Documents show that DuPont and 3M knew forever chemicals were toxic by 1970, four decades before the public was aware PFAS are harmful to human health.
Per-and poly-fluoroalkyl substances (PFAS), or "forever chemicals," have been widely used in products such as non-stick cookware, food packaging, and cleaning products since the 1940s. They are highly resistant to degradation and can remain in the environment and drinking water for years. For example, estimates suggest that 200 million Americans have drinking water with PFAS that exceeds safe levels.
Despite being phased out of commercial production in the United States, manufacturers in other countries still use PFAS in their products. Moreover, forever chemicals may stay in the human body for up to 10 years. To illustrate, one recent study detected four different PFAS in 96% to 100% of pregnant participants.
And these chemicals can harm human health. For example, studies have found links between forever chemicals and immune system dysfunction, cancer, reproductive harm, and altered biological processes in children.
Health officials have known about the dangers of PFAS since the late 1990s. However, a new study published on May 31 in Annals of Global Health found that DuPont and 3M — the largest manufacturers of forever chemicals — knew PFAS were toxic by 1970 and covered it up for decades.
After reviewing previously secret company documents retrieved from the UCSF Chemical Industry Documents Library, the research team found that DuPont and 3M knew forever chemicals were highly toxic, delayed disclosing the dangers of PFAS, suppressed research that showed these harms, and distorted communication to the public.
According to the paper, "internal studies were identified, ranging from 1961 to 1994, showing 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 their findings to 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.'"
For example, records show that a 1970 industry study revealed PFAS was highly toxic when inhaled and moderately toxic when injected. In addition, a 1979 study conducted in DuPont's Haskell labs found corneal opacity and ulceration in rats and death in two dogs from ingesting PFAS in low doses. Yet, the company did not release these findings.
Moreover, 1981 industry documents show a "record of two children born to exposed workers with eye and facial defects" and "confirmed fetal eye changes" related to PFAS. During that same year, DuPont removed women of childbearing age from areas where they might be exposed to these chemicals.
However, the companies did not make these findings public. Instead, DuPont and 3M denied adverse pregnancy outcomes in a 1981 joint employee communication packet. Moreover, a 1991 DuPont company press release denied PFAS caused birth defects and other adverse health effects.
In 2006, when reports and lawsuits began to surface about the dangers of Teflon, a DuPont product made with PFAS, the company urged the Environmental Protection Agency (EPA) to "quickly (like first thing tomorrow)" announce that "consumer products sold under the Teflon brand are safe. These include the non-stick cookware in your kitchen, the stain-resistant carpet in your family room, and the waterproof jackets in your closets."
DuPont also stated, "To date, there are no human health effects known to be caused by PFOA."
In 2004, the EPA took action against DuPont for toxic substance reporting violations. As a result, the company paid a $16.45 million penalty. However, the company's 2005 revenue from PFAS chemicals PFOA and C-8 was $1 billion.
In a news release, senior study author Tracey J. Woodruff, Ph.D., a professor and director of the UCSF Program on Reproductive Health and the Environment (PRHE), says, "These documents reveal clear evidence that the chemical industry knew about the dangers of PFAS and failed to let the public, regulators, and even their own employees know the risks."
"As many countries pursue legal and legislative action to curb PFAS production, we hope they are aided by the timeline of evidence presented in this paper," Woodruff adds. "This timeline reveals serious failures in the way the U.S. currently regulates harmful chemicals."
- Agency for Toxic Substances and Disease Registry. What are PFAS?
- Environmental Health Perspectives. Birth Outcomes in Relation to Prenatal Exposure to Per- and Polyfluoroalkyl Substances and Stress in the Environmental Influences on Child Health Outcomes (ECHO) Program.
- Annals of Global Health. The Devil they Knew: Chemical Documents Analysis of Industry Influence on PFAS Science.
- EurekAlert. Makers of PFAS 'forever chemicals' covered up the dangers.