SALEM — Oregon Attorney General Ellen Rosenblum is joining a lawsuit against the U.S. Environmental Protection Agency challenging the use of chlorpyrifos, a widely used pesticide, on food crops.

The case was filed Aug. 7 in the 9th U.S. Circuit Court of Appeals by the state attorneys general of New York, California, Washington, Massachusetts, Maryland and Vermont, arguing chlorpyrifos is a toxic chemical that can harm infant and child neurological development.

Environmental groups including the Pesticide Action Network North America and Natural Resources Defense Council originally petitioned the EPA to ban chlorpyrifos in 2007. Former EPA Administrator Scott Pruitt denied the petition in 2017.

A dozen groups fought the decision to the appeals court, which ordered the EPA to reconsider prohibiting the insecticide. The agency, now led by Andrew Wheeler, upheld its decision in July, allowing farmers to continue using chlorpyrifos.

Rosenblum said it is “really alarming that the Trump administration is disregarding the law by allowing a toxic pesticide that is dangerous to young children and infants to be used in our national food stream.”

“Every one of us eats food that comes from around the country, so until the EPA can show this pesticide is safe, there should be a national ban,” Rosenblum said. “Farmworkers, their families and children living nearby are the people to bear the disproportional brunt of this toxin.”

As of 2016, between 5 million and 7.5 million pounds of chlorpyrifos were applied to food crops annually across the country, according to the states’ lawsuit. Rosenblum said the EPA’s own scientists have twice been unable to identify a safe level for the pesticide on food.

The EPA under the Obama administration did consider a rule to ban chlorpyrifos in 2015, but Pruitt later reversed course, citing “serious scientific concerns and substantive process gaps in the proposal” in his denial. The agency plans to complete a review of the chemical by Oct. 1, 2022.

Chlorpyrifos was patented in 1966, and remains one of the most widely used pesticides in the U.S. It is registered for about 50 crops in Oregon, including seed production crops, vegetable crops, Christmas trees and nursery plants.

Earlier this year, the Oregon Legislature considered bills that would ban chlorpyrifos. House Bill 3058 and Senate Bill 853 died in committee.

Katie Fast, executive director of Oregonians for Food and Shelter, an agribusiness group that advocates safe use of pesticides and biotechnology, said chlorpyrifos is an important tool for farmers to fight pests like aphids and roundworms.

While some growers of tree fruits and specialty crops have been able to phase out chlorpyrifos, Fast said others do not have registered alternatives. Without chlorpyrifos, she said they could see significant pest damage.

Fast said she sees the states’ lawsuit as more politically driven than science-based. One notable epidemiology study conducted by the Columbia Center for Children’s Environmental Health, which the EPA relied upon in its proposed ban of chlorpyrifos in 2015, has not been reproduced and raw data was not made available to the agency, Fast said.

“The labeling process for pesticides through the EPA is very science-based, and takes into account all environmental and human health exposure that could happen through application or food consumption,” Fast said.

Lisa Arkin, executive director of Beyond Toxics, an environmental and human health organization based in Eugene, Ore., said chlorpyrifos is shown to damage nerve cells and have long-term effects on brain development in children.

It is also hazardous to other insects and wildlife such as bees and fowl, Arkin said.

Banning the chemical was top legislative priority for the Oregon Conservation Network this year, and Arkin said she was pleased to see Rosenblum recognize the hazards posed by chlorpyrifos.

”The level of awareness was raised significantly (in the Legislature),” Arkin said. “We’re glad the attorney general has included this in the list of her top concerns.”