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Teflon Chemical Harmful at Smallest Doses

EPA's "Safe" Level is Hundreds or Thousands of Times Too Weak

August 20, 2015

Teflon Chemical Harmful at Smallest Doses: PFOA pollution is worldwide – and in people’s blood

Through Teflon’s use in hundreds of household products – carpets, clothing, food wrappers and many more – PFOA and closely related chemicals have spread to the remote corners of Earth, contaminating the blood of virtually all Americans and even passing through the umbilical cord to unborn babies in the womb.

PFOA has been linked to kidney and testicular cancers, birth defects, damage to the immune system, heart and thyroid disease, complications during pregnancy and other serious illnesses and conditions. It is hazardous at tiny doses: EPA’s health advisory level for drinking water is 0.4 parts per billion. (A part per billion, or ppb, is less than a teaspoon in an Olympic-sized swimming pool.)

Last June, the scientific journal New Solutions published a paper by Philippe Grandjean of the Harvard School of Public Health and Richard Clapp of the University of Massachusetts-Lowell, reviewing the research EPA used to set its health advisory level and comparing it to more recent studies.7

In setting its advisory level, EPA relied on studies before 2008 on the effects of PFOA and the closely related compound PFOS8, formerly used in 3M’s Scotchgard, on the weight of the liver and kidneys of rats and mice. PFOA toxicity testing has often been done using rats but female rats eliminate PFOA from their bodies much faster than people, so rats are not an ideal species for studying human developmental effects.9 EPA also considered PFOA only "suggestive" of carcinogenicity, but both an external review panel appointed by the agency and a science panel funded by the DuPont settlement10 later declared that PFOA is a “likely” cause of cancer. 

Grandjean and Clapp cited a newer study by the National Toxicology Program, EPA and the University of North Carolina. This research concluded that PFOA could disrupt hormones and suggested a possible link to breast cancer.11 That study dosed mice in the womb with very low levels of PFOA during critical development periods and could not find a level so low it did not cause harm. The scientists also drew on Grandjean’s 2013 study of more than 400 children in the Faeroe Islands of the North Atlantic. These children’s diet was heavy in PFOA-contaminated fish. The results suggested that PFOA exposure could reduce the effectiveness of childhood vaccines.12

In another sign of the growing scientific recognition that PFOA is more harmful than previously thought, the National Toxicology Program recently announced a systematic re-evaluation of the chemical’s effect on the immune system. The program’s Office of Health Assessment and Translation issued a call for the submission of ongoing or upcoming studies to be considered in the evaluation and for the nomination of scientists for an expert panel to review the findings.

Grandjean and Clapp suggested that the EPA’s approach in 2009 led to a presumed safe level “at least two orders of magnitude” higher than the newer studies indicate would protect human health with an adequate margin of safety. Grandjean and Clapp termed 0.001 ppb the “approximate” safe level for PFOA, but EWG’s calculations from their data yielded a level of 0.0003 ppb – lower than the EPA advisory level by a factor of more than 1,300.


7 Philippe Grandjean and Richard Clapp, Perfluorinated Alkyl Substances: Emerging Insights Into Health Risks. New Solutions: A Journal of Environmental and Occupational Health Policy, June 17, 2015. Available: new.sagepub.com/content/25/2/147

8 Perfluorooctanesulfonic acid.

9 Post GB, Cohn PD, Copper KR. Perfluorooctanoic acid (PFOA), an emerging drinking water contaminant: a critical review of recent literature. Environmental Research, July 2012. Available: http://www.ncbi.nlm.nih.gov/pubmed/22560884

10 The C8 Science Panel, three independent experts who for seven years studied the chemical’s effects on 70,000 residents of the mid-Ohio Valley. 

11 D.K. Tucker et al, The mammary gland is a sensitive pubertal target in CD-1 and C57BI/6 mice following perinatal perfluorooctanoic acid (PFOA) exposure. Reproductive Toxicology, July 2015. Available: www.ncbi.nlm.nih.gov/pubmed/25499722

12 Philippe Grandjean and Esben Budtz-Jørgensen, Immunotoxicty of perfluorninated alkylates: calculation of benchmark doses based on serum concentrations in children. Environmental Health, April 19, 2013. Available: www.ehjournal.net/content/12/1/35