WASHINGTON — Several states are seeking to join a legal challenge to a Trump administration decision to keep a widely used pesticide on the market despite studies showing it can harm children’s brains.

Led by New York, the coalition filed a motion Wednesday to intervene in a legal fight over the continued spraying of chlorpyrifos on food.

Massachusetts, Maryland, Vermont, Washington, and the District of Columbia are also seeking to join the suit pending before the U.S. Court of Appeals for the Ninth Circuit in San Francisco.

The states claim that Environmental Protection Agency chief Scott Pruitt violated the law by ending his agency’s effort to ban the pesticide sold by Dow Chemical after federal scientists concluded it can interfere with the brain development of fetuses and infants. Federal law requires the EPA to ensure that pesticides used on food in the United States are safe for human consumption – especially by children, who studies show are typically far more sensitive to negative effects from pesticides.

“Job No. 1 for the EPA should be protecting Americans’ well-being, especially that of our children,” Eric Schneiderman, the attorney general of New York, said in announcing the legal action. “Yet the administration is jeopardizing our kids’ health, allowing the use of a toxic pesticide for which it can’t even identify a safe level.”

Pruitt told Congress last month his decision was based on “meaningful data and meaningful science.” Despite repeated requests, the EPA has thus far not provided copies of any scientific studies Pruitt consulted in determining the pesticide is safe.

Public-health advocates have been pushing for years to ban chlorpyrifos, which is commonly sprayed on citrus fruits, apples, cherries and other crops. Lawyers for Dow and the makers of two other organophosphate pesticides also asked the Trump administration “to set aside” the results of government studies showing they pose a risk to nearly every federally protected endangered species.

Last month, the American Academy of Pediatrics also urged the EPA to ban chlorpyrifos. The group representing more than 66,000 pediatricians and pediatric surgeons said it is “deeply alarmed” by Pruitt’s decision to allow the pesticide’s continued use.

In the past Dow, which sells chlorpyrifos through its subsidiary Dow AgroSciences, has said it helps American farmers feed the world “with full respect for human health and the environment.”

Spending more than $13.6 million on lobbying in 2016, Dow has long wielded substantial political power in Washington. Dow CEO Andrew Liveris is a close adviser to President Trump and the company gave $1 million for Trump’s inaugural activities.

Similar to a chemical spray developed as a weapon prior to World War II, Dow has been selling chlorpyrifos for use on farms since the 1960s. It is now among the most widely used agricultural pesticides in the United States, with about 5 million pounds sold domestically each year.