White phosphorus - Matches, phossy jaw, and suicide by firework ingestion

• an artificial allotrope made up of molecules consisting of four atoms of phosphorus
• is actually yellow, which is why it is also called yellow phosphorus (mind boggling)
• is flammable and pyrophoric (self-igniting) when it comes in contact with air, with combustion producing a distinctive garlic smell
• first produced on a commercial scale during the industrial revolution (i.e. 19th century) for use in making matches
• during this time, chronic low-level intoxication was most common, occuring via inhalation of air contaminated with particles of the stuff and via the skin (dermal contact)
• chronic exposure to white phosphorus can cause a characteristic necrosis affecting the bones of the jaw ("phossy jaw"), which was commonly seen in match workers at the time
• matches are now made with red phosphorus, which is less flammable and toxic, and workers wear protective clothing and masks and stuff, so phossy jaw isn't really seen anymore
• currently most cases of intoxication are via self-induced (e.g. life isn't worth living anymore) ingestion of fireworks (!) and certain pesticides (organophosphates)
  
• this remains an important health problem in certain parts of the world as such poisonings are associated with a significant mortality (about 23% to 73% depending largely on the size of the ingested dose)
• following ingestion, concentrates primarily in the liver but also in the brain, striated muscle, and the kidneys where it causes damage to these sites - see liver damage, renal failure, arrhythmias, seizures, coma - death usually due to liver failure or cardiovascular collapse
• may also be toxic to bone marrow
• the poop of people who ingest white phosphorus can give off white smoke if it contains enought phosphorus, this is awesomely referred to as "smoking stool syndrome"

Tafur AJ et al. Bone marrow toxicity after yellow phosphorus ingestion. Emerg Med J. 2004 Mar;21(2):259-60.
http://en.wikipedia.org/wiki/Phosphorus
http://www.emedicine.com/EMERG/topic918.htm