Diazinon

Diazinon is an organophosphate insecticide that has been widely used in agriculture and in residential settings to control a broad range of pests on fruit, vegetables, ornamentals, and turf. Its chemical formula is C12H21N2O3P. It acts as a contact and stomach poison for insects and has been valued for its effectiveness against aphids, beetles, caterpillars, and other pests.

Mechanism and toxicity: Diazinon inhibits acetylcholinesterase, an enzyme essential for proper nerve function. Insects succumb to overstimulation of the nervous system, but the compound can also affect mammals, including humans, with exposure. Acute exposure can cause headaches, dizziness, sweating, excessive salivation, muscle twitching, or respiratory problems; severe cases may be life-threatening. It is highly toxic to birds and aquatic organisms and poses concerns for non-target wildlife and bees. Because of its toxicity, safety precautions and proper handling are required.

Usage and regulatory status: Due to health and environmental concerns, diazinon use has been restricted or banned in many regions. In the United States, the Environmental Protection Agency canceled most residential uses in the early 2000s, and agricultural uses are subject to strict labeling. Many countries in the European Union and elsewhere have restricted or withdrawn diazinon from sale for consumer and agricultural use. Regulatory status continues to vary by jurisdiction and product formulation.

Environmental fate: Diazinon degrades in soil and water through hydrolysis and microbial action, with persistence depending on environmental conditions and formulation. It can contaminate water bodies through runoff and drift, and residues may remain on treated crops if harvesting intervals are not observed.