Concerns that the insecticide can harm the brain and nervous system led to the EPA banning the household use of chlorpyrifos in 2000. But the agency had allowed the chemical to continue tobe used in commercial agriculture, where, some scientists say, it can be used in safe quantities.
"EPA is reviewing the decision," spokesman Michael Abboud said in a statement on Thursday. He wrote that the data behind a Columbia University scientific study considered by the Obama administration and the court during their reviews of the pesticide "remains inaccessible" to the agency.
The EPA and the courts have considered an outright ban on the chemical since 2007, when public health groups petitioned the agency, and in August 2015, the 9th US Circuit Court of Appeals ordered the EPA to make a decision.
The Trump administration-led EPA made that decision in April 2017, when it ruled that a broader ban on the chemical was not warranted, citing "uncertainty" in the science linking chlorpyrifos to "neurodevelopmental effects." The administration said it would continue to review the science and make its next determination on the chemical's safety in 2022, as required by law.
The ruling, also by the 9th Circuit, overturns that decision.The court blasted the agency -- under both Democratic and Republican leadership -- for having "stalled on banning chlorpyrifos."
"If Congress's statutory mandates are to mean anything, the time has come to put a stop to this patent evasion," the opinion reads.
Internal EPA emails released last summer appeared to show politics played a role in the administration's 2017 decision. While the decision was under consideration, then-EPA administrator Scott Pruitt told chemical industry representatives in a meeting that "this is a new day, a new future, for a common sense approach to environmental protection,"
according to notes circulated among his staff. Another Trump administration appointee, Don Benton, said the agency was building "new relationships" with the industry "based on partnerships not on regulations and enforcement."
The agency's chief of staff, a political appointee, had suggested in an email that career scientists wanted the pesticide banned.
"I scared them Friday," Ryan Jackson wrote to a colleague. He wrote in a follow-up email that he had been joking when he suggested the career employees "are trying to strong arm us." But, he wrote, the career staffers "know where this is headed and they are documenting it well."
When the notes were released publicly because of a Freedom of Information Act request, the agency argued they had been taken "out of context," and noted that the review continues.