Skin risk assessment of metalworking fluids: a survey among Swiss suppliers.

BACKGROUND Metalworking fluids (MWF) are the most important cause of hand dermatitis in the metal industry. The substitution of noxious products by less aggressive MWFs is therefore an important measure to reduce the incidence of hand eczema in this type of industry. In order to do so, producers and suppliers have to evaluate the skin risk of such products by predictive allergenicity and irritancy testing. OBJECTIVE The aim of the study is to evaluate if predictive testing is performed in MWF products that are currently offered in the Swiss market and what kind of tests are applied. METHODS A questionnaire was sent to 11 Swiss MWF suppliers in order to collect information on the actual practice of skin risk testing. RESULTS Nine of 11 suppliers returned the questionnaire. Five suppliers report some kind of allergenicity testing in some of the products. Seven companies test for irritancy by a single application method, but only two perform cumulative irritancy testing in some products. The methods of testing (animal, human, field studies) vary greatly among the different companies. CONCLUSION It is concluded that the practice of predictive testing for sensitization and irritancy of MWF is unsatisfactory and does not allow the user to compare products based on their skin risk. Occupational dermatologists should strive for standardization of MWF testing including so far scarcely performed repeated insult tests.