Chemicals of low toxicity such as table salt or ethyl alcohol can be fatal if consumed in large amounts. Conversely a highly toxic material may pose no hazard when exposure is minimal. The threat of crop destruction with resultant financial loss is a strong incentive for farmers to observe use instructions on pesticide labels and thus assures that residues will be below established tolerances. Crops grown for export are often checked for residues by foreign residue laboratories to assure that local tolerance limits are not exceeded. This is done by following several safety practices including the use of protective clothing and equipment.
All pesticides are hazardous if misused, no matter what their toxicity.
All pesticides can be handled safely by using safety practices that minimize or eliminate exposure to them. Federal laws regulating pesticides have placed the burden of proving safety of pesticide usage on the manufacturer. Hazard evaluation studies are generally done by scientific laboratories maintained by the manufacturer or through outside contract laboratories. Few products are subjected to such extensive and vigorous testing as pesticides are before they are marketed. Many promising pesticide products are not marketed because they do not pass the extensive toxicology testing.