15
May
United Nations Lists Neurotoxic Insecticide Chlorpyrifos for Elimination, Exempt Uses Criticized
(Beyond Pesticides, May 15, 2025) The United Nations’ Conference of Parties (COP) for the Stockholm Convention on Persistent Organic Pollutants (POPs), originally adopted by 128 countries in 2001, voted to move the highly neurotoxic organophosphate insecticide chlorpyrifos, linked to brain damage in children, to Annex A (Elimination) with exemptions on a range of crops, control for ticks for cattle, and wood preservation, according to the POPs Review Committee. The exemptions drew criticism from groups seeking to eliminate chlorpyrifos without exemptions, as had been originally proposed. In the world of pesticide restrictions, this POPs classification marks a step forward in the international regulation of chlorpyrifos, as the U.S. sits on the sidelines. The long effort to ban this one hazardous pesticide, as important as the action is, serves as a reminder of the limitations of a whack-a-mole approach to chemical regulation of the thousands of toxic products poisoning people and the planet, filled with compromises to public health and the environment—while alternative practices and materials are available to meet productivity, profitability, and quality of life goals.
According to Down to Earth, the 18 specific crop and use exemptions include the following:
Barley (termites), Cabbage (diamondback moth), Cacao (cacao-mosquitoes and cacao pod borer), Chickpea (cutworms), Citrus (scale insects), Cotton and cotton seed (aphids, carpophagous caterpillars, cutworms, spider mites, cotton leaf roller, whitefly larvae, whitefly adults), Eggplant (shoot and fruit borer), Maize (armyworms, lesser cornstalk borer, cutworm, corn earworm, grubs, seedling flies, stem borer, green stink bug), Onion (root grubs), Peanut (white grubs), Pineapple (mealybug, pineapple weevil, glasshouse symphylid), Rapeseed (crucifer flea beetles, turnip sawflies, common pollen beetles, turnip gall weevils), Rice (rice planthoppers, rice stemborers, rice leaf rollers), Sorghum (armyworms, lesser cornstalk borer), Soya bean (Armyworm, soybean pod borer, soybean seed fly, soybean leaf beetle, tobacco whitefly, soybean aphid, spiraling whitefly, green stink bug, brown stink bug and spider mite), Sugarcane (termites, beetles, grubs, sugarcane top borer, and sugarcane stem borer), Teff (termites), and Wheat (termites, corn bugs, wheat chafers, leaf beetles, aphids, and thrips).
Despite the compromises, putting chlorpyrifos on the POPs Annex A list sets a course for  “global elimination of uses of this highly hazardous pesticide,†according to a May 4 press release by Pesticide Action Network International. “The COP took an important step today toward protecting human health and the environment from chemicals linked to serious health conditions and threats to biodiversity,†said Sara Brosché, PhD, science advisor with the International Pollutants Elimination Network (IPEN). “But we are disappointed that financial interests caused unnecessary and dangerous exemptions that will lead to ongoing toxic exposures.’â€
 “We should not allow continued uses of the most dangerous chemicals known,†said Pamela Miller, co-chair of IPEN and executive director of Alaska Community Action on Toxics. Ms. Miller continued, “The work of the Convention and its expert committee has been undermined this week with the extensive number of exemptions introduced. Science must be the foundation of the Convention’s decisions, which must meet the Convention’s intent to protect the health of women, children, workers, Indigenous peoples, and future generations.â€
Stockholm Convention
The Stockholm Convention is “a global treaty to protect human health and the environment from chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of humans and wildlife, and have harmful impacts on human health or on the environment,†according to the website of the Secretariat of the Stockholm Convention. This United Nations treaty has now been ratified by 152 nations and includes 186 nations. It is important to note that the United States has not ratified the treaty, despite decades of advocacy urging the U.S. Senate to take action. (See here and here for the latest action in 2023.)
POPs are widely viewed as an existential threat to human and ecological health due to their chemical properties. For example, POPs are generally regarded to have longer half-lives than other families of pesticides and therefore persist in the environment with the threat of chronic effects. POPs are also widely distributed throughout the environment. Like many other synthetic pesticides that easily leach onto other molecules and compounds, POPs bioaccumulate and biomagnify as they move through the food chain and are toxic to humans and wildlife. POPs are linked to adverse immune system effects, reproductive disorders, and population declines in birds, fish, and other species. They are associated with reproductive, developmental, behavioral, neurological, endocrine, and immunological health effects in humans.Â
Chlorpyrifos’s inclusion in Annex A is noteworthy because Article 3 of this Convention requires each country to “[p]rohibit and/or eliminate the production and use, as well as the import and export, of the intentionally produced POPs that are listed in†this section. This international assessment plays an important role in protecting health and safety worldwide, given the abundance of peer-reviewed scientific research defining the health and environmental threats from pesticides and deficiencies in nation’s regulatory review, such as the U.S. Environmental Protection Agency’s (EPA) failure to fully implement the Endocrine Disruptor Screening Program to regulate pesticides with endocrine-disrupting potential. (See Daily News, and associated actions, here.) Despite the gaps and implementation challenges, cohorts of nations continue to find ways to take action and raise revenue to implement the mission of the Stockholm Convention. (See Daily News here.)
