ensure that respirators certified by NIOSH fit as many respirator-wearing workers in today’s workforce as possible (Anthrotech, 2004).
This report is a review of that 2001 NIOSH-sponsored Anthrotech study.
Because it is not feasible to test the fit of a respirator on every worker who might use it prior to release, the historical practice has been to test each respirator’s fit against a representative collection of subjects who have faces of various sizes and shapes. In 1934, for instance, the U.S. Bureau of Mines issued its first test schedule for dust respirators (Schedule 21). Later, revised regulations required three men of differing facial features (lean, average, and full) to wear respirators in an atmosphere of coal dust (Bureau of Mines, August 20, 1934, and March 23, 1965). In the 1960s, tests for self-contained breathing apparatus and certain other types of respirators used 15 to 20 men with widely varying facial shapes and sizes to test the suitability of fit (Bureau of Mines, March 23, 1965). Other fit tests analyzed the subjects’ nasal secretions, and those that were free of coal dust were considered to have an appropriate fit (Drinker and Hatch, 1954). In 1972 new regulations (Code of Federal Regulations [CFR], 30 CFR 11) required facepieces to be designed and constructed in a range of sizes in order to fit persons with various facial shapes and sizes. Fitting requirements varied slightly from one type of device to another. For certain devices (such as gas masks and pesticide respirators), the manufacturer had the option to specify which facial sizes each mask was designed to fit, and the mask was then tested on faces in those size ranges (Code of Federal Regulations, 1972).
NIOSH and the Occupational Safety and Health Administration (OSHA) share responsibility for overseeing respiratory protection in the workplace and have established regulations for this purpose. Specifically, NIOSH has issued regulations which define respirator testing and certification in 42 CFR 84 (National Institute for Occupational Safety and Health, June 2, 1995). OSHA has issued regulations which define conditions under which employers are required to maintain respiratory protection programs in general industry (29 CFR 1910.134); shipyards (29 CFR 1915.154); marine terminals (29 CFR 1917.92); and construction (29 CFR 1926.103) (Occupational Safety and Health Administration, 1998). This report focuses on the establishment of the scientific base re-