SAFETY ASSESSMENT OF ENZYME-CONTAINING PERSONAL CLEANSING PRODUCTS - EXPOSURE CHARACTERIZATION AND DEVELOPMENT OF IGE ANTIBODY TO ENZYMES AFTER A 6-MONTH USE TEST

Background: Enzyme-containing personal cleansing products were being c onsidered for the consumer market. Although enzymes have been marketed safely for many years as ingredients in laundry products, their use i n a personal cleansing application represented a new type of exposure for consumers that was not supported by the historical safety data. An exposure assessment and additional safety data would be needed before marketing to ensure consumer safety. Objective: The work in this pape r was designed to evaluate the potential for inhalation exposure to th e enzyme during use of this new product while showering. Then a clinic al trial was conducted to determine whether or not the level, duration , and routes of exposure encountered during use of this product would induce a Type I sensitization response to the enzyme. Methods: Exposur e was assessed during normal showering activities by collecting air sa mples with both high volume and personal samplers and quantitating enz yme levels with an ELISA. To assess the potential for sensitization, p anelists were asked to use a prototype protease-containing bar product for all personal cleansing tasks and to keep a use diary reporting an y associated symptoms. Physical and dermatologic examinations and skin prick tests with enzyme were conducted before the test commenced and at 2-month intervals. Results: Exposure assessment results showed that airborne enzyme levels were primarily dependent on the concentration of the enzyme in the personal cleansing product. Mean values for total airborne enzyme protein ranged from 5.7 to 11.8 ng/m(3) when enzyme c oncentration, time of use, and measurement technique remained constant . After 6 months of at-home product use, four of 61 test subjects usin g the enzyme-containing bar had positive skin prick test responses whe n tested with the enzyme. The skin prick test data were supplemented w ith serologic analyses, which detected IgE specific for the protease e nzyme. None of these subjects showed any clinical symptoms indicative of allergic reaction. Conclusion: The ability of enzymes to induce dev elopment of allergic antibodies in this study led to the conclusion th at this prototype enzyme-containing personal cleansing bar would repre sent an inappropriate use of enzymes in a consumer product application . The likelihood of both induction of an immunologic response and subs equent elicitation of allergy symptoms in a small but significant frac tion of the user population was high. This finding resulted in the dec ision to halt further development of this prototype.