13
Jul
Action Asks EPA and Congress To Ban Endocrine Disrupting Pesticides Linked to Chronic Effects After SCOTUS Ruling
(Beyond Pesticides, July 13, 2026) In the wake of the June U.S. Supreme Court decision proclaiming the safety of pesticides registered with the U.S. Environmental Protection Agency (EPA) and rejecting the long-standing right of those harmed to hold chemical companies accountable for failing to warn of potential product hazards, the public is urging EPA to meet its statutory duty to test for the widespread adverse effects of endocrine disrupting pesticides. (See also here.) The endocrine system controls the development and functioning of organ systems, while pesticides that have endocrine disrupting effects are linked to cancer and a wide range of chronic adverse effects. Despite this, the 7-2 majority of Supreme Court justices finds, “EPA must evaluate a pesticide and its proposed label—and must determine that the proposed label includes all warnings necessary and adequate to protect human health and the environment, and is not false or misleading.” The court opinion goes on to say that EPA’s decision to allow the marketing of pesticide products is “prima facie” evidence of a complete and thorough review and determination of safety. In their dissent, Justices Ketanji Brown Jackson and Neil Gorsuch said, in agreement with an amicus brief filed by former top EPA officials, pesticide registration is not “conclusive” evidence of safety. The action is asking EPA and Congress to immediately implement the Endocrine Disruptor Screening Program, considering all data concerning endocrine disruption, and deny registration or reregistration of pesticides without sufficient data to demonstrate no unreasonable adverse endocrine risk.
After ongoing delays following the 1996 Congressional mandate to determine whether pesticides disrupt the endocrine system of humans and other organisms and legal victory in federal court in a case in the U.S. District Court for the Northern District of California brought by the Center for Food Safety and a collection of agricultural workers’ organizations, farmers’ groups, and pesticide activists, the U.S. Environmental Protection Agency (EPA) agreed to fulfill the mandate given to it by Congress in 1996 to test all pesticides for their endocrine disrupting effects and regulate them accordingly.
EPA is now implementing its long overdue Endocrine Disruptor Screening Program for pesticide active ingredients. It is imperative that EPA meets the mandates of the court settlement to collect data on and assess the effects of endocrine-disrupting pesticides over the next five years and to complete endocrine-disrupting assessments for 86 pesticides over the next 10 years. Moreover, EPA must ensure that no pesticide that it registers can cause endocrine disruption.
Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), a pesticide is presumed to pose an unreasonable risk until reliable data demonstrate otherwise. If the agency lacks the data and/or resources to fully evaluate endocrine risks to human health and wildlife, then the agency is obliged to suspend or deny any pesticide registration until the agency has sufficient data to demonstrate no unreasonable adverse endocrine risk.
EPA cannot develop a strategy for evaluating pesticides without understanding the history and status of endocrine disruption research, which are summarized in Beyond Pesticides’ comments on EPA’s 2023 proposal. Evidence that synthetic chemicals can mimic or otherwise interfere with natural hormones has existed for over half a century. Although early attention was given to estrogen mimics, it soon became apparent that the homeostatic function of the endocrine system—which regulates and balances physiological functions—can be disrupted at many sites and hormone systems.
Endocrine disruption as a phenomenon affecting humans and other species has been critically reviewed by several researchers and authors. A common thread weaving across these reviews is the notion that chemicals that may disrupt the endocrine systems of humans and wildlife may be pervasive in contaminating their habitats. A pandemic of endocrine-related disorders, from attention deficit and hyperactivity disorder (ADHD), autism, diabetes, obesity, childhood cancers, testicular cancer in young men, infertility, male dysgenesis syndrome, hypospadias, low sperm count, loss of semen volume and sperm quality, and increased risk of testicular and prostate cancer, can be connected with endocrine-disrupting chemicals (EDCs). All these disorders have been increasing in incidence and can be traced back to prenatal exposure to EDCs.
