Several states sued the Environmental Protection Agency (EPA) on Wednesday over the agencys decision to allow further use of a pesticide linked to brain damage. California, New York, Massachusetts, Washington, Maryland and Vermont argued in court documents that chlorpyrifos, a common pesticide, should be banned due to the dangers associated with it.

Earthjustice filed a similar lawsuit in the 9th Circuit Court of Appeals on behalf of groups advocating for environmentalists, farmworkers and people with learning disabilities.

“A chlorpyrifos ban is long overdue given the overwhelming evidence that says this pesticide harms brain development in children,” Tracy Gregoire, a project coordinator at the Learning Disabilities Association of America, said in a statement. “We are hopeful the courts will side with children who are now being exposed to irreparable, yet preventable harm.”

Chlorpyrifos, known on the market as Lorsban, is used on a wide variety of crops, including corn and cranberries. Farmers have called it the last line of defense against certain insects. But it has also been linked to learning and memory issues and prolonged nerve and muscle stimulation.

The EPA banned chlorpyrifos for household use in 2001 over concerns it would cause brain damage in children. EPA’s decision to allow continued use of chlorpyrifos came last month, the result of a court-ordered deadline to regulate the pesticide prompted by a lawsuit previously filed by Earthjustice.

EPA would not comment on the lawsuit but said those challenging the use of chlorpyrifos did not have enough data to demonstrate the product is not safe. The EPA said it would continue to review the safety of chlorpyrifos through 2022.

A month after former EPA Administrator Scott Pruitt began leading the department, the agency rejected an Obama-era recommendation from agency scientists to ban the pesticide. In the absence of EPA action, some states have moved to regulate chlorpyrifos on their own. Hawaii last year banned its use, and California and New York are considering a similar move.