Commonly known as rice tablet or wheat pill, AlP (CAS: 20859-73-8) is a dark gray or yellow inorganic crystalline compound with garlic, fish, or raw liver odor, available as a tablet or pellet bag (15). Although it is stable when dry, in contact with moisture it is hydrolyzed to phosphine (PH₃, hydrogen phosphide, phosphorus trihydride), a highly toxic gas.