Shotwell H P, Caporossi J C
Am Ind Hyg Assoc J. 1983 Feb;44(2):147-9. doi: 10.1080/15298668391404545.
Occasionally, airborne contaminant concentrations cannot be reduced to desired levels, even after the installation of feasible engineering controls. The industrial hygienist may have to recommend full-shift or partial-shift use of appropriate respirators to reduce exposures. The method described allows the industrial hygienist to recommend the minimum period of time an exposed employee needs to use a respirator in order to reach the desired exposure level. The procedure is based on the calculation of Time-Weighted Averages, using the upper confidence levels of air sampling data, and the respirator protection factors.
有时，即使安装了可行的工程控制措施，空气中污染物的浓度仍无法降低到理想水平。工业卫生学家可能不得不建议在整个班次或部分班次使用合适的呼吸器，以减少接触。所描述的方法使工业卫生学家能够推荐暴露员工使用呼吸器以达到理想接触水平所需的最短时间。该程序基于时间加权平均值的计算，使用空气采样数据的上置信水平和呼吸器防护因数。
