Pesticides Classification and its Impact on Environment

Abstract

Pesticides are substance or mixture of substance which differ in their physical, chemical and identical properties from one to other. Hence, they are classified based on these properties. Some pesticides are also categorized into various classes depending on the needs. Presently, three most popular classifications of pesticides which are widely used is classification based on the mode of entry, pesticide function and the pest organism they kill, the chemical composition of the pesticide. Based on toxicity of pesticides, WHO classified them into four classes: extremely dangerous, highly dangerous, moderately dangerous and slightly dangerous. Improper application of pesticides can cause severe harmful effect to living system and the environment. Most pesticides do not distinguish between pests and other similar incidental lifeform and kill them all. The toxicity of insecticides to an organism is usually expressed in terms of the LD50 (lethal dose 50 percent) and LC50 (50 percent lethal concentration)