EPA Downgrades Severity of Cancer-Causing Pesticide

Published Feb 15, 2022

What happened: In February 2020, senior officials from the Environmental Protection Agency (EPA) omitted key scientific information from an assessment study examining the health risks of a cancer-causing pesticide. Because of these actions, the pesticide, known as Telone, was determined by the agency to be less likely to cause cancer than previous EPA assessments had determined.

Why it matters: Senior EPA officials interfered with a scientific study examining the potential health risks of a pesticide, thereby undermining the scientific processes meant to keep the public safe from potentially dangerous pesticides. By downplaying the severity of Telone exposure, officials endangered the public, especially agricultural communities that often consist of Latinx, immigrant, and low-income populations.


Under the Trump administration, senior officials at the Environmental Protection Agency (EPA) omitted information from a human health risk assessment examining the health risks of the pesticide 1,3-dichloropropene, also referred to by its brand name “Telone.” The EPA allowed the pesticide manufacturer to label Telone as a “probable carcinogen,” e.g., a pesticide that can probably cause cancer in people, versus a stricter label of “likely or known carcinogen” that would have required far more safety regulations and limitations for use.

The public first learned about these actions when the Public Employees for Environmental Responsibility (PEER) submitted a complaint in 2021 to the EPA’s Office of Pesticide Programs. PEER detailed how the agency failed “to use the best scientific information in decision-making” when it downgraded Telone’s cancer classification from “likely to be carcinogenic to humans” to “suggestive evidence of carcinogenic potential.”

EPA officials interfered by requiring the exclusion of certain scientific evidence related to Telone’s potential health harms. When conducting a review of academic literature, studies containing the full chemical name of the pesticide, 1,3-dichloropropene, were excluded from the search. Only the terms 1,3-D and Telone were included. This resulted in only examining eight studies, while 100 relevant health studies that used the full chemical name were excluded from the review.

Telone is a colorless liquid that is commonly used in agriculture as a pesticide to kill nematodes, insects, and weeds in soils before crops are planted. Acute human exposure to Telone can cause respiratory problems such as coughing, difficulty breathing, and lung irritation upon inhalation. This is supported by research studies showing that inhaling 1,3-dichloropropene for short periods of time can induce acute tissue injury to the lungs and other organs. Chronic exposure over long periods of time can result in severe skin damage and increased cancer risks.

California Attorney General Xavier Becerra also expressed concerns with the EPA’s actions in downgrading Telone’s cancer risk. Becerra organized a coalition of eight attorneys general who filed a comment letter stating that this action would have a disproportionate impact on agricultural communities. The letter stated that agricultural communities “have high rates of adverse health conditions” and therefore “face significant socioeconomic challenges which make them more vulnerable to this disproportionate pollution exposure.”

This is not the first incidence of a chemical risk assessment that was undermined by the Trump administration. A similar incident occurred in 2019 when political officials disregarded findings by EPA scientists that linked trichloroethylene, another cancer-causing chemical, to heart defects in fetuses.

The EPA under the Trump administration disregarded scientific evidence that would have provided a clearer picture of the potential health risks, particularly the cancer risks, from exposure to the pesticide Telone. The EPA’s mission is “to protect human health and the environment,” including from potentially dangerous environmental hazards. By undermining a scientific study that would have highlighted potential health risks, EPA officials placed other considerations before the health and safety of the public, particularly communities of color and low-income communities situated near agricultural operations. By undermining the scientific process meant to protect communities across the United States, the EPA may have endangered the health and safety of thousands of people.