Objectives-To assess the prevalence of enzyme sensitisation in the detergent industry. Methods-A cross sectional study was conducted in a detergent factory. Sensitisation to enzymes was examined by skin prick and radioallergosorbent (RAST) tests. 76 Workers were tested; 40 in manufacturing, packing, and maintenance, and 36 non-exposed people in management and sales departments. The workers were interviewed for work related respiratory and skin symptoms. Total dust concentrations were measured by a gravimetric method, and the concentration of protease in air by a catalytic method. Results-Nine workers (22%) were sensitised to enzymes in the exposed group of 40, whereas none were sensitised in the non-exposed group. All the sensitised people had symptoms at work; all had rhinitis and one had asthma. Protease concentrations were generally <20 ng/m 3 , but occasional peak values up to 80 ng/m 3 were detected in the packing and maintenance tasks, and high values of >1 µg/m 3 in the mixing area. Conclusion-Despite the use of encapsulated enzyme preparations, high enzyme concentrations in workplace air are possible, resulting in a higher risk of sensitisation than expected. (Occup Environ Med 2000;57:121-125) Keywords: detergent enzymes; occupational exposure; allergyThe detergent industry was the first to give rise to the protease enzyme allergy problem in the late 1960s.1-5 Later, other enzymes, such as -amylases and cellulases emerged as sensitisers-for example, in the baking industry. [6][7][8][9] In the detergent industry, the allergy problem has been considered to be under control since the mid-1970s, due to development of encapsulated protease preparations and improvements in industrial hygiene.4 10 11 It was, however, reported that sensitisation could not be totally prevented by encapsulation of enzymes, 12 and some cases of respiratory allergy have been reported. 13 Recently, new enzymes have been introduced in the detergent industry-such as lipases in the late 1980s, and later cellulases and -amylases-although the proteases derived from Bacillus subtilis are still the most important enzymes. Because of the history of enzyme allergy and the increased range of enzymes in the field, we assessed the prevalence of sensitisation to enzymes and the levels of exposure to protease in a detergent factory.
Material and methods
DETERGENT FACTORYThe study was carried out in a factory producing laundry detergents and automatic dish washing detergents. The factory had been operating since the 1960s. New facilities were built in the mid-1980s. Detergents for laundry and dish washing were produced in separate departments. The manufacturing of laundry detergents includes mixing of raw materials with water and subsequent spray drying of the slurry, followed by addition of heat labile components such as enzymes. The addition of enzyme to the hopper took place manually a few times in a shift. Further mixing to the detergent was automated. The packing machines were controlled and operated by packers. The factory had mod...