Ocular Injury Due to Sulfur Dioxide

THE ACCIDENTAL injuries of the eye produced by liquefied sulfur dioxide which have been reported by myself 1 and others have usually been severer than those produced by other substances with similar moderately acidic properties. To account for the greater toxicity of sulfur dioxide, previous observers have proposed some rather unusual mechanisms based on the physical and chemical peculiarities of the noxious agent. Experiments carried out in this laboratory indicate that a relatively simple mechanism, different from those previously proposed, is responsible in large measure for the peculiar toxicity of sulfur dioxide. The following two hypotheses have previously been advanced to explain the severity of ocular injury produced by liquid sulfur dioxide. It has been assumed by some investigators that injury of the eye is due to freezing produced by the rapid evaporation of the liquefied gas (Kennon, 2 Clark 3 ), while others have assumed that injury is caused by