Aluminum in the lung: the pyropowder conundrum.

Pulmonary aluminosis is a disease first seen in Germany between 1938 and 1945 which then reappeared in the United Kingdom between 1952 and 1959. All cases were associated with exposure to a submicron-sized aluminum pyrotechnic flake which was lubricated with a non-polar aliphatic oil. Ordinarily, stearic acid, which chemically combines with aluminum to form aluminum stearate, was used as a lubricant to retard surface oxidation during milling of such flake. This new aliphatic lubricant, which simply physically coated the flakes to prevent elemental aluminum oxidation, could be easily washed off of such flakes. In the intracellular milieu, removal of such surface oil permits exposure of oxygen to elemental aluminum; this results in a vigorous exothermic reaction and the potential for tissue damage. It appears that cases occurred only where this oily lubricant was used to manufacture near submicron-sized pyrotechnic flake (ie, United Kingdom, Germany, Sweden), but never where similar flake has been manufactured for almost a century using polar lubricants.