A recent study by UC San Francisco (UCSF) researchers has found that the chemical industry suppressed information related to the health harms caused by exposure to PFAS (per- and polyfluoroalkyl substances) in a manner similar to how the tobacco industry concealed the harmful effects of smoking. Published in Annals of Global Health on May 31, 2023, the report analyses previously confidential documents from DuPont and 3M, the largest PFAS manufacturers. The paper examines the tactics employed by the industry to delay public awareness of PFAS toxicity, thereby delaying regulations governing their use. PFAS are widely used chemicals that are highly resistant to breaking down, giving them the name “forever chemicals.” They are now ubiquitous in people and the environment.
The Study’s Findings
The paper, titled “The Devil They Knew: Chemical Documents Analysis of Industry Influence on PFAS Science,” reveals that for the first fifty years of PFAS use, little was publicly known about their toxicity. The industry had multiple studies showing adverse health effects at least 21 years before they were reported in public findings. The paper documents a timeline of what the industry knew versus public knowledge and analyses the strategies used by the chemical industry to suppress information or protect their harmful products.
The study found that DuPont had evidence of PFAS toxicity from internal animal and occupational studies that they did not publish in the scientific literature and failed to report to the Environmental Protection Agency (EPA) as required under TSCA. These documents were all marked as ‘confidential,’ and in some cases, industry executives were explicit that they ‘wanted this memo destroyed.’
The paper provides examples of the industry’s knowledge of PFAS toxicity versus public knowledge. For instance, in 1961, Teflon’s Chief of Toxicology discovered that Teflon materials had “the ability to increase the size of the liver of rats at low doses” and advised that the chemicals “be handled ‘with extreme care’ and that ‘contact with the skin should be strictly avoided.’” According to a 1970 internal memo, DuPont-funded Haskell Laboratory found that C8 (one of thousands of PFAS) was “highly toxic when inhaled and moderately toxic when ingested.” In a 1979 private report for DuPont, Haskell labs found that dogs exposed to a single dose of PFOA “died two days after ingestion.” In 1980, DuPont and 3M learned that two of eight pregnant employees who had worked in C8 manufacturing gave birth to children with birth defects. The company did not publish the discovery or tell employees about it, and the following year an internal memo stated, “We know of no evidence of birth defects caused by C-8 at DuPont.”
Despite these and more examples, DuPont reassured its employees in 1980 that C8 “has a lower toxicity, like table salt.” Referring to reports of PFAS groundwater contamination near one of DuPont’s manufacturing plants, a 1991 press release claimed, “C-8 has no known toxic or ill health effects in humans at concentration levels detected.” As media attention to PFAS contamination increased following lawsuits in 1998 and 2002, DuPont emailed the EPA asking, “We need EPA to quickly (like first thing tomorrow) say the following: That consumer products sold under the Teflon brand are safe and to date there are no human health effects known to be caused by PFOA.”
In 2004, the EPA fined DuPont for not disclosing their findings on PFOA. The $16.45 million settlement was the largest civil penalty obtained under U.S. environmental statutes at the time. However, it was only a small fraction of DuPont’s $1 billion annual revenues from PFOA and C8 in 2005.
The authors of the paper argue that the chemical industry’s suppression of information about the health harms of PFAS has serious implications for the way the U.S. currently regulates harmful chemicals. The study provides a timeline of evidence that can aid countries pursuing legal and legislative action to curb PFAS production. The study recommends a precautionary principle of chemical regulation instead of a reactionary approach.
The UCSF study reveals that the chemical industry suppressed information on the health harms of PFAS in a similar manner to the tobacco industry’s concealment of smoking’s harmful effects. The study analyses previously confidential documents from DuPont and 3M, the largest PFAS manufacturers, and documents the industry’s knowledge of PFAS toxicity versus public knowledge. The paper provides examples of DuPont’s suppression of information related to PFAS toxicity, including the fact that the company failed to report their findings to the EPA as required under TSCA. The authors argue that the industry’s suppression of information about the health harms of PFAS has serious implications for the way the U.S. currently regulates harmful chemicals.
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