METHODS OF MEASURING BIOLOGICALLY ACTIVE ENZYME DUST IN THE ENVIRONMENTAL AIR OF DETERGENT FACTORIES A Working Party under the auspices of the Soap and Detergent Industry Association:

Abstract—Improvements to the analytical method for detecting enzymes in the environmental air of enzyme detergent factories and the air sampling instruments and procedures used by the detergent industry are described. The sensitivity of the analytical method for the determination of proteolytic enzymes in dust samples has been increased by a factor of 10. This stretches the technique to its limits and the analytical difficulties of determining such low enzyme levels in dust are discussed. The detection limits for both Galley and Casella air samplers are calculated but these are not invariant; factors affecting these limits are included. The enzyme activity of samples collected by air filtration using high volume static samplers and low volume samplers v/orn by operating personnel or located statically alongside the high volume samplers arc compared. The low volume personal sampler gave higher results and the reasons for this are examined. There is good reproducibility between instruments with the same basic operating principles and flow rates. Particle size determinations with an impact plate sampler indicate that about 50 % of the total airborne dust is in the respirablc range and 70 % of the proteolytic enzymes in the dust sample is contained in this respirable fraction. An instrument for continuous measurement of enzyme dust has been designed and con-structed. It shows that peak emissions of enzymes occur and that they decay rapidly. The instrument is extremely useful for locating and eliminating these peak emissions. The requirements for a routine monitoring programme in a detergent factory are discussed with details on the location of samplers, duration and frequency of sampling, calibration and maintenance of samplers and sampling procedures