Respirator Fit: NIOSH Seeks Comments on Anthropometric Research
NIOSH is seeking comment on research to develop a representative database of facial sizes and shapes that will help in the design of respirator face masks for the increasingly diverse U.S. employee population. The research plan responds to issues and recommendations in an April 2007 report by the Institute of Medicine, which represented findings from an independent review commissioned by NIOSH and addressed research at NIOSH's National Personal Protective Technology Laboratory (NPPTL).
In 2001, NPPTL initiated a study to develop an anthropometric database of the heads and faces of civilian respirator users to update the respirator fit test panels. A total of 3,997 subjects were recruited from industries and public services in which workers routinely or occasionally use respirators. Subjects were obtained at 41 separate sites, located in eight states from the east to west coasts of the United States. Subjects were measured for 21 dimensions through the use of traditional measurement tools, and 1,013 of the total were scanned with a 3-D laser scanning system.
Based on the data collected, NPPTL researchers developed two new panels for half- and full-face respirator fit testing. One of the new panels (a NIOSH bivariate panel) included the same linear measurements used for the respirator certification program by the Los Alamos National Laboratory (LANL panel). The other panel recommended was based on establishing the appropriate facial features by using principal component analysis to identify the combination of facial dimensions that best represented the variation among the faces in the data set.
Because of the potential implications on the respirator users, manufacturers, and respirator market, NPPTL commissioned IOM through the National Academies to review the 2004 NIOSH report, "Assessment of the NIOSH Head-and-Face Anthropometric Survey of U.S. Respirator Users." NPPTL requested the committee to examine the adequacy and validity of the NIOSH study, the data collected, and the recommended revisions to the set of facial characteristics that are to be used in testing the fit of respirators. This review examined both the content and the form of the study, the appropriateness of its sample and its sample methodology, and the adequacy of the resultant data. Issues IOM was to address concerned whether the revised panel of facial characteristics is representative of the diverse U.S. workforce and the adequacy of the anthropometric features and parameters considered in the revised panel. NPPTL requested IOM to make recommendations concerning additional analyses that the PPT Program might undertake to obtain further information regarding the revisions to the respirator panel.
IOM completed the study and issued to NPPTL the preliminary report in January 2007 and the final report in April 2007 providing three overarching conclusions, among which was that the NIOSH-sponsored study had "a number of weaknesses that limit its effectiveness and reliability." IOM made a series of recommendations for maximizing the opportunity to incorporate the panel in current respirator certification. The committee also provided recommendations regarding future research opportunities. NPPTL is responding to IOM's report by developing an action plan for addressing the issues and recommendations described in the report. The action plan will provide a long-term strategy for facial anthropometrics and respirator fit research at NPPTL and will be used to prioritize and select future NPPTL research projects including funding, staffing, and upgrading laboratory capabilities.
Comments will be accepted until 5:00 p.m. EDT on Nov. 30. The draft action plan, the IOM report, further details about the NIOSH research, and contact information for submitting public comments are available at http://www.cdc.gov/niosh/review/public/111/. Based on the comments received, NPPTL will revise the action plan in January 2008.