28
Aug
Rejecting Clear Pesticide Label Restrictions, EPA Leaves Protection of Endangered Species Up to Applicators
(Beyond Pesticides, August 28, 2025) The U.S. Environmental Protection Agency (EPA) on August 12, 2025, released a statement, “EPA Announces Action to Protect Endangered Species from Insecticide Methomyl,†in which the agency announced label changes for methomyl, a carbamate insecticide, with mitigation measures that are being criticized as allowing great risks to biodiversity and human health. The label changes, following the National Marine Fisheries Service’s (NMFS) final biological opinion issued on January 1, 2024, actually establish mitigation measures to be determined by applicators using the Bulletins Live! Two website prior to use. EPA claims that this grower determined action will meet the standards of the Endangered Species Act (ESA) by “reduc[ing] runoff and spray drift from treated areas into species’ habitats.†However, the process does include monitoring and oversight to determine whether the rigorous standards of ESA are being met. The agency says that mitigation tracking is “at the field or farm level,†but it is not required to be submitted to the agency.
EPA announced on August 20 that it is holding a 90-minute public webinar on September 16, 2025, at 2:00 PM ET to provide information on the ecological runoff/erosion and spray drift mitigation measures that can be used to protect endangered species from pesticides. Register here.
As also shared in the methomyl announcement: “In addition to the measures required by NMFS, EPA approved an action initiated by a methomyl registrant to reclassify the last remaining non-restricted use pesticide (RUP) methomyl product as a RUP. All methomyl products are RUPs and may only be applied by certified applicators.†While this classification acknowledges methomyl’s toxicity and heightened risks in not allowing the general public to purchase or apply products containing the active ingredient, it allows application by a certified pesticide applicator or an individual working under their direct supervision, in which on-site supervision is not required—an allowance that has been widely criticized as insufficient to ensure safety protection.
Covered in a previous Daily News, improper handling of RUPs can lead to death. Four children, ages 7-17, died after a toxic RUP was illegally applied under their house in Amarillo, Texas. This incident is one of many that demonstrate the deficiency of managing risks of highly toxic chemicals by labeling them “restricted use.†It has been Beyond Pesticides’ position that chemicals with acute and chronic toxicity should not be available on the market, even with restrictions. When regulatory determinations are made, the reality of misuse, accidents, and compliance under 100% with label instructions is not considered, thus endangering health and the environment.
EPA’s biological evaluation for methomyl in 2021 determined that “use of the pesticide according to label instructions was ‘likely to adversely affect’ at least one animal or plant for 1,098 listed species and 281 designated critical habitats.†After consulting with NMFS, the agency developed its own biological opinion in 2024 for methomyl, only covering species under NMFS’s purview, and “concluded that the use of methomyl is ‘likely to adversely affect’ 61 species and 56 critical habitats.â€
NMFS’s conclusions, with the substantially lower numbers for species and critical habitats likely to experience adverse effects, led to the current label changes and mitigation measures. EPA states, “NMFS determined that, with the inclusion of mitigation measures, the registered uses of methomyl will not result in jeopardy determinations for species under NMFS jurisdiction.†  Â
The prediction that no jeopardy or adverse effects will occur for listed species or designated critical habitats relies solely on the successful implementation of mitigation measures with the use of products containing methomyl. However, as stated, this strategy does not properly ensure that these measures are followed, as there is no enforcement or accountability required from applicators.
Additionally, these mitigations are outlined on EPA’s mitigation menu website, which users in a test run reported navigating is so cumbersome and convoluted that the agency cannot ensure that it can be taught, implemented, or enforced. The system uses a point system to determine sufficient mitigation to allow pesticide use. However, the expectation of accurate calculations for mitigation measures is placed on applicators who may not be fully versed in math or English. The users in the test complained of technological problems with the website, while also commenting on the complexities involved in the process.
On this topic of mitigation, Beyond Pesticides, in Daily News EPA “Mitigation Menu†Called Complex, Raising Doubts about Required Endangered Species Protection, continues in saying advocates of organic agriculture argue that instead of spending millions of dollars and many years creating mitigation programs that are unenforceable and ineffective, EPA should spend the same amount of time and money supporting farmers in the transition to organic agriculture and in exiting the toxic pesticide treadmill.
