Trump EPA relied on industry science to weaken formaldehyde cancer rules, documents show

A new trove of chemical producer and US Environmental Protection Agency documents reveal an elaborate industry operation that killed strong regulations around formaldehyde, a highly toxic carcinogen widely used in everyday goods from cosmetics to furniture to craft supplies.The Biden EPA in late 2024 determined any exposure to formaldehyde increased the risk of cancer and other health problems. The Trump EPA in late 2025 moved to undo those findings and replace them with less protective figures.The newly released documents show the industry and the Trump EPA’s scientific justification for weakening the protections largely relied on, or aligned with, a small number of studies led by a chemical industry scientist, Rory Conolly, who argued that some exposure to formaldehyde is safe. The Conolly studies were funded by chemical trade groups. Between 2008-2024, the EPA had concluded the research was out of date or unreliable, documents show.Once the Trump administration took over the EPA, it changed formaldehyde risk levels to align with the level Conolly found was safe. It relied in part on his assessments, limited data from other researchers, or studies the EPA previously found to be out of date. Advocates say the documents show the Trump EPA often “cherry picked” data.The documents, obtained via a Freedom of Information Act request by the Environmental Defense Fund (EDF), a non-profit, also show an unusual three-day meeting in 2023 among the EPA and top formaldehyde producers, users and trade groups. Among the presenters was Conolly.Much of industry and the Trump EPA claims and justification are “based on what Conolly did”, said Maria Doa, a former EPA scientist now with EDF. The documents shine a light on the ferocity with which the powerful chemical lobby attacks regulations to protect its profits.“The bottom line is money – and that they want limited regulations on the chemicals they are making,” Doa told the Guardian.The EPA said in a statement that it changed the levels because the “Biden Administration used flawed analyses in its risk assessment of formaldehyde”. The new assessment takes into account a wider range of views, and “strengthens protections by relying on gold standard science”, a spokesperson said.Chemical makers annually produce up to 5bn pounds of formaldehyde, a pungent colorless gas at room temperature. Companies add it to consumer products because it’s an effective preservative, binder, anti-fungal or it is used in glue.The industry has, for decades, waged an intense war against formaldehyde regulations. But the latest salvo is bigger than just formaldehyde, said Erik Olson, a senior adviser with the Natural Resources Defense Council Action Fund who has lobbied on toxic chemical issues.The EPA has established a pathway that could be used to re-evaluate and weaken regulations around every carcinogen, Olson said, and that could lead to a broad increase in the public’s exposure to toxic chemicals.“We hear about making America healthy again, but here we have an example of the EPA undermining decades of understanding around a cancer-causing chemical for which there is no safe level of exposure,” Olson said.“Watch out. There are a lot of other carcinogens that industry wants to pick off.”‘The whole thing is crazy’The EPA during the Biden years conducted a multiyear, systematic review of the latest formaldehyde science from its own researchers, independent scientists and some industry-affiliated labs. This was its justification for concluding that the safe level of exposure to formaldehyde via inhalation is zero.The Trump EPA replaced that finding with the claim that cancer only becomes a risk at a higher “threshold”. The Trump EPA and Conolly found that the threshold is .3 parts per million (ppm), the same level at which exposure to the formaldehyde causes sensory irritation. They claim protecting against irritation will also protect against cancer.That conclusion contradicts a much broader body of research that found cancer risk at a lower level than the irritation threshold.“The whole thing is crazy,” Doa said.Conolly’s studies from over the last 20 years are repeatedly cited in industry documents obtained via FOIA, and are indirectly referenced by the Trump EPA in its justification for the changes.In 2024, Conolly gave a presentation to the EPA science advisory committee on chemicals. SACC concluded that any level of exposure to formaldehyde increased cancer risk, though Conolly disagreed with the broader committee. In late 2025, the Trump EPA published in the Federal Register its proposed new rules that would reverse the Biden regulations. It wrote that “the majority of the information presented [by SACC]”, concluded the .3 ppm threshold was most appropriate, in part referencing Conolly’s work.The Trump EPA wrote: “.3 ppm is protective of effects for all durations, including cancer.” Doa said the EPA “cherry picked” dissenting opinions, including Conolly’s.The newly released documents show the EPA previously found Conolly’s studies were out of date, or discredited them. The agency wrote in 2024 that his research contained “model uncertainties that were too large to use in risk assessments”.In a statement to the Guardian, Connolly said he was not “impressed” with the earlier EPA critiques, and that it did not appear that the agency thoroughly considered a 2023 update to his research that he said addressed their concerns.Connolly said the Trump EPA’s changes to formaldehyde risk levels were “consistent with” his research and it is unclear which science was used to justify the changes.