5.1 In the U.S., when 42 Code of Federal Regulations Part 84 (42 CFR 84) was promulgated in 1995, the isoamyl acetate tightness test as described in 30 Code of Federal Regulations Part 11 for certain particulate-removing respirators was removed. These particulate-removing respirators were designed as protection against: (1) fumes of various metals having an air contamination level not less than 0.05 mg/m³, and (2) dusts, fumes, and mists having an air contamination level less than 0.05 mg/m³ or radionuclides. The isoamyl acetate test was removed because particulate respirators had to be modified before they could be tested and there were no other available fit tests suitable to the National Institute for Occupational Safety and Health (NIOSH) for approval testing at the time (1).4 There was a concern that the modified respirators may have had different fitting characteristics from the versions marketed. According to NIOSH, removing this requirement also allowed for further research on the effectiveness of certification fit testing methods (1).

5.2 NIOSH conducted benchmark testing of 101 respirator models on the market during 2008 and 2009, using a similar test to that described herein (2). The results were analyzed to develop key test parameters and pass/fail criteria options for a respirator fit capability test for half-facepiece air-purifying particulate respirators (3). According to NIOSH, approximately 30 % of the models tested did not have good fitting characteristics (2). This was also supported by published research (4, 5). This standard establishes a performance requirement called respirator fit capability to assess respirator face-sealing characteristics.

5.3 This standard can be used to evaluate all particulate-removing respirators on a population of wearers. A respirator model meeting the fit capability requirement will be capable of fitting the facial sizes and shapes for which it was designed. To achieve this goal, it is necessary for the method to reject poor-fitting respirators, while still passing well-fitting respirators meeting the pass/fail criteria established in this standard. It is thought that this standard will increase the likelihood that respirators meeting this requirement will fit a wide variety of their prospective wearers when properly fit tested, donned, and used.

1.1 This standard provides detailed instructions for performing a respirator fit capability test to determine the fit of air-purifying, half-facepiece respirators, which will include both filtering facepiece respirators and elastomeric respirators equipped with any type of particulate filter. The purpose is to increase the probability that available respirators fit a general worker population. The standard provides increased assurance to respirator purchasers and users that respirators that meet the requirement of this standard can be expected to effectively fit persons with various lengths and widths of faces, such as long and narrow or short and wide, when fit tested in the workplace as part of a complete respiratory protection program in accordance with 29 CFR 1910.134.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 It is the responsibility of the investigator to determine whether good laboratory practices (GLP standards—40 CFR, Part 160 of FIFRA) are required and to follow them when appropriate.

1.4 This standard does not address specific product performance standards established by regulatory authorities; see 2.2 for details.

1.5 This standard does not eliminate the need for every wearer to undergo a personal respirator fit test.

1.6 This standard does not guarantee that every respirator wearer will be able to achieve the required fit factor on a particular manufacturer’s single-size or multi-size respirator model. Respirator wearers must always be given the opportunity to try other models or other manufacturers’ respirators.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.