On November 19, 2025, the U.S. Environmental Protection Agency (EPA) registered ten products containing isocycloseram, a new broad‑spectrum insecticide for agricultural, turf, ornamental, and consumer uses. According to data gathered from the manufacturer of isocycloseram and other sources, the insecticide may pose several environmental and health risks and could fall within broader definitions of per‑ and polyfluoroalkyl substances (PFAS). If that’s the case, why did the EPA approve a forever chemical that it acknowledges may have a deleterious effect on pollinators like bees and other endangered species?
That’s one of the questions posed by the nonprofit groups the Center for Biological Diversity and the Center for Food Safety, who are co-plaintiffs in a suit filed in the U.S. Ninth Circuit Court of Appeals on January 15, 2026. The petition seeks to have the court set aside the EPA-approved registration of isocycloseram, which it claims violates both the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Endangered Species Act (ESA). It also criticizes the Trump administration’s appointment of former pesticide industry lobbyists and allies to key EPA leadership and rulemaking roles, which the groups say has tilted decision‑making toward industry interests.
The EPA’s press release announcing the approval of isocycloseram acknowledged that it may pose some danger to pollinators and endangered species, but included safe-use practices that it insisted would mitigate the effects. It has also shared its predictions with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service. These agencies are tasked with making the actual final jeopardy/adverse modification assessment on how isocycloseram will affect the environment and public health. According to the plaintiffs, it won’t be good.
Soybeans and Cotton and Corn, Oh My!
Since its creation in 1970, the EPA has been charged with protecting human health and the environment. From keeping the air free of acid rain to ensuring our drinking water doesn’t contain toxic chemicals, the EPA has served as a watchdog against pollution and companies that put profit over environmental health. How assertively the agency carries out that mission can shift depending on the administration in power.
The EPA often has to walk a tightrope when it comes to pesticide approvals and the presence of PFAS chemicals. Highly persistent PFAS are called “forever chemicals” and don’t easily break down once introduced into the environment. In addition to adversely affecting pollinators and other endangered species, they’ve been linked to decreased fertility, damaged immune systems, children’s health issues, and cancer in animals and humans.
On the other hand, some businesses insist that herbicides and insecticides are necessary to keep pests from destroying farm crops and golf course turf. EPA Administrator Lee Zeldin has taken a business‑friendly approach during his tenure, rolling back dozens of environmental and climate protections adopted in prior administrations.
Wait, Reduced What?!?!
Produced by Syngenta, isocycloseram is a fluorinated carbon that serves as the active ingredient in several new insecticide products. It can be used directly on seeds during planting or by aerial application on certain crops. It’s also approved for indoor consumer use to eliminate pests such as bed bugs and cockroaches.
While the EPA insists that isocycloseram is a chemical product that is not a dangerous PFAS, the environmental advocacy groups bringing the lawsuit disagree. Citing an EPA study from 2025, they argue that isocycloseram can break down into 40 smaller PFAS that are much more persistent and pose significant environmental and health risks. Bees and other pollinators would face an extremely heightened risk of exposure to the lethal pesticide, and more than 1,000 threatened and endangered species would likely suffer adverse effects.
The plaintiffs also raise concerns about the potential effects isocycloseram PFAS can have on mammals. An EPA report based on Syngenta’s research showed results that included liver damage, lowered sperm count, and reduced testicle size in animal testing. Other results that suggested skeletal malformation in fetal rats and the possibility of cancer were rejected by the EPA for having flawed testing.
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