Osmium Tetroxide - Safety Considerations

Safety Considerations

OsO₄ is highly poisonous, even at low exposure levels, and must be handled with appropriate precautions. In particular, inhalation at concentrations well below those at which a smell can be perceived can lead to pulmonary edema, and subsequent death. Noticeable symptoms can take hours to appear after exposure.

OsO₄ also stains the human cornea, which can lead to blindness if proper safety precautions are not observed. The permissible exposure limit for osmium tetroxide (8 hour time-weighted average) is 2 µg/m3. Osmium tetroxide can penetrate plastics and therefore is stored in glass in a cold place.

On April 6, 2004 British intelligence sources believed they had foiled a plot to detonate a bomb involving OsO₄. Experts interviewed by New Scientist affirmed osmium tetroxide's toxicity, though some highlighted the difficulties of using it in a weapon: osmium tetroxide is very expensive. The osmium tetroxide may be destroyed by the blast; what remaining toxic fumes may also be dispersed by the blast as well.