Endocrine pathways are largely conserved across species and, thus, are not species- or taxa- specific. It is well known that thyroid endocrinology in particular is well conserved across vertebrate taxa. This includes aspects of thyroid hormone synthesis, metabolism, and mechanisms of action. Thyroid hormones are derived from the thyroid gland through regulation of the hypothalamus-pituitary-thyroid (HPT) axis, which is controlled through a complex mechanism of positive and negative feedback regulation. Multiple pathways contribute to the synthesis of thyroid-releasing hormone, including thyroid hormone signaling through feedback mechanisms; leptin and melanocortin signaling that controls hunger and weight; body temperature regulation; and cardiovascular functioning. Each pathway directly targets thyroid-releasing hormone neurons. Based on the conservation of endocrine pathways, it is well understood that the ecological assays (the frog assay in particular) are often more sensitive and equally relevant to mammalian assays in informing risk assessors of whether a chemical can cause adverse endocrine outcomes in the human population and vice versa.
The Food Quality Production Act (FQPA) essentially amends FIFRA to ensure potential endocrine disrupting effects are considered in EPA risk assessments to fulfill the statutory mandate that a pesticide registration will not cause unreasonable adverse effects. This applies to humans and wildlife and to all pesticide chemicals as defined in FIFRA, including “all active and pesticide inert ingredients of such pesticide” (21 U.S.C. 231(q)(1)). The Safe Drinking Water Act (SDWA) adds drinking water contaminants as well.
In summary, the agency cannot limit EDSP to only humans and conventional pesticide active ingredients without violating the statutory requirements enumerated in FIFRA, FQPA, and SDWA. EPA should make use of all available scientifically relevant endocrine disruption research findings and also be wary of deviating from established international efforts for screening/testing endocrine disruptors that incorporate human and wildlife relevant studies. Recognizing that mammalian data inform potential endocrine disruption in other vertebrate taxa (avian, amphibian, fish) and vice versa, the agency should not decouple the mammalian from other vertebrate assays in EDSP screening. There are more than 50 different ecological and mammalian assays included in the Organization of Economic Cooperation and Development (OECD) Conceptual Framework for screening/testing endocrine disrupting effects, and there are additional assays being developed for consideration as well. So, the agency should not limit the range or types of data to be used, but as FQPA prescribes use “appropriate validated test systems and other scientifically relevant information.” While currently required data may meet the needs of human risk assessment, it is inadequate to evaluate endocrine effects on wildlife species. Additionally, it is not the agency but pesticide registrants that have the burden to demonstrate with adequate data that their products will not pose unreasonable adverse effects, including the inherently presumed endocrine disrupting effects.
The action is calling on Congress and EPA to immediately implement the Endocrine Disruptor Screening Program, considering all data concerning endocrine disruption, and deny registration or reregistration of pesticides without sufficient data to demonstrate no unreasonable adverse endocrine risk.
Letter to EPA:
As EPA implements its long overdue Endocrine Disruptor Screening Program for pesticide active ingredients, it must meet the mandates of the court settlement to collect data on and assess the effects of endocrine-disrupting pesticides over the next five years and to complete endocrine-disrupting assessments for 86 pesticides over the next 10 years. Moreover, EPA must ensure that no pesticide can cause endocrine disruption.
EPA’s strategy for evaluating pesticides requires understanding the history and status of endocrine disruption research. Evidence that synthetic chemicals can interfere with natural hormones has existed for over half a century. Although early attention was given to estrogen mimics, it was soon apparent that the homeostatic function of the endocrine system can be disrupted at many sites and hormone systems.
Many authors have documented that endocrine-disrupting chemicals (EDCs) may be pervasive in contaminating the ecosphere. A pandemic of endocrine-related disorders—attention deficit and hyperactivity disorder (ADHD), autism, diabetes, obesity, childhood cancers, testicular cancer in young men, infertility, male dysgenesis syndrome, hypospadias, low sperm count, loss of semen volume and sperm quality, and increased risk of testicular and prostate cancer—may be related to EDCs.
Endocrine pathways are largely conserved across species and thus are not species- or taxa- specific. Therefore, it is well understood that the ecological assays (the frog assay in particular) are often more sensitive and equally relevant to mammalian assays in determining whether a chemical can perturb and cause adverse endocrine outcomes in the human population and vice versa.
