The U.S. Environmental Protection Agency announced an emergency order this week suspending all use of an herbicide known to cause irreversible developmental damage to human fetuses.
The now-banned pesticide — dimethyl tetrachloroterephthalate, or DCPA, marketed under the trade name Dacthal — stops the growth of certain annual grasses and weeds, and was registered for use with broccoli, Brussels sprouts, cabbage, and onions, among other crops, as well as turf. But mounting evidence has shown the chemical is dangerous to people — ”so dangerous that it needs to be removed from the market immediately,” as Michael Freedhoff, assistant administrator for the EPA’s Office of Chemical Safety and Pollution Prevention, said in a statement.
As of Tuesday, farmers won’t be able to buy more DCPA or use up their existing stock. It’s the first time in nearly 40 years that the EPA has exercised this emergency authority for a pesticide.
Farmworker unions and advocacy organizations are hailing the decision as a major victory for environmental justice, as pregnant people working on farms can be exposed to DCPA levels between 4 and 20 times higher than what the EPA estimates is safe. Nearly 80 percent of farmworkers nationally identify as Hispanic, while 70 percent are foreign born, and 20 percent of agricultural worker families live below the federal poverty line. Economic precarity, language barriers, and fear of being reported to immigration authorities can make it difficult for farmworkers to push back against dangerous working conditions.
“The EPA’s order will protect farmworker women and girls who bear the heavy and dangerous burden of pesticide exposure every day,” Mily Treviño-Sauceda, executive director of Alianza Nacional de Campesinas, an organization of female farmworkers, said in a statement. “It will spare their children lifelong harm when they are growing food to ensure families around the country have food on their tables.”
The EPA’s decision is the result of a regular review process conducted every 15 years to ensure registered pesticides cause “no unreasonable adverse effects on humans and the environment.”
For DCPA, the EPA gathered toxicity data from the AMVAC Chemical Corporation, DCPA’s only manufacturer, between 2013 and 2023. After receiving a long-awaited study on the herbicide’s effects on fetal thyroid development, the EPA said last year that there were serious health risks to people handling the chemical or working in areas where it has been used.
Although DCPA product labels warned workers not to enter treated fields for 12 hours after the chemical was applied, EPA found that, in many cases, fields remained too dangerous to enter for periods of 25 days or more. A phenomenon called “spray drift,” where pesticides float from the point of application to other fields or neighborhoods, also posed potentially unmitigable risks to human health.
In April, the EPA issued a warning to farmworkers about the “serious, permanent, and irreversible health risks” associated with DCPA — including concerns that the chemical could induce changes to fetal thyroid hormone levels, which are linked to low birth weight and impaired brain development, and motor skills. AMVAC voluntarily canceled DCPA registrations for use on turf in December 2023, but the EPA said the company’s proposals to mitigate the chemical’s many health risks were inadequate. The agency notified AMVAC earlier this year that it would be taking regulatory action “as soon as practicable” under the Federal Insecticide, Fungicide, and Rodenticide Act, or FIFRA.
Under less urgent circumstances, that might have meant issuing a cancellation order but then keeping DPCA on the market for several months or even years while the agency fulfilled procedural requirements like collecting input from stakeholders and the public and negotiating with the product manufacturer. In this case, however, the EPA said the risks were so great that it could suspend DCPA while those cancellation proceedings unfolded.
The AMVAC Chemical Corporation did not respond to Grist’s request for comment.
Amy van Saun, a senior attorney for the nonprofit Center for Food Safety, commended the EPA’s decision to no only stop the sale of DCPA but order companies not to use the Dacthal they already have on hand: “No more sale or transport unless you’re giving it back to the manufacturer to dispose of,” she said. “If the EPA does a good job of telling everybody that this is happening, that you can no longer use this, then farmworkers who are working around [DCPA] will immediately not have to be exposed anymore.”
She added that farmworkers represent the “backbone” of the United States’ agricultural system but have historically “been treated extremely unfairly.”
Anne Katten, director of the Pesticide and Worker Safety Project at the nonprofit California Rural Legal Assistance Foundation, said the suspension will also protect farmworkers’ families. “It’s often very hard to completely eliminate take-home exposures,” she said, explaining how DCPA can cling to field workers’ clothing and follow them home. Farmworkers are generally concerned about pesticide exposures, Katten added, but they often don’t know which ones have been applied to the fields where they work.
Katten and van Saun said they’re now eager to see the EPA use its authority to suspend other toxic pesticides, including paraquat and the weed killer glyphosate — known by the brand name Roundup. Long-term exposure to paraquat, which is banned in the European Union, has been linked to Parkinson’s; some studies link glyphosate to cancer, as well as liver and kidney damage. In 2021, the EPA banned the pesticide chlorpyrifos after research linked it to neurological damage in children.
“We really encourage EPA to keep doing this,” van Saun said. “We hope they continue to cancel more pesticides that are harming people’s health.”
