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Designing and Engineering Effective PPE

Understanding workplace hazards is critically important to ensuring that personal protective equipment (PPE) is available to healthcare personnel facing an influenza pandemic or other hazardous working conditions. Research on the transmission and virulence of the influenza virus and other potential infectious agents (Chapter 2) will inform decisions on the design and engineering of healthcare PPE.

As innovative approaches begin to address the PPE challenges of the healthcare workplace, further efforts are needed that focus on how to address the unique or varied issues that healthcare personnel face—easy communications with patients and families, PPE that can be changed or reused between different patients, PPE that is comfortable during long wear times, and PPE that does not interfere with work performance. Healthcare personnel are not alone in having job-specific PPE requirements. Firefighters need PPE that addresses high temperatures, construction workers on roofs and high-rise structures need protection from falls, and both have many other PPE requirements. Innovations in healthcare PPE are starting to be seen in the marketplace, but much more needs to be done to move the design of PPE from an industrial perspective toward the realities of the healthcare workplace.

This chapter focuses on research on designing and engineering effective PPE. The chapter begins with a brief overview of the 2008 report, followed by a synopsis of research that has been conducted in the past several years. The chapter concludes with the committee’s thoughts on research gaps and immediate and long-term research directions.



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3 Designing and Engineering Effective PPE Understanding workplace hazards is critically important to ensuring that personal protective equipment (PPE) is available to healthcare per- sonnel facing an influenza pandemic or other hazardous working condi- tions. Research on the transmission and virulence of the influenza virus and other potential infectious agents (Chapter 2) will inform decisions on the design and engineering of healthcare PPE. As innovative approaches begin to address the PPE challenges of the healthcare workplace, further efforts are needed that focus on how to address the unique or varied issues that healthcare personnel face—easy communications with patients and families, PPE that can be changed or reused between different patients, PPE that is comfortable during long wear times, and PPE that does not interfere with work performance. Healthcare personnel are not alone in having job-specific PPE require- ments. Firefighters need PPE that addresses high temperatures, construc- tion workers on roofs and high-rise structures need protection from falls, and both have many other PPE requirements. Innovations in healthcare PPE are starting to be seen in the marketplace, but much more needs to be done to move the design of PPE from an industrial perspective toward the realities of the healthcare workplace. This chapter focuses on research on designing and engineering effec- tive PPE. The chapter begins with a brief overview of the 2008 report, followed by a synopsis of research that has been conducted in the past several years. The chapter concludes with the committee’s thoughts on research gaps and immediate and long-term research directions. 71

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72 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL BACKGROUND AND CONTEXT FROM THE 2008 REPORT The 2008 Institute of Medicine (IOM) report provided the outline for a lifecycle approach to PPE and emphasized that, in addition to fit and filtration for respirators and functionality requirements for other types of PPE, numerous other factors play a significant role in the design and de- velopment of healthcare PPE. These factors include issues involving vis- ibility, comfort and wearability, durability, maintenance and reuse, aes- thetics, and cost (Figure 3-1). In considering a framework for the design and development of PPE, the 2008 committee addressed the three phases of the design and engi- neering process typically associated with a product’s lifecycle: • Protect against • Maintain biomechanical • Comfortable—no skin • Adequate wear life • Strength—tear, influenza virus efficiency and sense of touch irritation or pressure • Guard against and feel points tensile, burst • Odor-free • Abrasion resistance • Prolonged use contact with • Hypoallergenic • Corrosion contaminated without discomfort • Accommodate wide range of • Breathable—air resistance fluids and aerosols users (face and body profiles) permeable • Compatibility across various • Moisture absorbent— elements of the PPE wickability • Low bulk and weight ensemble and with other • Dimensional stability equipment (e.g., stethoscope) • Non-startling to patients and • Easy to put on and families take off (don and doff) • Facilitates communication with others (verbal, facial) • Variety of styles • Product cost • Easy to • Total lifecycle and colors • Customizable decontaminate and cost • Minimal environ- discard disposable elements mental impact • Easy to clean and replace parts in reusable PPE FIGURE 3-1 A structured approach to evidence-based performance require- ments for personal protective equipment (PPE). SOURCE: IOM (2008).

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73 DESIGNING AND ENGINEERING EFFECTIVE PPE 1. User requirements analysis: understanding the work hazards and barriers to PPE use; 2. Design realization: identifying the key characteristics (Figure 3-1) and translating the evidence-based performance require- ments into the specific design of the PPE component while mak- ing appropriate trade-offs among the factors that drive design, including degree of protection, comfort, and the cost of design- ing the specific PPE component to meet the regulatory require- ments; and 3. Field use and evaluation: requiring that the new PPE be tested in the field in order to provide a realistic assessment of its per- formance and to identify unintended consequences of use. Fit and filtration are the major functional issues in the design and en- gineering of respirators. Most research has focused on filtration. National Institute for Occupational Safety and Health (NIOSH) ratings for respira- tors of 95, 99, or 100 percent filtration efficiency are based on the per- centage of 0.3 μm particles that do not penetrate the test filter (IOM, 2008). Influenza viruses, with estimated sizes ranging from approximate- ly 0.08 to 0.12 μm (although droplets with the virus can vary widely in size), follow standard particle filtration theory, and therefore a number of types of filters are effective. Less is known about issues regarding inward face seal leakage and other aspects of respirator fit. The 2008 report rec- ommended research on a number of respirator issues, including deconta- mination and reuse methods, comfort and tolerability concerns, powered air-purifying respirators (PAPRs) designed to meet the needs of health- care personnel, and improved face seals. The 2008 report also addressed research for gowns, gloves, eye pro- tection, face protection, and other types of PPE that might be needed to protect workers from infectious disease. These types of barrier protection are designed primarily to protect against droplet spray and contact trans- mission that might occur when particles are transferred to the respiratory mucosa or conjunctiva (of the eyes) of susceptible individuals within close range. Testing of gowns has focused primarily on liquid barrier performance and breathability of the fabric, with four levels of liquid barrier performance defined by the Association for the Advancement of Medical Instrumentation’s (AAMI’s) testing standard, AAMI PB70. The prior report emphasized the need to explore whether specific clinical sit- uations require varying types of gowns or whether other specifications are needed, as well as issues regarding feasibility of reuse, interface with

