Toxicity of Ozone in High Altitude Flight

Ozone is found at high altitudes in such concentration that, pressurized in a cabin to ground level or near ground level pressure, it could exhibit harmful effects on man and material. Protecting factors, such as heating in the compressor, decomposition in contact with various substances, and use of oxygen masks, lessen such harmful effects considerably. But the existence of such a hazard has to be known. Studies on the toxic effect of ozone on man indicate that such effect is restricted to the respiratory tract. Man seems to be more sensitive than the usual laboratory animals. In sensitive persons, concentrations as low as 2 p.p.m. may cause severe irritation within less than 1 hour.