Distribution of Faceseal Leak Sites on a Half-Mask Respirator and Their Association with Facial Dimensions

Abstract

Faceseal leaks on one brand of half-mask respirator worn by 73 human subjects were identified by deposition of a fluorescent tracer aerosol during a standard quantitative fit test. The identified leaks were categorized according to their location and shape. It was found that about 89% of all observed leaks occurred at the nose or chin or were multiple leaks which included these sites. Fit factors for these types of leaks were significantly lower than for other types of leaks. About 73% of all leaks approximated the shape of a slit rather than a round orifice, and the prevalence of these leaks was affected by gender. Significant association of facial dimensions and leak sites were found. Most of these were attributed to differences in gender, and only a very small percentage were for the facial dimensions used to define the Los Alamos respirator test panel. Significant correlation of facial dimensions and fit factor were found for only three facial dimensions; none of which are used to define the test panel. Evidence of airflow streamlining within the facepiece was observed on 22% of the subjects. Results of this study indicate that respirator leakage is strongly affected by nose and chin leaks, that gender is a factor in how a respirator fits, and that consideration should be given to including nasal dimensions when defining a respirator test panel and selecting a respirator for an individual wearer.

Facial Anthropometric Dimensions of Koreans and Their Associations with Fit of Quarter-Mask Respirators.

“…But several studies 4,5,10) have reported that the facial dimensions used for half mask design showed no relationship to the fit performance of half masks. Confounding the problem is the fact that the data were originated mainly from military personnel, where variability in terms of age, weight, and height might have been much less than that of civilians.…”

“…1. These dimensions have been shown to closely related to the performance of quarter and half mask respirators 5,9) . To reduce interpersonal variations facial anthropometric data were collected by one person, who was trained for facial dimension measurements from the Anthropology Research Project, Inc., (Yellow Springs, OH 45387, USA).…”

“…In designing the facepiece of a respirator, the facial dimensions selected for full facepiece respirators were face length and face width, and for half-and quarter mask respirators were facial length and lip width 3) . Previous studies on the seal of tight-fitting respirators to wearers' faces have focused mainly on White (Caucasian) males 4,5) . A review of literature revealed that only a limited amount of research on other ethnic groups including Blacks, Hispanics, and Asians have been done [6][7][8][9] .…”

Technology Survey for Enhancement of Chemical Biological Radiological and Nuclear Respiratory Protection

“…Several studies have been performed to characterize the effect of facial dimensions on respirator fit (Oestenstad, et al, 1990;Han and Choi, 2003;Zhuang et al, 2005), but a clear relationship has not been established due to the variability of facial characteristics. This variability is one reason why a mask that actively seals or conforms to the wearer's face is desirable.…”

Filtering Efficiency of N95- and R95-Type Facepiece Respirators, Dust-Mist Facepiece Respirators, and Surgical Masks Operating in Unipolarly Ionized Indoor Air Environments

“…The respirator performance has been extensively studied over the years (Brosseau et al, 1989;Chen et al, 1994;Hinds et al, 1988;Huang et al, 1998;Johnson et al, 1994;Johnston et al, 2001; Lee et al, 2004c;Nicas et al, 2003;Oestenstad et al, 1990;Qian et al, 1997;Qian et al, 1998;Weber et al, 1993;Willeke et al, 1996). A wide variety of the disposable particulate respirators have been characterized with respect to their protection factor.…”