Chlorpyrifos is a chemical used by extensively by conventional apple growers in Washington State. The EPA has been very slowly getting around to banning its use completely. The EPA’s slowness to rule on Chlorpyrifos commercially is an entirely different topic; a great source of frustration for many. Great article on that here.
We all know that big chemical companies have a lot at stake, and that political lobbyists get paid to fight for the big-corporate bottom line, and that our political processes are bogged down by bureaucracy. It sucks.