The toxicity generally results from accidental or intentional ingestion of, or occupational exposure to, agricultural pesticides. Other potential causes of organophosphate or carbamate toxicity include ingestion of contaminated food. Organophosphates and carbamates are the most common classes of chemicals used for the control of insects on vegetables because of their high efficacy and broad spectrum of activity. As a result, the insecticide residues are likely to occur in vegetables. The inappropriate usage of the insecticides increases the risk of human exposure. Therefore, it is important to determine the levels of the insecticides in vegetables to protect human health.