Diazinon (IUPAC name: O,O-Diethyl O-[4-methyl-6-(propan-2-yl)pyrimidin-2-yl] phosphorothioate, INN - Dimpylate), a colorless to dark brown liquid, is a thiophosphoric acid ester developed in 1952 by Ciba-Geigy, a Swiss chemical company (later Novartis and then Syngenta).

A bait form was used to control scavenger wasps in the western U.S. Diazinon is used in flea collars for domestic pets in Australia and New Zealand.

The negative health effects when in contact with Diazinon includes eye watering, drool or runny nose, not having any appetite, throwing up, intense coughing, abdominal pain, or even stiffness in various muscles/paralysis.

In 1939, the chemist Paul Hermann Müller from the then-independent Geigy company had discovered that DDT was effective against malaria-bearing insects.

[citation needed] However, as the decades following the award passed, DDT was found to be such an environmental danger that developed countries and eventually world-level organizations banned the insecticide for all purposes except for combating disease-vector insects, leading Ciba-Geigy to research alternatives.

Insects lack this hydrolysis step, which allows the toxic substance to accumulate rapidly; the detoxification of diazoxon is processed through the microsomal mixed function oxidase system.

[citation needed] To date, several methods such as electrochemistry, adsorption, enzymatic biodegradation, and photocatalysis have been tested for the elimination of diazinon from aqueous solutions.

The removal of organophosphates (OPE) from water by adsorption techniques is regarded as one of the competitive methods because of its simple operation and low cost.

These states which continue to use Diazinon is their products consider its risks low, yet its greatest effect is through inhalation and skin contact.

Intoxication of diazinon produces the following signs and symptoms: Typically treatments will vary depending on exposure and method of administration of the toxin.

Diazinon, although a thiophosphoric ester, shares a common mechanism of toxicity with other organophosphate insecticides such as chlorpyrifos, malathion and parathion, and is not very effective against the organophosphate-resistant insect populations.

The symptoms can progress to vomiting, abdominal cramps, diarrhea, muscle twitching, weakness, tremor, a lack of coordination and miosis.

Intermediate syndrome in humans is characterized by difficulty breathing and muscular weakness, often in the face, neck and proximal limb muscles.

[citation needed] A study found that 10% of 21 typically developing children show 2-isopropyl-6-methyl-4-pyrimidinol (IMPy, a metabolite of diazinon) in molars.