WASHINGTON — A coalition of conservation and public health advocacy organizations has filed a lawsuit challenging the U.S. Environmental Protection Agency’s approval of isocycloseram, a newly authorized insecticide that plaintiffs describe as a “forever chemical” due to its classification as a highly persistent PFAS compound.
The legal challenge, filed in U.S. District Court for the District of Columbia, targets the EPA’s decision to approve the pesticide for widespread use on golf courses, residential lawns and a long list of food crops. Those crops include apples, oranges, lettuce, spinach, tomatoes, broccoli, bell peppers, cucumbers, peaches, almonds, wheat and oats—applications that would place the chemical across millions of acres of agricultural and recreational land.
PFAS, or per- and polyfluoroalkyl substances, are often referred to as “forever chemicals” because they can persist for long periods in the environment and may accumulate in soil, water and living organisms. The groups behind the lawsuit argue that allowing a PFAS-based pesticide into broad commercial use increases the likelihood of long-term contamination risks, particularly when the chemical is used directly on food crops.
According to the lawsuit, the EPA’s own review identified serious health concerns tied to isocycloseram, including reproductive and organ impacts observed in animal studies sponsored by the pesticide’s manufacturer. The agency found that the chemical reduced testicle size, lowered sperm counts and harmed the liver in those studies.
The complaint also points to international regulatory findings that differ from the EPA’s conclusions. Australian regulators determined that the pesticide induced skeletal malformations in fetal rats, an outcome the EPA denied, according to the groups. The plaintiffs further claim that there is evidence isocycloseram poses a cancer risk, and argue the agency failed to properly address that risk during its approval process.
“EPA itself acknowledges that the PFAS pesticide isocycloseram presents significant human health and environmental risks, yet the agency swept those risks under the rug,” said Sharmeen Morrison, senior attorney at Earthjustice. “In doing so, the agency’s approval of this pesticide violated federal law. Isocycloseram does not belong on millions of acres of American farmland that produces the food we eat.”
Beyond human health concerns, the lawsuit also raises alarms about the pesticide’s potential impact on pollinators. The plaintiffs say isocycloseram is highly toxic to bees and other pollinating insects that are essential to agricultural productivity and biodiversity.
The EPA found that pollinators could be exposed to 1,500 times the lethal level of the pesticide by collecting nectar and pollen near treated fields, the groups said. Pollinator exposure has become an increasingly sensitive issue for regulators and agricultural producers, given the direct link between insect populations and crop yields.
The lawsuit also points to the role pollinators play in food supply chains. One out of every three bites of food consumed depends on plants pollinated by bees and other animals, the groups noted, including many nutrient-dense fruits and vegetables that make up core parts of North American diets.
In addition to pollinator impacts, the EPA is said to have predicted significant adverse effects on more than 1,000 threatened and endangered species. The plaintiffs argue that those risks are particularly troubling given existing pressures on already vulnerable wildlife populations, including fish and birds.
“Approval of this dangerous pesticide spotlights how the industry puppet masters running the EPA chemicals office are making a mockery of chemical oversight,” said Nathan Donley, environmental health science director at the Center for Biological Diversity. “We’re going to fight like hell to make sure these forever pesticides aren’t allowed to poison our grandchildren’s grandchildren.”
The legal filing also highlights what the groups describe as a troubling overlap between pesticide regulation and industry influence inside the EPA’s Office of Chemical Safety and Pollution Prevention. The lawsuit notes that isocycloseram’s approval came months after Kyle Kunkler, identified as a former lobbyist for the pro-pesticide American Soybean Association, was appointed deputy assistant administrator for pesticides.
At the EPA, Kunkler works under two former lobbyists for the American Chemistry Council, Nancy Beck and Lynn Dekleva, according to the groups. The office is overseen by Doug Troutman, described as a fourth industry lobbyist who was recently confirmed to lead the chemicals office following an endorsement by the chemistry council.
The plaintiffs argue that the agency’s decision-making reflects a pattern of deference to industry-submitted research rather than precautionary public health oversight, particularly for chemicals that persist in the environment and may break down into additional PFAS compounds.
“EPA rubber-stamped the manufacturer’s junk science, ignoring the risk of cancer, birth defects and environmental harms of this hazardous insecticide,” said Bill Freese, science director at Center for Food Safety. “The only value ‘regulation’ of this sort has is to pesticide makers, helping them deceive the public with false assurances of safety.”
The lawsuit further alleges that the risks associated with isocycloseram may extend beyond the compound itself. While isocycloseram is persistent, the plaintiffs say it is also known to degrade into 40 smaller PFAS chemicals, some of which are even more highly persistent—raising concerns about long-term environmental loading and the potential for multiple contaminants to emerge from a single pesticide application.
With the case now before the D.C. federal court, the challenge is expected to test the EPA’s legal justification for approving a PFAS-class pesticide for widespread use, and could have broader implications for how persistent chemicals are evaluated and regulated in U.S. agriculture and environmental policy.
