Manufacturers of “Forever Chemicals” Have Been Hiding Their Dangers for Decades

A new study finds that manufacturers of cancer-causing “forever chemicals” knew about the dangers they posed 40 years before the public. Taking a cue from Big Tobacco, companies like 3M and DuPont successfully suppressed research and regulation for decades.

3M headquarters in Maplewood, Minnesota. (Michael Siluk / Education Images / Universal Images Group via Getty Images)

The manufacturers of “forever chemicals” used in products like nonstick pans and waterproof clothing knew about the dangers their materials posed more than forty years before the general public, according to previously secret industry documents. By following the same playbook as Big Tobacco, including suppression of their own research, the companies successfully stymied regulation for decades while the cancer-causing chemicals became ubiquitous in the water, air, and soil.

Major manufacturers are already spending billions to settle lawsuits and millions fighting federal regulations, including landmark environmental rules proposed this spring. The revealing industry documents, analyzed in a new study from researchers at the University of California San Francisco (UCSF), could bolster efforts to hold the companies accountable for widespread contamination from chemicals that take hundreds of years to break down. The manufacturer 3M is reportedly preparing to pay $10 billion to settle claims that it polluted thousands of public water systems, but the cost of cleaning up the chemicals in drinking water nationwide will likely top $400 billion.

Introduced into a variety of consumer goods beginning in the 1950s, per- and polyfluoroalkyl compounds, or PFAS, are linked to decreased fertility, developmental delays, and several types of cancer.

While the human health risks became widely known during the last decade, manufacturers have known since at least 1970 that the compounds were “highly toxic when inhaled and moderately toxic when ingested,” according to the industry documents obtained through litigation and reviewed by public health researchers at UCSF.

State officials and consumer groups are urging the Environmental Protection Agency (EPA) to finalize the first-ever enforceable standards for PFAS in drinking water, after decades of deferring to industry groups. Two major manufacturers, 3M and DuPont, reported spending a combined total of more than $3.8 million lobbying on chemical issues including PFAS regulation last year.

Meanwhile, dozens of states are currently considering legislation banning their use in everyday products. Exposure to PFAS is so widespread that the Centers for Disease Control and Prevention (CDC) estimates the chemicals are present in the blood of 97 percent of Americans.

“The Devil They Knew”

A growing wave of litigation, including lawsuits brought by the attorneys general of New Mexico and Washington last week, centers on allegations that DuPont, 3M, and other manufacturers “knew or should have known” about the potential harms caused by their products.

The newly available documents reviewed by UCSF researchers establish that not only did manufacturers know about these risks, they took steps to cover them up.

During the 1970s, a DuPont-funded laboratory carried out a series of studies to test the effects of exposure to the chemical coating Teflon. The laboratory had already established that Teflon dispersions could be highly toxic when inhaled, according to a 1970 DuPont memo. Subsequent tests found that rats exposed at low levels developed enlarged livers; dogs injected with higher ones died within two days.

But instead of reporting these findings to federal regulators, as required by law, the company adopted a communications strategy equating the toxicity of the chemicals to common table salt.

By 1980, employee surveys by DuPont and 3M found that pregnant workers exposed to the chemicals were giving birth to babies with abnormalities in their eyes and tear ducts. While assuring workers that they had discovered “no evidence of birth defects,” the company quietly removed female employees from high-exposure areas.

In the subsequent decades, as evidence of adverse effects mounted, the companies pressured regulators to help them mitigate the fallout. After a panel of outside experts submitted recommendations to the EPA in 2006 that called PFAS a “likely human carcinogen” and urged adoption of stricter regulations, DuPont’s vice president wrote to company executives with a plan to control the narrative.

“The only voice that can cut through the negative stories is the voice of the EPA,” reads a February 2006 email. The email went on to list proposed talking points for the agency, including that consumer products using Teflon were safe for continued use.

The EPA appears to have obliged, telling consumers in March 2006 that they did not need to stop using their nonstick products.

This March, the EPA proposed groundbreaking regulations setting limits on PFAS compounds in drinking water, though those limits are still higher than what many public health advocates say is safe to drink.

3M and the Chemours Company, which spun off from DuPont in 2015, both submitted comments opposing the rules, which are expected to be finalized next year.

The UCSF study’s authors compare the chemical companies’ tactics to Big Tobacco’s decades-long campaign to bury unfavorable research and sew misinformation in public health discourse.

“Like Big Tobacco, the major chemical manufacturers have a vested financial interest in suppressing scientific evidence of the harms of their products while maintaining the public perception that their products are safe,” according to the study. “The U.S.’s failure to shift the burden of proof to the industry with respect to chemical policy means that we may always be chasing the devil they knew, rather than defending public health from the outset.”