Thursday, June 15, 2017

Fake Silk

From Undark:
There could have been no more knowledgeable or better-placed recipient of such an urgent appeal. Alice Hamilton was a leading U.S. authority on the toxicity of carbon disulfide, the compound that appeared to be causing the rayon illnesses. Back in 1915, as a medical expert working with the federal Bureau of Labor Statistics, she had studied its use in the rubber industry — though even then it was falling out of favor, in part because of its well-recognized dangers.

Hamilton had inspected nine rubber factories for the bureau. Of 16 cases of mental illness she tallied, one worker had been briefly committed to an insane asylum and several others had experienced other nervous system complaints. One man had worked for only a month before he began to show signs of derangement: “He was Hungarian and spoke no English, and the foreman did not recognize his condition until he became very much excited and unmanageable. He was sent home, and his wife reported that he acted so strangely and was so uncontrollable that she took him to a doctor. When the latter asked him about his work he told a rambling tale of lumbering down a river, and could not be convinced that he had ever worked in a rubber factory.”

Carbon disulfide was not the only toxic substance Hamilton encountered. Aniline, a compound added to rubber to accelerate the manufacturing process called vulcanization, was of special concern because it poisons the blood, giving it a bluish tinge and causing acute oxygen deprivation. In one rubber plant in Akron, Ohio, the problem was so endemic that its workers were called the “blue boys.”

Then there was thiocarbanilide, a vulcanizing accelerant produced by combining aniline with carbon disulfide in a kind of toxic perfect storm. In 1919, during a visit to a major producer of the compound in Marcus Hook, Pennsylvania, Hamilton noted symptoms that suggested both aniline and carbon disulfide poisoning: “They have had a man suffer from intense headache and nervousness so that he could not sleep.”

Now, in 1933, carbon disulfide seemed to be wreaking havoc among workers in the relatively new industry that was transforming plant fiber into the wildly popular artificial silk called viscose rayon. And while rubber making could use other chemicals in the vulcanization process, viscose rayon absolutely depended on carbon disulfide. (Read more.)

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