Two important allotropes of elemental phosphorus are white phosphorus and red phosphorus:
A. why should gloves be worn when handling white phosphorus?
B. Why are firefighters advised to use dry sand rather than wet sand to extinguish a small red phosphorus fire?
White phosphorus and red phosphorus are the two most important allotropes of elemental phosphorus. White phosphorus, which is also sometimes called yellow phosphorus, is the unstable form of elemental phosphorus at room conditions (Meyer, 2010). Red phosphorus on the other hand, also known as amorphous phosphorus, is produced industrially. This allotrope is produced by heating white phosphorus, which has to be at a temperature of 482 °F, in an iron container from which air has been excluded (Meyer, 2010). Unlike white phosphorus, which is highly poisonous and spontaneously combustible, red phosphorus is less chemically reactive and neither spontaneously combustible nor poisonous in small quantities. The storage of bulk quantities of red phosphorus are highly unlikely to be encountered for this reason, but because red phosphorus does burn when exposed to an ignition source. There have been instances where small quantities of this allotrope have been involved in fires (Meyer, 2010). Red phosphorus, when ignited, produces the toxic gas phosphine. Phosphine cannot be extinguished with the use of wet sand, therefore when extinguishing a red phosphorus fire, dry sand, foam, or other dry chemicals must be used (Meyer, 2010). There are also many hazards associated with white phosphorus. Although the principal hazard associated with this allotrope is spontaneous combustion, white phosphorus can also be highly poisonous in vapor form and a hazard to the skin if not handled correctly. If white phosphorus is handled without the use of gloves, it can cause severe burning to the skin and produce extremely painful wounds that are very slow to heal (Meyer, 2010).