See here for more Daily News coverage on the Stockholm Convention.
Chlorpyrifos History in U.S.
In May 2021, a three-judge panel of the Ninth Circuit Court of Appeals instructed EPA to either revoke the tolerances the agency had set for chlorpyrifos’s residue in various foods or demonstrate that they meet the statutory and regulatory standards. Finally capitulating after 21 years of delay, EPA issued a final rule in August 2021 revoking all food tolerances for the neurotoxicant.
This seemed to signal a step in the right direction in after relentless grassroots advocacy and judicial oversight prompted regulatory action until February 2022, when a different set of petitioners—pesticide corporations, groups representing industrial agriculture, and other countries’ agricultural interests vested in fossil fuel-dependent food systems—filed an action in the Eighth Circuit Court of Appeals. On November 3 of this year, a three-judge panel of the Eighth Circuit reversed EPA’s momentous 2021 decision, rendering the Ninth Circuit’s opinion moot.
As demonstrated historically with chlordane, dicamba, methyl iodide, and atrazine, among other notoriously hazardous pesticides, EPA’s decision-making, delay, and contradictory policies are not confined to chlorpyrifos. In fact, when EPA negotiated in 2000 a withdrawal from the market of residential uses of chlorpyrifos, based on the neurotoxic impacts on children, it allowed the chemical corporation Dow Chemical to sell off all its existing stocks over a one-year period. “Chlorpyrifos, glyphosate, 2,4-D, atrazine, and many others are poster children for a failed regulatory system that props up chemical-intensive agriculture despite the availability of alternative organic practices not reliant on these toxic chemicals,†says Jay Feldman, executive director of Beyond Pesticides.Â
Ironically, as in the short interval between EPA’s rule banning agricultural uses of chlorpyrifos and the Eighth Circuit’s intervention, “the need for any use of chlorpyrifos has been refuted,†Earthjustice Senior Attorney Patti Goldman noted in a 2023 press release. “Crops have been successfully grown in the two years since chlorpyrifos has been banned,†Ms. Goldman said. (See additional Daily News coverage and additional commentary on the saga of chlorpyrifos litigation and regulations here, here, here, and here.)
In the face of federal inaction, Attorneys General of New York, California, Hawaii, Maryland, Massachusetts, Oregon, Vermont, Washington, and Washington, D.C., in a legal petition, are calling on EPA to “revoke all tolerances for residues of the organophosphate pesticide chlorpyrifos except those associated with its use on 11 crops—alfalfa, apple, asparagus, tart cherry, citrus, cotton, peach, soybean, strawberry, sugar beet, and wheat—and, with respect to those 11 crops, purports to make a determination of safety supporting the tolerances that are not revoked.â€
The petition follows a public comment period ending in March 2025 on the revocation of chlorpyrifos tolerances for all uses except 11 specific crops—one of the last actions of the Biden Administration’s EPA on pesticide regulations after the consequential 2023 Eight Circuit Court of Appeals loss and setbacks across multiple administrations going back to the Clinton Administration. Beyond Pesticides, citing alternatives and the clear weight of evidence on neurological and a suite of health impacts, submitted comments calling for the total cancellation of chlorpyrifos use.
For further history on regulatory actions, analysis of peer-reviewed studies, and additional information on chlorpyrifos, see here for its Daily News section. See Pesticides and You, Abandoning Science: A look at the failure to regulate the neurotoxic insecticide chlorpyrifos, for additional commentary and analysis.
Adverse Health Effects
Some of the latest peer-reviewed research on chlorpyrifos reveals additional threats to the immune system and male reproductive health that are not currently captured in what would otherwise be considered up-to-date EPA risk assessments of this active ingredient. (See Daily News here.)
Chlorpyrifos has been linked to endocrine disruption, including obesity. A systematic review of studies on endocrine-disrupting chemicals (EDCs) affecting  body weight evaluated 36 clinical and preclinical studies and links agricultural pesticidal uses to obesity (9 of these studies specifically tested for linkages to chlorpyrifos as an EDCs). The authors, with the lead researchers from the School of Medicine and Health Sciences at Catholic University of Valencia San Vincente, Valencia, Spain, assess studies on a range of pesticides, including organophosphates, pyrethroids, neonicotinoids, and others. In addition to concluding that the EDCs promote obesity, they report that the chemicals cause “other anthropometric changes by altering lipid and glucose metabolism, modifying genes, or altering hormone levels such as leptin.â€
The insecticide also impacts ecosystem stability, with recent studies finding pesticide-induced alterations in the gut microbiota of a farmland raptor species (see Daily News here), among other deleterious health impacts on crustaceans, rodents, Monarch butterflies, and other forms of wildlife.
See here for a comprehensive listing of adverse health and ecological effects for chlorpyrifos in Beyond Pesticides’ Gateway on Pesticide Hazards and Safe Pest Management.
Call to Action
Beyond Pesticides works with communities across the nation and worldwide to move beyond petrochemical pesticide and synthetic fertilizer dependency and toward organically-managed agriculture, playing fields, and public green spaces. See here to learn more about the Parks for a Sustainable Future Program, including the updated map featuring our pilot sites in 24 states.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources: PAN International, IPEN
