Anemic EPA announcement warning farmworkers of health risks of pesticide DCPA doesn’t go far enough

Agency must take immediate action to cancel weedkiller

WASHINGTON – Today the Environmental Protection Agency publicly warned farmworkers of the “serious, permanent, and irreversible health risks” posed by the pesticide DCPA – in what is likely a final step before the agency bans the toxic weedkiller.

The announcement disappointingly restates what the agency found in a critical health assessment released by the EPA, in May 2023, highlighting the significant risks DCPA poses to humans – particularly to farmworkers and pregnant people. The weedkiller is sold in the U.S. under the brand name Dacthal.

“The EPA’s own conclusions and the overwhelming scientific evidence underscore the ongoing risks of the toxic pesticide DCPA,” said Environmental Working Group Senior Toxicologist Alexis Temkin, Ph.D. “As long as DCPA continues to be legal, the chemical will continue to pose real dangers to farmworkers,  people who are pregnant and other vulnerable populations exposed to it.”

The EPA’s conclusion is based on its analysis of research by AMVAC – the agrochemical giant that is the only manufacturer producing DCPA for the U.S. market – showing that DCPA can harm the developing fetus, even at very low doses. Although the EPA asked for the study in 2013 because of emerging concerns about the threat DCPA poses to human health, AMVAC didn’t submit it until 2022 – nine years later.    

Since 2018, EWG has sounded the alarm about DCPA due to serious concerns about the harm it can cause to exposed people. The organization called for a ban on the herbicide in 2021 public comments to the agency and in official comments submitted to the agency in July 2023

The EPA classified DCPA as a “possible carcinogen” in 1995, and it’s been banned in the European Union since 2009. 

“It’s past time for the EPA to ban DCPA,” said EWG President Ken Cook. “The agency should have taken action to cancel DCPA uses 10 months ago, when it first released these findings, and must now act immediately to protect farmworkers and others from this dangerous weedkiller.”

DCPA can drift from the fields where it is sprayed, and it is regularly detected in dust samples from the homes of farmworkers and those living in farming areas. A 2021 study from a group of researchers found an association between DCPA in dust samples and higher risk of childhood leukemia. 

A 2019 study led by scientists at the University of California at Berkeley School of Public Health found that more than 50 percent of adolescent girls from farmworker communities in the Salinas Valley had been exposed to DCPA. 

A 2022 peer-reviewed study by EWG scientists identified DCPA as a pesticide of concern, due to its toxicity and capacity to harm the thyroid, and its classification as a possible cause of cancer. 

Other EWG research found that, even though the EPA had evidence of DCPA’s health risks, up to 200,000 pounds of the chemical was sprayed during some years in California – even while the agency continued to delay taking action.


The Environmental Working Group is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy and unique education tools, EWG drives consumer choice and civic action. Visit for more information.

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