The authors describe three accidental deaths resulting from occupational hazards involving
environmental gas alterations. One involved the displacement of oxygen caused by leakage
of liquid nitrogen during the installation of a magnetic resonance imaging system. Two
involved elevated environmental carbon dioxide concentrations: dry ice sublimation in a
walk-in refrigerator in a research laboratory, and activation of a carbon dioxide fire alarm-
extinguisher system by a woman locked in a bank vault. The autopsy findings, scene …