Enzymes

These initial reports of enzyme sensitization and development of clinical symptoms in and out of the workplace eventually led to recognition of the importance for better dust control in order to reduce potential worker exposures. Thus, workplace structural and procedural changes were implemented within a short time. These included manufacturing equipment enclosures, improved work area exhaust ventilation systems, operational methods for safe handling of enzymes, and novel enzyme coating methods to reduce enzyme friability and dust generation (8,9). The American Conference of Governmental Industrial Hygienists (ACGIH) implemented a threshold limit value (TLV) for subtilisin of 60 ng/m3, further driving improvements in exposure control methodologies (10). The detergent industry has implemented a self-imposed exposure guideline of 15-20 ng/m3. Despite these preventive measures, plant physicians continued to report enzyme sensitization (e.g., skin prick test responses) in exposed workers. These findings led to the understanding that all workers exposed to enzymes should be medically monitored at regular intervals for enzyme sensitization in conjunction with strict control and enforcement of

standard operating procedures to prevent airborne enzyme dust in the workplace (11,12). In fact, manufacturers of enzyme-containing detergent products represent the first industry that voluntarily implemented the immunosurveillance programs designed to identify and monitor sensitized enzyme workers. These programs enabled the immediate removal of clinically symptomatic enzyme-sensitized workers from further enzyme exposure in the workplace. Immunosurveillance programs have also been successful in establishing safer operating guidelines in the enzyme industry that has further reduced the risk for enzyme sensitization of exposed workers (13,14).