Calcium phosphide (CP, Ca3P2) is a chemical used in incendiary bombs. It has the appearance of red-brown crystalline powder or grey lumps, with melting point of 1600 °C. Its trade name is Photophor for the incendiary use or Polytanol for the use as rodenticide.
It may be formed by reaction of the elements. Metal phosphides have been used as rodenticides. A mixture of food and calcium phosphide is left where the rodents can eat it. The acid in the digestive system of the rodent reacts with the phosphide to generate the toxic gas phosphine. This method of vermin control has possible use in places where rodents immune to many of the common poisons have appeared. Other pesticides similar to calcium phosphide are zinc phosphide and aluminium phosphide.