Acute toxicity of the combustion products from various kinds of fibers.

Acute toxicity of the combustion products from various fibers was evaluated in animal experiments. The materials used were cotton, gauze, acetate, rayon, polyester (PE), polychlal (PC), polyvinylidene chloride (PVDC), silk, wool, polyacrylonitrile (PAN), and modacryle (MA). Rats, mice, and rabbits were exposed to gases released from these materials, heated with an electric heater. In experiments with rabbits animals inhaled gases through a tracheal cannula under urethane narcosis. As indices for toxicity, the time at which animals were impaired severely, was used in rat experiments while the death time was used in experiments with rabbits and mice. The concentrations of O2 and CO in the exposure room were determined continously, blood COHb and cyanide values were also estimated. Gases from fibers containing nitrogen impaired severely and killed the animals earlier than any other materials. Blood analyses revealed the presence of high values of cyanide in PAN, MA, and silk experiments. HCN was considered to be responsible for the high toxicity of gases from these materials. In the case of wool, despite of high toxicity of its combustion products, blood cyanide and COHb values were not very high. Gases from cotton, gauze, and rayon impaired severely and killed the animals relatively early in the exposure period. Toxicity of combution products from these materials was attributable to CO on the basis of gas and blood analyses. Acute toxicity of PE and acetate gases, being less than that of cotton, gauze, rayon under the present experimental conditions, was explained mainly by CO. Neither severe impairment nor death occurred during exposure in PC and PVDC experiments.