Yellow/white phosphorus toxicity

There are two naturally occurring types of elemental phosphoms red and yellow. Red phosphorus is not absorbed and is essentially nontoxic, in contrast, yellow phosphorus (also called white phosphorus) is a highly toxic cellular poison. Yei-low/white phosphorus is a colorless or yellow wax-like crystaiiine solid, with a garliclike odor, and is almost insoluble in water. Although no longer a component of matches, yellow/white phosphorus is still used in the manufacture of fireworks and fertilizer and as a rodenticide. 

Elemental sulfur is a yellow solid, in which eight snlfnr atoms form a crown-shaped ring Ss. Unlike elemental white phosphorus, elemental snlfnr has very low toxicity. Years ago, people in the United States took a preparation of snlfnr and molasses as a spring tonic. Taken orally, sulfur has a mild laxative effect. Beyond that, it is not clear to me what favorable effects this tonic may have had, if any. There is a lot of snlfnr aronnd. When taken in all its forms, it accounts for nearly 2% of the weight of the crnst of the Earth. 

Phosphorus is available in two forms, white (or yellow) and red. White phosphorus appears to be molecular, with a formula of P,. It is a waxy solid with a melting point of 44°C, and ignites spontaneously on exposure to air. It must be kept cool and is usually stored under water. It is highly toxic in both the solid and vapor form and causes burns on contact with the skin. Its use in pyrotechnics is limited to incendiary and white smoke compositions. The white smoke consists of the combustion product, primarily phosphoric acid (H 3PO,). 

The most common elemental form of phosphorus, white phosphorus, is highly toxic. White phosphorus (melting point (mp), 44°C boiling point (bp), 280°C) is a colorless waxy solid, sometimes with a yellow tint. It ignites spontaneously in air to yield a dense fog of finely divided, highly deliquescent P4O10 ... 

Phosphorus has many allotropes. The most common of these is white phosphorus, which exists in two modifications, a-P4 (cubic) and p-P4 (hexagonal). Condensation of phosphorus from the gas or liquid phases (both of which contain tetrahedral P4 molecules) gives primarily the a form, which slowly converts to the P form at temperatures above —76.9°C. During slow air oxidation, a-P4 emits a yellow-green light, an example of phosphorescence that has been known since antiquity (and is the source of the name of this element) to slow such oxidation, white phosphorus is commonly stored under water. White phosphorus was once used in matches however, its extremely high toxicity has led to its replacement by other materials, especially P4S3 and red phosphorus, which are much less toxic. 

Phosphorus can be absorbed into the systemic circulation from the skin, lungs, and intestinal tract. For all practical purposes, white and yellow phosphorus are readily absorbed while red phosphorus is not. The target organs of toxicity include the gastrointestinal tract, liver, kidney, bone, and the cardiovascular and central nervous systems. 

---