To develop the proposed respirator fit-test panels, NIOSH contracted with Anthrotech “to assess and refine the LANL fit-test panels,” relying on the same facial dimensions and utilizing methods similar to those used by the original LANL face panel designers (Zhuang, 2001). The rationale for choosing to assess and refine the LANL face panels, using the same parameters, and not consider using strategies that have been developed since the 1970s to develop the updated face panels was not clear to the committee. The NIOSH-sponsored Anthrotech report notes, however, that, unlike the LANL face panel, the proposed face panel was not confined to a strictly rectangular arrangement of cells (Anthrotech, 2004). They found that, in offsetting some of the cells, they were able to achieve a greater coverage of the target population. However, there was no discussion of whether the number of boxes is appropriate, or whether there may be problems of fit for persons near the edges of the boxes.

The updated full- and half-face panels proposed by the NIOSH-sponsored Anthrotech study were based on the menton-sellion length and bizygomatic breadth facial dimensions. The full-face panel accommodates 96.2 percent of the study population—that is, 96.2 percent of the nearly 4,000 workers recruited for the study have faces with a bizygomatic breadth and menton-sellion length that fall into one of the boxes of this panel (Figure 4-1). The revised half-face panel, which relies on menton-sellion length and lip length, accommodates 97.2 percent of the study population (Figure 4-2). As was done in the development of the LANL face panel, the NIOSH-sponsored Anthrotech study populated the individual cells so that the cells that represent larger percentages of the study population—the middle cells—were assigned more subjects than