The administration of US president Donald Trump appears eager to clear the way for the continued sale of the controversial pesticide chlorpyrifos.

The Justice Department last week filed an appeal on behalf of the Environmental Protection Agency (EPA), asking the San Francisco-based US 9th Circuit Court of Appeals to allow a full panel of 22 judges to reconsider the court’s earlier reinstatement of a ban on the chemical.

One of the first moves of the Trump-era EPA under since-ousted administrator Scott Pruitt, in March 2017, was to overturn an Obama administration ban of the pesticide that has been linked to developmental disorders in children whose mothers were exposed to it during pregnancy.

The appeals court reinstated the ban in August 2018, saying that in overturning it the Pruitt  EPA had violated the Federal Food, Drug, and Cosmetic Act and the Federal Insecticide, Fungicide and Rodenticide Act. Both require the agency to ban a crop protection product from use on food unless there is reasonable certainty that it will cause no harm.

“The EPA has never made any such determination and, indeed, has itself long questioned the safety of permitting chlorpyrifos to be used within the allowed tolerances,” the court said. Officially, the agency is reviewing the substance up to 2022.

If the appellate judges refuse to reverse their decision, the Trump administration’s last-ditch option would be to seek the help of the Supreme Court to keep chlorpyrifos on the market.

The most widely used pesticide in agriculture is licensed for more than 60 crops, including grapes, citrus fruit, almonds, walnuts, alfalfa and cotton. One of its major dangers is that it can attack the nervous system.

The original ban, enacted in November 2015, was the result of lawsuits brought by environmental NGOs. More recently, California’s Department of Pesticide Regulation proposed listing chlorpyrifos as a toxic air contaminant, which would bring tighter rules on its use in the state.