The practice of various chemicals to control and eradicate pests and weeds is an important aspect of agricultural sciences. it increases crop yield and reduced post-harvest losses. Mostly, Pesticides are target oriented and do not move from the site of application, but few stay in system for quite some time period, and then enter in the food chain. The extensive use of such pesticides, results in residues in food, which has led to widespread concern over the potential adverse effects of these chemicals to human health. Pesticides used in agriculture generally include insecticides, fungicides,herbicides, etc. Some of the insecticides are applied directly to the crops while, some may still be present as residues in vegetables and fruits even after their harvest. It is true that insecticides are toxic substances, but when used properly they constitute an important input in vegetable and fruit production in order to produce economically marketable products. The pesticides must thus be applied following good agricultural practices (GAP) in order to minimize the impact on health and environment.