Aluminium phosphide, with the chemical formula AlP, is a chemical compound composed of aluminium (Al) and phosphorus (P). It is a highly toxic and reactive solid that is commonly used as a fumigant to control pests and insects in stored grains and other agricultural products.

Aluminium phosphide is typically encountered in the form of grayish or dark gray pellets or tablets, which release toxic phosphine gas (PH3) when exposed to moisture or acids. Phosphine gas is highly toxic and can be lethal to humans and animals even at low concentrations.

Some key points about aluminium phosphide include:

1. Fumigant: Aluminium phosphide is widely used as a fumigant to protect stored grains, seeds, and other agricultural commodities from pest infestations. When exposed to moisture in the environment or the natural moisture content of the stored products, the tablets or pellets release phosphine gas, which is highly toxic to insects and rodents.
2. Safety Concerns: Due to its high toxicity, aluminium phosphide poses serious health risks to humans and animals. It must be handled with extreme caution, and proper safety measures and protective equipment are essential when using or handling this compound.
3. Restricted Use: The use of aluminium phosphide is often regulated and restricted to licensed professionals to ensure proper application and to minimize the risk of accidental exposure to toxic gases.
4. Detection and Monitoring: Specialized equipment is used to detect phosphine gas levels during fumigation to ensure that concentrations remain within safe limits.
5. Decomposition Products: When aluminium phosphide reacts with water or moisture, it produces phosphine gas and aluminum hydroxide (Al(OH)3).

Aluminium phosphide is a potent and hazardous pesticide used in agricultural settings to protect stored products from pest infestations. Due to its toxic nature, it must be handled with extreme care, and strict safety guidelines must be followed during its application to prevent accidental exposure and harm to humans, animals, and the environment.