A little history lesson. Since it was first registered by the Environmental Protection Agency in 1965 to control pests in both commercial and non-commercial agricultural settings, chlorpyrifos has had a checkered past. Chlorpyrifos has long been a go-to pesticide for the U.S. corn producers. But by 2000, it was becoming widely recognized that misuse of the pesticide had unintended consequences – killing fish and wildlife and potentially endangering human health. Instead of immediately banning use of chlorpyrifos, the EPA tried a voluntary approach, requiring chlorpyrifos users to promise pretty please to not use the pesticide around the house (except as roach and ant bait that had to be sold in child-proof packaging) and discontinue use on tomatoes, apples after blooming and lowering how much could be sprayed on grapes.