Organophosphates are a class of chemical substances produced by the process of esterification between phosphoric acid and alcohol. They are widely used as herbicides, pesticides, and insecticides, and are also the main components of nerve gas. Organophosphates can undergo hydrolysis with the liberation of alcohol from the ester bond. They can be considered as esters of phosphoric acid. Organophosphates are nerve poisons that act through inhibition of cholinesterase. They can cause varying levels of toxicity in humans, animals, plants, and insects. Exposure to organophosphates can happen through ingestion, inhalation, or dermal absorption. Organophosphates can disrupt the brains and nervous systems of animals and humans by stopping a key enzyme in the nervous system called cholinesterase from working. Symptoms of organophosphate poisoning can include excessive fatigue, poor concentration, and suicidal thoughts. Organophosphates are not likely to build up to high or dangerous levels in animal or plant foods that people might eat.