Patch testing of coolant fractions.

Dermatitis among machine operators, and others who are consistently exposed to cutting and grinding liquids, has presented the industrial physician with the problems of how to protect the machinist from the cause of his dermatitis and how to detect irritants that may be responsible for the skin problem. In order to examine the various components of machine coolant that might be responsible for causing a dermatitis reaction, 13 suspensions were prepared. They consisted of various combinations of New Codol¿ (coolant base), biocides, masking agent, tramp oil, used coolant and metal fragments. Patch test techniques were used to examine these suspensions for their potential to cause a localized skin irritation on plant employees. Two hundred and six New Process Gear employees were tested over a ten-month period. The participants were management, general salaried employees and hourly labor employees. There was not a single positive reaction in any one of the 206 individuals who completed their skin testing. Of the 206 tested, 29 persons were tested and retested a total of 62 times over a period of one to 25 weeks after the initial testing. In neither the testing nor the retesting was a positive patch test reaction -- irritant or allergic -- obtained.