Phossy jaw is a deadly occupational hazard for those who work with white phosphorus in an environment without proper safeguards. It was most commonly seen in workers in the match industry in the 19th and early 20th century. Modern industrial hygiene practices have eliminated the conditions which lead to this affliction.
Chronic exposure to white phosphorus vapour, the active ingredient of most matches from the 1840s to the 1910s, caused a deposition of phosphorus in the jaw bones. It also caused serious brain damage. Workers afflicted would begin suffering painful toothaches and swelling of the gums. Over time, the jaw bone would begin to abscess, a process which was both extremely painful and disfiguring to the patient, and repellent to others, since drainage from the dying bone tissue was exceedingly foul-smelling. The jawbones would gradually rot away and would actually glow a greenish-white color in the dark. Surgical removal of the afflicted jaw bones might save the sufferers' life at this point—otherwise, death from organ failure would invariably follow.
Public revulsion eventually caused changes in match manufacturing which eliminated the disease. In some nations, legislative action was required to force these changes on a reluctant industry.
A related condition, osteonecrosis of the jaw, has been described as a side-effect of bisphosphonates, a class of phosphorus-based drugs that inhibit bone resorption, and are used widely for treating osteoporosis, bone disease in cancer and some other situations.