In summary, EPA cannot limit EDSP to only humans and conventional pesticide active ingredients without violating the statutory requirements of FIFRA, FQPA, and SDWA. EPA must use all available scientifically relevant endocrine disruption research findings and avoid deviating from established international efforts that incorporate human and wildlife studies. Recognizing that mammalian data inform potential endocrine disruption in other vertebrates (avian, amphibian, fish) and vice versa, the agency should not decouple the mammalian from other vertebrate assays in EDSP screening. With more than 50 different ecological and mammalian assays included in the Organization of Economic Cooperation and Development Conceptual Framework for screening/testing endocrine disrupting effects and additional assays in development, EPA must not limit the range or types of data to be used, but as FQPA prescribes, use “appropriate validated test systems and other scientifically relevant information.” Currently required data may meet the needs of human risk assessment but is inadequate to evaluate endocrine effects on wildlife species.
FQPA amends FIFRA to ensure potential endocrine disrupting effects are considered in risk assessments to fulfill the FIFRA mandate that pesticide use will not cause unreasonable adverse effects. This applies to humans and wildlife and to all pesticide chemicals as defined in FIFRA including all active and inert ingredients. Under FIFRA, a pesticide is presumed to pose an unreasonable risk until reliable data demonstrate otherwise. If EPA lacks the data and/or resources to fully evaluate endocrine risks to human health and wildlife, then the agency is obliged to suspend or deny any pesticide registration until the agency has sufficient data to demonstrate no unreasonable adverse endocrine risk.
Thank you.
Letter to U.S. Representative and Senators:
Please ensure that, as EPA implements its long overdue Endocrine Disruptor Screening Program for pesticide active ingredients, it meets the mandates of the court settlement to collect data on and assess the effects of endocrine-disrupting pesticides over the next five years and to complete endocrine-disrupting assessments for 86 pesticides over the next 10 years. Moreover, EPA must ensure that no pesticide can cause endocrine disruption.
EPA’s strategy for evaluating pesticides requires understanding the history and status of endocrine disruption research. Evidence that synthetic chemicals can interfere with natural hormones has existed for over half a century. Although early attention was given to estrogen mimics, it was soon apparent that the homeostatic function of the endocrine system can be disrupted at many sites and hormone systems.
Many authors have documented that endocrine-disrupting chemicals (EDCs) may be pervasive in contaminating the ecosphere. A pandemic of endocrine-related disorders—attention deficit and hyperactivity disorder (ADHD), autism, diabetes, obesity, childhood cancers, testicular cancer in young men, infertility, male dysgenesis syndrome, hypospadias, low sperm count, loss of semen volume and sperm quality, and increased risk of testicular and prostate cancer—may be related to EDCs.
Endocrine pathways are largely conserved across species and thus are not species- or taxa- specific. Therefore, it is well understood that the ecological assays (the frog assay in particular) are often more sensitive and equally relevant to mammalian assays in determining whether a chemical can perturb and cause adverse endocrine outcomes in the human population and vice versa.
In summary, EPA cannot limit EDSP to only humans and conventional pesticide active ingredients without violating the statutory requirements of FIFRA, FQPA, and SDWA. EPA must use all available scientifically relevant endocrine disruption research findings and avoid deviating from established international efforts that incorporate human and wildlife studies. Recognizing that mammalian data inform potential endocrine disruption in other vertebrates (avian, amphibian, fish) and vice versa, the agency should not decouple the mammalian from other vertebrate assays in EDSP screening. With more than 50 different ecological and mammalian assays included in the Organization of Economic Cooperation and Development Conceptual Framework for screening/testing endocrine disrupting effects and additional assays in development, EPA must not limit the range or types of data to be used, but as FQPA prescribes, use “appropriate validated test systems and other scientifically relevant information.” Currently required data may meet the needs of human risk assessment but is inadequate to evaluate endocrine effects on wildlife species.
FQPA amends FIFRA to ensure potential endocrine disrupting effects are considered in risk assessments to fulfill the FIFRA mandate that pesticide use will not cause unreasonable adverse effects. This applies to humans and wildlife and to all pesticide chemicals as defined in FIFRA, including all active and inert ingredients. Under FIFRA, a pesticide is presumed to pose an unreasonable risk until reliable data demonstrate otherwise. If EPA lacks the data and/or resources to fully evaluate endocrine risks to human health and wildlife, then the agency is obliged to suspend or deny any pesticide registration until the agency has sufficient data to demonstrate no unreasonable adverse endocrine risk.
Thank you.