Even if the mitigation menu were easier to navigate, these proposed mitigation measures only lessen the chance of harmful impacts of pesticide use and, more concerning, are entirely voluntary. There is no enforcement mechanism and no way to ensure that the pesticides are used as directed or that mitigation measures are implemented properly. Added complexity does not equate with added safety, say environmental advocates, concluding that the current proposed mitigation measures for methomyl are insufficient to protect the health of wildlife, as well as public health and the environment.
Methomyl, as seen in Beyond Pesticides’ Gateway on Pesticide Hazards and Safe Pest Management, is linked to endocrine disruption, neurotoxicity, and kidney/liver damage, among other adverse effects. In this year alone, Daily News coverage of scientific literature associates methomyl with sleep disorders and DNA/cellular damage in farmers and farmworkers, as well as reproductive system effects such as heavy menstrual bleeding in adolescents with prenatal exposure. (See the methomyl Daily News archive here.)
Further highlighting the risks associated with exposure to methomyl, recent research published in the last month shows cardiovascular effects in aquatic organisms and toxicity to consumers of chlorine-treated drinking water.
In Science of The Total Environment, the study authors show in zebrafish larvae that methomyl induces developmental malformations, triggers cardiac toxicity, inhibits normal development of the vascular system, activates immune responses, and increases oxidative stress. To confirm that the vascular toxicity is applicable to humans as well, the researchers use human umbilical vein endothelial cells (HUVECs) as an in vitro model and also find adverse effects. “These findings provide novel insights into the environmental and toxicological effects of methomyl and highlight its potential risk of accumulation in aquatic systems,†the authors conclude.
In Water Research, the interaction between methomyl and its transformation products with chlorine, widely used as a disinfectant during the treatment of drinking water, is investigated for direct and indirect toxicity. Both methomyl and its transformation products have the same mode of action and inhibit acetylcholinesterase (AChE).
“Here, we investigated changes in anti-AChE activity during chlorination of a solution containing methomyl, a carbamate insecticide,†the study authors say. They continue, “The activity was assessed in the presence (indirect toxicity) and absence (direct toxicity) of metabolic activation.†As a result, chlorinated samples retain both direct and indirect toxicities, with the indirect toxicity attributable solely to residual methomyl and direct toxicity originating from residual methomyl and two transformation products.
Both of these recent studies are pertinent, as pesticides used in agriculture and landscape management are transported to water bodies in runoff. Not only does this directly expose aquatic organisms, but river water is often used in treatment plants as a source of drinking water. (See studies here, here, and here.)
“[S]ince most pesticides are not effectively removed by conventional treatment processes, they can remain in the treated water, even after the final addition of free chlorine for disinfection,†the researchers say. “Consequently, they can react with the free chlorine, leading to the formation of various transformation products (TPs) [that] can be toxic.†(See additional research here, here, and here.)
Organic practices offer a holistic approach to sustainable agriculture and land management. Instead of allowing the use of petrochemical pesticides and synthetic fertilizers that contain active ingredients with documented toxicity, like methomyl, and relying on unenforceable mitigation measures to “protect endangered species,†the organic solution is documented to be profitable and with higher crop yield, protects and enhances biodiversity, increases soil benefits, provides health benefits to those who adopt an organic diet, and mitigates climate change, among others.
Learn more about the health and environmental benefits of organic here and here. Sign up to get Action of the Week and Weekly News Update emails sent directly to your inbox here, and become a Parks Advocate through the Parks for a Sustainable Future program to get involved in your community’s transition to organic.      Â
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources:
Lee, H. et al. (2025) Methomyl-induced developmental and cardiovascular toxicity in zebrafish via immune response, oxidative stress, and apoptosis, Science of The Total Environment. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0048969725018558.
Matsushita, T. et al. (2025) Methomyl, a carbamate insecticide, forms oxygenated transformation products that inhibit acetylcholinesterase upon chlorination, Water Research. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0043135425009765.
U.S. Environmental Protection Agency (2025). EPA Announces Action to Protect Endangered Species from Insecticide Methomyl. Available at: https://www.epa.gov/pesticides/epa-announces-action-protect-endangered-species-insecticide-methomyl.
