NEW YORK (Reuters) - Six state prosecutors are seeking to join a lawsuit to force the U.S. Environmental Protection Agency to ban the pesticide chlorpyrifos from use on U.S.-grown fruits and vegetables, according to court papers filed on Thursday.

Democratic attorneys general for New York, Maryland, Vermont, Washington, Massachusetts and the District of Columbia filed a motion to intervene in a case environmental and social advocacy groups brought in a federal appeals court on June 5. It challenges EPA Administrator Scott Pruitt’s March 29 decision not to ban chlorpyrifos from U.S. foods.

The action by the prosecutors adds momentum to a push by environmental groups to broadly oppose Pruitt and U.S. President Donald Trump in their stated aim to loosen U.S. environmental regulations.

“It is EPA’s responsibility to protect Americans from unsafe chlorpyrifos residues on food because of the potential neurodevelopmental and other adverse health effects caused by exposure,” the prosecutors wrote in their filing. “Citizens of the proposed state intervenors consume foods grown throughout the United States and the world that contain chlorpyrifos residues.”

The EPA has previously said chlorpyrifos, which is sold under a range of brand names, did not meet safety standards laid out by a 1938 U.S. law, the Federal Food, Drug and Cosmetic Act. An EPA spokesman declined to comment on Thursday’s filing.

The prosecutors’ move is the latest in a series of administrative and courtroom actions against the pesticide that began long before Trump took office.

In 2007, environmental groups petitioned the EPA to revoke its tolerance of chlorpyrifos residues on food. Over the next nine years, the groups obtained a series of court decisions forcing action by the EPA, which said in 2015 it was “unable to conclude that the risk from aggregate exposure” to the pesticide was safe. Environmental groups have argued humans are exposed to harmful elements in chlorpyrifos not only by eating food containing residues of the pesticide, but also by drinking water contaminated by it.

The EPA issued two proposals to ban chlorpyrifos but never produced a final rule, despite being ordered by a court on two separate occasions to take final action on the matter. Pruitt’s March administrative order reversed the agency’s moves to ban the pesticide, denying the 2007 petition for the ban.

The case is League of United Latin American Citizens v. Scott Pruitt, U.S. Court of Appeals, Ninth Circuit, 17-71636.