PFOA Toxicology: What’s a Safe Level for the Environment?

What toxic tort and environmental attorneys need to know about this ubiquitous compound. 

Perfluorooctanoic acid (PFOA) has been described as more toxic than methyl mercury. Yet not all organizations tasked with developing safe-dose levels agree on the best approach for PFOA, resulting in recommended levels that are more than 100-times apart.

Differences in these recommended safe-dose levels result in cleanup costs that vary by billions of dollars.


Environmental contamination with PFOA has been known for some time. In the early 2000s safe doses in drinking water were considered to be in the range of 30-to-50 parts per billion.  Recent safe-dose assessments by EPA, ATSDR and several states have significantly lowered these safe doses to parts-per-trillion measurements.

PFOA, also known as C8, is used to make Teflon® and similar chemicals known as fluorotelomers. According to the American Cancer Society, PFOA is “burned off during the [manufacturing] process and is not present in significant amounts in the final products.”

However, the American Cancer Society says, “PFOA has the potential to be a health concern because it can stay in the environment and in the human body for long periods of time. Studies have found that it is present worldwide at very low levels in just about everyone’s blood. Higher blood levels have been found in community residents where local water supplies have been contaminated by PFOA. People exposed to PFOA in the workplace can have levels many times higher.

“PFOA and some similar compounds can be found at low levels in some foods, drinking water, and in household dust. Although PFOA levels in drinking water are usually low, they can be higher in certain areas, such as near chemical plants that use PFOA.

“People can also be exposed to PFOA from ski wax or from fabrics and carpeting that have been treated to be stain resistant. Non-stick cookware is not a significant source of PFOA exposure.”

The underlying toxicity data has not changed that much. What differs is our understanding of the differences between experiments on animals and humans in how PFOA is excreted from the body. Recently it has been suggested that the federal approach to this safe dose assessment has not followed its own risk assessment guidelines. If true, this lack of adherence to guidelines calls into question whether the significantly lower safe doses are appropriate. If these much lower levels are not appropriate, then clean up standards to these levels may be overly costly.

Earlier this year, the Agency for Toxic Substances and Disease Registry (ATSDR), within the Department of Health and Human Services (HHS) announced the availability of the Draft Toxicological Profile for Perfluoroalkyls for review and comment. All toxicological profiles issued as “Drafts for Public Comment” represent ATSDR’s best efforts to provide important toxicological information on priority hazardous substances. You can see the many comments received at the ATSDR website

Is PFOA really more toxic than methyl mercury?

Do we really need to spend billions of dollars in its clean up?

How can it be that these safe doses vary so widely?

Attendees of this webinar will learn the nuances of safe dose assessment from a board-certified toxicologist, including:

— A thorough background on the toxicology of PFOA.

— A practical overview of animal vs human studies.

— An understanding of the latest federal approach to estimating the safe dose of PFOA.

— A review of the underlying risk assessment guidelines.

— An explanation of how more typical approaches likely yield higher safe-dose levels and less costly cleanups.

And more!


Dr. Michael Dourson is a board-certified toxicologist serving as the Director of Science. Most recently, he was Senior Advisor in the Office of the Administrator at the U.S. Environmental Protection Agency. Prior to this position, Dr. Dourson was a Professor in the Risk Science Center at the University of Cincinnati, College of Medicine and worked at TERA and EPA. He was awarded the Arnold J. Lehman award from the Society of Toxicology, the International Achievement Award by the International Society of Regulatory Toxicology and Pharmacology, and 4 bronze medals from the EPA. He has been elected as a Fellow of the Academy of Toxicological Sciences and as a Fellow for the Society for Risk Analysis. He has co-published more than 150 papers on risk assessment methods or chemical-specific analyses, and co-authored well over 100 government risk assessment documents, many of them risk assessment guidance texts. He has made over 150 invited presentations to a variety of organizations, and has chaired over 150 sessions at scientific meetings and independent peer reviews. He has been elected to multiple officer positions in the American Board of Toxicology (including its President), the Society of Toxicology (including the President of 3 specialty sections), the Society for Risk Analysis (including its Secretary), and is currently the President of the Toxicology Education Foundation, a nonprofit organization with a vision to help the public understand the essentials of toxicology. In addition to numerous appointments on government panels, such as EPA’s Science Advisory Board, he is a current member on the editorial board of Regulatory Toxicology and Pharmacology and Human and Experimental Toxicology.