“Yes, I agree that formaldehyde should be regulated along the lines of the current EPA position, but I do have to wonder how they got there,” Conolly said. The EPA also heavily relied on some human studies from as far back as 1987 to develop their threshold.Conolly’s early papers were fund by the Chemical Industry Institute of Technology, a trade group, while his 2023 paper was funded by the American Chemistry Council. The American Chemistry Council’s Julianne Ogden sent an email to the EPA shortly after the February 2023 meeting pushing industry’s argument that .3 ppm of formaldehyde in the air is safe.Conolly downplayed the influence on his findings, noting that he has worked for the military and academia.“In evaluating science, what matters is the quality of the science,” Conolly said. “Saying that science is no good because it was industry funded is a cop-out.”Conflicts of interest questionsThe same industry leaders carrying out the attack on the regulations in 2022-2024 took over the EPA in 2025, documents show. They quickly went to work dismantling the formaldehyde regulations.Among them are Nancy Beck and Lynn Dekleva, former top American Chemistry Council officials now in leadership at the EPA chemical safety office. Dekleva also spent 32 years at DuPont.“The [formaldehyde] regulatory changes are happening at Beck and Dekleva’s direction, with their direct oversight and supervision, and with their approval of the final language,” said Kyla Bennett, a former EPA scientist now with the Public Employees For Responsibility non-profit. It works with whistleblowers and EPA employees to expose agency wrongdoing.The industry attacks focused on two key pieces of science underpinning the strong formaldehyde regulations.The EPA’s Integrated Risk Information System (IRIS) is the office that determined that no level of exposure to formaldehyde is safe. Until the second Trump administration, IRIS was among the most politically insulated offices in the EPA, Bennett said. It aims to do “pure science” that is not influenced by the political winds, Bennett added.IRIS’s conclusions are reviewed by the National Academy of Science Engineering and Medicine (NASEM). Abraham Lincoln established NASEM to provide independent scientific guidance to federal agencies and to review their work. It is also politically insulated and composed of many of the nation’s foremost independent scientists, academics and industry players.A NASEM committee wrote in 2024 that it “concurred” with IRIS’s conclusion that no level of formaldehyde exposure was safe, finding it “appropriate and acceptable”. The EPA’s findings were “consistent with EPA’s state-of-practice methods”.Documents show many examples of the industry taking aim at NASEM’s and IRIS’s findings. At the February 2023 meeting, the American Chemistry Council argued that there was robust scientific agreement that IRIS’s assessment contained “deficiencies”.This directly contradicted what NASEM wrote, Doa said. And she found significant conflicts of interest in 11 of the 15 scientists industry cited in its presentation. Among them is Harvey Checkoway, who receives research funding from the American Chemistry Council, Aluminum Company of America, Dupont, Materion and Monsanto, among other industry clients.Checkoway did not respond to the Guardian’s request for comment.In other cases, the industry again “cherry-picked” data, Doa said, noting a 2022 Dekleva letter to the EPA, while Dekleva was still at the American Chemistry Council. It claimed IRIS “implied” that .3 ppm was a safe level of exposure, which Doa said overtly contradicts IRIS’s findings.Dekleva repeatedly cites in the letter Conolly’s 15-year-old science that the agency had since found was out of date or too uncertain. In its justification for undoing the rules that were published on the Federal Register, the Trump EPA wrote that it “revisited” the IRIS assessment and is “no longer relying on the EPA IRIS”.The distortion of NASEM’s conclusion also appeared in the Federal Register and EPA’s December 2025 announcement. It wrote that it had reviewed NASEM and other scientific bodies’ comments, and was “following their recommendations and focusing on the science”.Olson is calling on Congress to investigate these types of issues and the broader industry takeover of the EPA.“It sounds like insider baseball, but it has very real implications for people exposed to these chemicals and for people’s pocketbooks,” Olson said. “We’re going to pay for this through the nose for our taxes and insurance bills.”