Abstract
A multipurpose stainless-steel controlled-atmosphere exposure chamber was designed and fabricated. The chamber can be used for simultaneous exposure tests involving different types of active and passive industrial hygiene monitors. The ability to use different types of monitors was achieved through the use of interchangeable plug-in sample holders in the chamber. The dynamically controlled atmosphere test chamber is easy to operate. The chamber parameters, such as humidity, linear face velocity, and test-gas concentration, were stable over the entire exposure test period. The test contaminant concentration levels can be varied from low parts per billion (ppb) to high parts per million (ppm). Two application examples that used the newly designed exposure chamber are presented. The first example compares two methods for determining 1,3-butadiene concentrations. These methods were National Institute for Occupational Safety and Health (NIOSH) Method 1501 using SKC charcoal tubes and a thermal desorption method using passive dosimeters. The linear regression analysis of the data from the exposure chamber tests showed that the passive sampling methods were comparable to NIOSH Method 1501 for 1,3-butadiene monitoring. The second example illustrated an evaluation of the limit of detection (LOD) and the limit of quantitation (LOQ) for benzene monitoring using SKC active sampling charcoal tubes and 3 M OVM passive dosimeter badges. Both monitors were tested in the exposure chamber at low ppb concentrations. The average LOQ for 3 M and SKC monitors was found to be 0.006 and 0.009 ppm, while the average LOD was 0.002 and 0.003 ppm, respectively.