Under a 2014 legal agreement, the National Marine Fisheries Service is required to issue findings on the use of the three pesticides under review — chlorpyrifos, diazinon and malathion — by the end of this year. The Environmental Protection Agency, which is also involved in the case, is responsible for determining whether pesticides sold in the United States are safe for people and wildlife.
The Associated Press first reported in April that lawyers representing Dow and the other companies sent letters to three of Trump's Cabinet secretaries claiming the government's studies were fundamentally flawed. Dow wrote a $1 million check to help underwrite Trump's inaugural festivities, and company CEO Andrew Liveris led a now-disbanded White House manufacturing working group.
It is the latest example of the Trump administration seeking to block or delay environmental rules at the behest of the industry. EPA Administrator Scott Pruitt in March reversed an Obama-era effort to bar spraying chlorpyrifos on fruits and vegetables after peer-reviewed studies found that even tiny levels of exposure could hinder the development of children's brains.
Government scientists also compiled an official record running more than 10,000 pages indicating the three organophosphates pose a risk to nearly every endangered species they studied. Before the change in administration, federal regulators had been expected to issue new limits on how and where the three pesticides can be used.
Organophosphorus gas was originally developed as a chemical weapon before World War II. Dow, based in Midland, Michigan, has been selling chlorpyrifos for spraying on citrus fruits, apples, cherries and other crops since the 1960s. It is among the most widely used agricultural pesticides in the United States, with Dow selling about 5 million pounds (2.3 million kilograms) domestically each year.
A coalition of environmental groups has fought in court for years to spur the federal government to more closely examine the risk posed to humans and endangered species by pesticides, especially organophosphates.
"It's appallingly clear that the pesticide industry is now essentially running Trump's EPA," said Lori Ann Burd, environmental health director at the Center for Biological Diversity. "Rather than following the science and the law, the agency is turning its back on endangered species across the country."
Follow AP Environmental Writer Michael Biesecker at http://twitter.com/mbieseck