Over the past several months, decisions on new chemicals have picked up speed, including on those with potential PFAS characteristics.

Back in April, the agency proposed approving a Syngenta chemical that targets pests called nematodes for crops including Romaine lettuce and soybeans.

Then, in June, it proposed three more approvals in rapid succession: an herbicide made by Bayer for corn and soybeans; a Syngenta field-crop insecticide that can be applied as a seed treatment; and an herbicide from BASF for oranges, apples, peanuts, and other crops.

At the Center for Biological Diversity, Donley and his team analyzed all four and determined that, based on their chemical structure, all are PFAS, according to the definition created by the Organisation for Economic Co-operation and Development (OECD).

That worries Donley because, he said, the definition was based on “the chemical components that make something incredibly persistent.” While the new pesticides are shorter-chain molecules compared to the other longer-chain molecules, they could still stick around in the environment for decades or even centuries due to their durable carbon-fluorine bonds and can break down into other chemicals like trifluoroacetic acid (TFA) that also persist.

“All PFAS are persistent. That is one of the things that they all have in common,” PEER’s Bennett said.

Syngenta and BASF did not respond to questions about the new chemicals qualifying as PFAS and whether that should prompt concerns around persistence or potential human health impacts. A Bayer spokesperson sent an emailed statement that pointed to the fact that its new herbicide, called diflufenican, is “not a PFAS substance” according to the EPA.

“We stand behind the safety of our products, which have been tested extensively and thoroughly reviewed by regulators,” the statement read. “Diflufenican will be an important weed-control tool for farmers and has been thoroughly reviewed by the U.S. Environmental Protection Agency (EPA) to ensure the product can be used safely for people and the environment when they are used according to label instructions.”

In January, industry trade associations CropLife America and Responsible Industry for a Sound Environment (which operate under the same federally registered nonprofit) also submitted comments that provide insight into the industry’s broader perspective on the issue.

In a letter regarding new rules Maine is implementing that will ban products containing PFAS, executives argued against the use of the broader OECD definition of PFAS currently adopted by the state. That definition “disregards the remarkably different physical, chemical, and biological properties that shape the potential human and ecological risk profiles of chemistries that meet that definition.”

They also emphasized that when the EPA approves a new product, it must determine the pesticide will not cause “unreasonable adverse effects” to the environment or human health when used according to the label. Finally, the executives wrote, “the use of PFAS in certain pesticides is essential to their function.”

Demands for More Research and a Common Definition

But new chemicals do not have as much scientific data on them, Donley said. “We have a little bit here and there that says maybe they’re safe,” he said. “But eventually, more science is going to come out.” Studies have shown the shorter-chain PFAS are already prevalent inside homes and bodies in the U.S. And because of their potential to persist in the environment, by the time we learn about their dangers, it may be too late.

“If you’ve got something that sticks around for generations, then any new science that comes out in the next two years or five years or 10 years saying this stuff is more dangerous than we thought, it’s irreversible,” he said. “We estimate we’re releasing about 30 million pounds of short- and ultra-short-chain pesticide PFAS right now each year in the U.S., and we still have very little idea of what is happening to them in the environment and what their true toxicities are.”

To make a similar point, Bennett gave the example of GenX, a PFAS that DuPont introduced in 2009 as a safer replacement for PFOA in commercial products.

DuPont dumped the chemical into North Carolina’s Cape Fear River, leading to devastating contamination that affected millions of people. It is now clear that GenX requires long periods of time to break down, and the chemical is associated with serious health effects, including liver problems and cancer. In May, the EPA eliminated its first limits on GenX in drinking water, set during the Biden administration, and is currently re-reviewing them.

“One thing that EPA keeps forgetting is that the absence of evidence is not the evidence of absence,” Bennett said. “In other words, just because we don’t have the studies and the data doesn’t mean it’s safe. It means we just don’t know yet.”

Given there is evidence pointing to potential health risks and environmental persistence, she said, the EPA should err on the side of caution.

But this “precautionary principle,” much touted by MAHA supporters, doesn’t square with the Trump administration’s broader deregulatory push.

Truly addressing PFAS in the food system, Bennett said, would involve the EPA first adopting the broader definition set by the OECD and regulating those chemicals as a class. That kind of policy would end the registration of persistent, harmful pesticides and even lead to safer drinking-water standards.

Hearing Kennedy, a member of the administration, acknowledging the chemicals’ harms made her angry, she said. “You know it’s dangerous to people, especially children,” she said. “If they’re spraying it on our food, it’s in our water. What are you doing to stop it? The answer is nothing. They’re doing nothing to stop it.”