THE HAZARD OF TOXIC GASES FROM COMBUSTION OF ROENTGEN-RAY FILMS

When the first newspaper reports of the Cleveland catastrophe were issued, the toxic effects were attributed to what were described as heavy brown fumes of bromine gas and to various other toxic gases. To chemists familiar with the decomposition of nitrocellulose, it seemed certain that the brown fumes were those of nitrogen tetroxide. The inflammable type of film is prepared from nitrocellulose, or nitrated cellulose, as it is frequently called; the substance is one quite familiar to those who have studied explosives and the effects of their gaseous by-products. When the product is subjected to combustion—or "explosion"— there are produced among other substances carbon monoxide and nitric oxide (NO). Nitric oxide, even in air, quickly takes on oxygen, forming nitrogen dioxide (NO₂) or its polymer nitrogen tetroxide (N₂O₄)—the form in which it exists depending on the temperature. All students in first year chemistry recall the