluorohexanoic acid (PFHxA). This two-part publication is the first comprehensive, peer-reviewed summary of PFHxA toxicity and assessment of human health risks to date. PFHxA is a short-chain, six-carbon perfluoroalkyl acid and is a primary impurity, degradant, and metabolite associated with the short-chain fluorotelomer-based chemistry used globally today. The information presented in these papers will help inform site-specific risk assessments and global product stewardship and public health decisions involving PFHxA and other short-chain fluorotelomer-based chemistry.

Toxicity Value and Screening Levels Developed

A human health-based toxicity value, analogous to an EPA oral reference dose (RfD), was developed for PFHxA. In accordance with EPA policy and guidance, this peer-reviewed RfD can be used to assess potential human health risk at contaminated sites. In the companion paper, the PFHxA RfD is then used to derive screening levels for both residential groundwater and drinking water using standard EPA equations. Based on current data on environmental occurrence and potential human exposures to PFHxA, there is a high margin of safety for the general U.S. population, which means that human health risks from exposure to PFHxA are expected to be very low.

The two papers are available via open access online and will be published in the April 2019 issue (Volume 103) of Regulatory Toxicology and Pharmacology.

Publication Links

Luz, A.L., J.K. Anderson, P. Goodrum, and J. Durda. In press. Perfluorohexanoic acid toxicity, part I: Development of a chronic human health toxicity value for use in risk assessment. Regul. Toxicol. Pharmacol. doi: 10.1016/j.yrtph.2019.01.019

Anderson, J.K., A.L. Luz, P. Goodrum, and J. Durda. In press. Perfluorohexanoic acid toxicity, part II: Application of human health toxicity value for risk characterization. Regul. Toxicol. Pharmacol. doi: 10.1016/j.yrtph.2019.01.020

Contact Our Toxicologists

For more information, contact Janet Anderson at or Tony Luz at