Based on 2006 EPA rules, chlorpyrifos has a tolerance of 0.1 part per million (ppm) residue on all food items unless a different tolerance has been set for that item or chlorpyrifos is not registered for use on that crop. EPA set approximately 112 tolerances pertaining to food products and supplies. In 2006, to reduce childhood exposure, the EPA amended its chlorpyrifos tolerance on apples, grapes and tomatoes, reducing the grape and apple tolerances to 0.01 ppm and eliminating the tolerance on tomatoes. Chlorpyrifos is not allowed on crops such as spinach, squash, carrots, and tomatoes; any chlorpyrifos residue on these crops normally represents chlorpyrifos misuse or spray drift.