Millions of Americans use respirators in their places of work to protect themselves from exposures to such respiratory hazards as toxic vapors and gases, harmful particulate matter, and airborne pathogens. Some respirators filter the ambient air, while others employ a separate air supply; but in either case the respirator will protect its user only if it fits properly. It must mold to the user’s face in such a way that no air from the outside can leak in, even when the user is moving or speaking.

It is the responsibility of the National Institute for Occupational Safety and Health (NIOSH) to certify that respirators from manufacturers meet certain minimum performance levels. NIOSH performs this task with the help of fit-test panels, each of them a group of about 25 people who have been chosen because, collectively, their facial dimensions are assumed to be representative of the respirator-wearing workforce as a whole. In 2001 NIOSH contracted with Anthrotech, Inc., to collect new anthropometric data that would be representative of today’s respirator-wearing workforce and to use those data to design new fit-test panels. After Anthrotech finished that task, NIOSH contracted with the Institute of Medicine (IOM) to establish an ad hoc committee to review the NIOSH-sponsored Anthrotech study. This report contains the findings, conclusions, and recommendations of that IOM committee.

The various elements of the NIOSH-sponsored Anthrotech study—anthropometric measurements, statistical sampling techniques, fit testing, and so on—are complicated, and this review must necessarily wade into them in some detail; but the basic message of this report can be summarized with the following three broad statements: 

1. the results of the NIOSH-sponsored Anthrotech study represent a clear improvement over the anthropometric data and corresponding LANL fit-test face panels that have been used since the 1970s;

2. nonetheless, the NIOSH-sponsored Anthrotech study has a number of weaknesses that limit its effectiveness and reliability; and, therefore,

3. there are certain steps that should be taken to address the weaknesses, in order to move toward more effective testing and certification of respirators in the future.