Paraphenylene diamine leads not unfrequently to industrial poisoning from use of ursol as a dye. It produces skin eruptions and inflammation of the mucous membrane of the respiratory passages.[12] No doubt the intermediate body produced (diimine) acts as a powerful poison.
A case of metaphenylene diamine poisoning is quoted in the Report of the Union of Chemical Industry for 1906. A worker had brought his coffee and bread, contrary to the rules, into the workroom and hidden them under a vessel containing the substance. Immediately after drinking his coffee he was seized with poisoning symptoms, and died a few days later. Some of the poison must have dropped into his coffee.
Few instances of poisoning from pure aniline colours are recorded.
At first all tar colours were looked upon as poisonous, but as they were mostly triphenylmethane colours they would contain arsenious acid. When the arsenic process was given up people fell into the other extreme of regarding not only the triphenylmethane colours but all others as non-poisonous, until experience showed that production and use of some of the tar colours might affect the skin.
Finally, mention must be made of inflammation of the cornea caused by methyl violet dust. The basic aniline dyes are said to damage the eye. As opposed to this view is the fact that methyl violet and auramine are used as anti-bactericidal agents, for treatment of malignant tumours, and especially in ophthalmic practice.