From the Greek word for light bearing, phosphoros .
White phosphorus is poisonous and can spontaneously ignite when it comes in contact with air.
For this reason, white phosphorus must be stored under water and is usually used to produce phosphorus compounds. Red phosphorus is not poisonous and is not as dangerous as white phosphorus, although frictional heating is enough to change it back to white phosphorus. Red phosphorus is used in safety matches, fireworks, smoke bombs and pesticides. Black phosphorus is also formed by heating white phosphorus, but a mercury catalyst and a seed crystal of black phosphorus are required. Black phosphorus is the least reactive form of phosphorus and has no significant commercial uses.