A new sampling technique that allows quantitative fit testing by using the employee's own respirator.

A new, in-mask sampling technique has been developed that enhances current quantitative respirator fit test methods. This new sampling technique eliminates the need for a permanently modified (probed) respirator for conducting fit tests. With this new technique, a sample was drawn from the breathing zone inside the respirator by means of a sampling adapter, which was temporarily attached between one of the air-purifying filters and the facepiece before a fit test was performed. To ensure that the performance of the respirator was not altered, the sampling adapter was designed so that all major functional aspects of the respirator were unchanged. This new sampling technique was evaluated on human test subjects by simultaneous sampling from a probed respirator by using two quantitative respirator fit test instruments. One instrument sampled through a conventional respirator probe; the other used the new method. Test results show that equivalent fit test data were obtained with both sampling techniques.