Respirator Efficiency Measurement Using Quantitative DOP Man Tests

The efficiency of high-performance dust respirators has been measured while the wearer performed specific exercises in a quantitative DOP aerosol man test chamber. The atmosphere in the respirator facepieces was sampled continuously, and the facepiece leakage was measured with a light-scattering photometer. Leakages of less; than 0.01% were detectable. The results of over 1500 tests on 150 subjects indicate that this method provides an accurate and meaningful measurement of respirator efficiency. Size measurements were made on the five half-mask respirators, each available in one size, and they were classified as small, medium, or large. With these respirators, 97 to 100% of the subjects obtained an efficiency of 90% or greater. Wearing the six approved full-facepiece respirators, 76 to 97% of the subjects obtained an efficiency of 99% or greater. Other variables which affect respirator efficiency are discussed, such as face size and shape, the type and tightness of headbands, and facial hair.