Should an evaluation of fit be incorporated into the certification testing for respirators?
In October 2009, the National Institute for Occupational Safety and Health (NIOSH) proposed to add a test for Total Inward Leakage (TIL) to the certification process for half-mask air-purifying particulate respirators. NIOSH believes that adding this component to respirator testing will help ensure that more users will be able to get an adequate fit, and increase the level of protection for users who are not individually fit tested. ISEA believes the proposed rule would not achieve the goal of improving worker protection, would be difficult for employers to implement, and might have the unintended consequence of less workplace fit testing.
NIOSH has the authority to test and approve respiratory protection devices used by workers, under 42 CFR part 84. OSHA requires that respirators used in the workplace be NIOSH approved, and further requires that workers be individually fit tested as part of the respirator selection process. Total inward leakage is defined as the combination of contaminated air that leaks through a respirator from various sources, including face seal, valves and gaskets, and penetration through the filter. Because a respirator’s performance is largely dependent on its fit to an individual user, there is no test for TIL in the NIOSH approval.
For a number of years, NIOSH has been studying
whether such a test could be feasibly added to the certification requirements. The agency believes that a certification fit test will eliminate respirator models that are inherently poor-fitting, and increase the likelihood that approved respirators will fit a larger number of users. In benchmark testing, NIOSH found wide variability among half-mask respirators. Using the results of this testing, it drafted a proposed rule
that was published on October 30, 2009. A public meeting was held in December 2009, and comment period, initially ending December 29, was extended to March 29, 2010. In a January 2010 petition to the Secretary of Health and Human Services
, ISEA asked for a one-year extension of the comment period. NIOSH reopened the docket
, scheduling an additional public meeting in July 2010 and accepting comments until September 30, 2010.
The NIOSH Proposal
NIOSH proposes procedures for testing to limit approval to respirators that will have a high probability of fitting a large majority of users in a group. The group would be identified by the manufacturer based on facial shapes and sizes. Using the information supplied by the manufacturer, NIOSH would conduct testing on subjects chosen match the target group, e.g. sex, general facial characteristics and facial measurements. For respirators aimed at the general population, 35 subjects would be tested. For respirators aimed at specific subpopulations, 15 subjects would be tested. The respirator passes if 80% of test subjects achieve a fit factor of 100. Fit factor is the ratio of test agent concentration outside the respirator to the concentration inside the respirator. A fit factor of 100 is equivalent to a total inward leakage of 1.0%.
ISEA commented on the TIL concept following a NIOSH public meeting in 2007. It expressed the belief that the proposed TIL certification would not enhance the efficacy of respirators or increase worker protection, while increasing the regulatory burden for employers. It found the proposed fit test panels and methods introduced a high degree of variability that had not been identified, quantified or controlled to assure reproducible results. ISEA recommended that NIOSH should not move forward with the project.
ISEA repeated its position at the public meeting held on December 3, 2009, noting issues unresolved from its August 2007 comments. In its testimony
, ISEA suggested that the proposed changes to certification could actually result in less workplace fit testing, and make respirator selection more complex for employers. To further underscore its belief that the proposed tests were inadequate, ISEA’s Respiratory Protection Group commissioned an independent analysis by Environmental Health & Safety, Inc. For this study, the researchers analyzed available data from the NIOSH benchmark tests, and conducted a full series of TIL tests on two models of half-mask respirators. The results of the analysis were included as part of ISEA’scomments to the docket
submitted March 29, and were further explained at the July 2010 public meeting.
The researchers found that the proposed NIOSH criteria are overly stringent, and would likely exclude almost all filtering facepiece respirators and half of elastomeric facepiece respirators from the market. ISEA suggested modifying the pass-fail criteria and fit factor as a more reasonable approach. ISEA made other recommendations to change the test protocols, based on the findings of the researchers.
ISEA also addressed the larger question of whether having a fit test as part of certification will increase the likelihood that non-fit-tested users will be protected. Given the way the testing would be conducted, and lack of data on the effects of training and experience on the level of fit, there is not convincing evidence that adding a TIL test would lead to better chances that non-fit-tested users would get a better fit or be adequately protected. ISEA questions whether NIOSH should address the issue of adequate fit at all, as the use of respirators is under OSHA’s purview and should be addressed by that agency’s standards and enforcement activities. The association recommends that NIOSH use its research capabilities to improve fit testing at the user level, work with OSHA, MSHA and employers to educate employers and workers about the need for fit testing, and promote enforcement of respiratory protection standards and regulations.
On September 30, 2010, ISEA submitted additional comments to the docket challenging the NIOSH assumption that the proposed rule is not economically significant. ISEA presented data from the Respiratory Protection Group estimating that the TIL proposal’s economic impact could exceed $1 billion.
ISEA staff contact:
September 30, 2010