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74 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL other types of PPE (especially gloves), and advances in materials tech- nology, including repellant finishes (IOM, 2008). For protective eye- wear, including transparent face shields, issues regarding the interface with respirators were found to be a critical need. In addition, product per- formance standards for eye protection need to be defined more clearly because they now focus on the thickness and impact resistance of eye protection but do not address issues relevant to influenza transmission (IOM, 2008). Healthcare personnel’s use of gloves can serve several purposes in infection control—creating a barrier to direct contact with contaminated surfaces, preventing patient-to-patient contamination if gloves are changed between patients and proper hand hygiene is performed, and increasing awareness of the potential for self-inoculation when gloved hands touch the mucosa of the mouth, nose, or eyes. Research needs re- garding gloves that were identified in the 2008 report included better bar- rier protection as well as wearability and improved interfaces with gowns and other PPE. Adherence to hand hygiene and other infection control practices are also important in preventing disease transmission. The 2008 report provided a list of immediate opportunities and long- term research needs for improving the design and effectiveness of healthcare PPE. The report also provided a set of recommendations in this area, which can be briefly summarized as follows: • Define evidence-based performance requirements for PPE. • Adopt a systems approach to the design and development of PPE. • Increase research on the design and engineering of the next gen- eration of PPE. • Establish measures to assess and compare the effectiveness of PPE. UPDATE ON RECENT RESEARCH Research efforts since the prior report have continued to address a range of design and engineering issues with the goal of improving the PPE available to healthcare personnel and others. The following section provides an overview of recent research efforts, beginning with the re- search focused on respirators and face masks.

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75 DESIGNING AND ENGINEERING EFFECTIVE PPE Respirators and Face Masks: Fit and Filtration The protection provided by a particular respirator is a function of both the filtration capabilities of the material and how well the device fits the wearer. Total inward leakage (TIL) is the combination of filtration, face seal leakage, and leakage through respirator components, such as the exhalation valve. Filtration Several issues concerning filtration have been raised recently. First, the filtration efficiency of face masks is a concern because they are not developed as filtration devices. Second, researchers have been concerned about the penetration of nanoparticles (which includes the size range of influenza and other viruses) through respirator filter media and whether current NIOSH respirator certification methods accurately account for those particles. Third, shortages of respiratory protection may occur dur- ing a pandemic, so alternative filter materials and equipment have been investigated. Filtration efficiency of face masks Two recent studies investigated the filtration efficiency of face masks. Oberg and Brosseau (2008) evaluated filtration performance of nine face masks (cup, flat, duckbill, one and two straps, ear loops, surgical, laser, and procedure). Filter efficiencies ranged from 0 to 84 percent for the latex sphere tests and 4 to 90 percent in the sodium chloride (NaCl) tests. Dental masks showed significantly higher penetration (6 to 75 percent for latex and 53 to 90 percent for salt) than hospital masks (0.02 to 0.7 percent for latex and 4 to 37 percent for salt). Only 1 of the hospital masks (mask H) had less than 5 percent pen- etration of the salt particles. Lee and colleagues (2008c) investigated the protection factor of face masks and respirators with a challenge of par- ticles representing bacterial and viral size ranges (aerodynamic size: 0.04 to 1.3 µm) and found that none of the masks had protection factors > 10. The protection factors of the tested N95 respirators were an average of 8 to 12 times greater than those of masks. One previous study (Li et al., 2006) reported that face masks provided 95 percent filtration efficiency for potassium chloride. However, Brosseau and Harriman (2007) pointed out that the study did not use a standard method and that the authors did not fully describe the technique. None of the face masks tested by Oberg

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76 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL and Brosseau (2008) or Lee and colleagues (2008c) provided sufficient protection to be considered respirators. This is not surprising considering the fact that face masks were not intended to be respiratory protective equipment. Penetration of small particles NIOSH certification tests for N95 respi- rators use an NaCl aerosol challenge with a 300 nm most penetrating particle size (MPPS). 1 However, many electret filter media that use elec- trostatic charge to capture particles have an MPPS ranging from 30 to 100 nm (Shaffer and Rengasamy, 2009). Concerns have been raised re- garding the filtration performance of N95 respirators against smaller viral- and bacterial-sized particles. Eninger and colleagues (2008b) re- viewed the NIOSH aerosol particle-size distribution and measurement method. The authors found that, although the salt aerosol does contain a significant fraction of ultrafine (diameters < 100 nm) particles, the method and equipment used cannot accurately measure the contributions of par- ticles below 100 nm. In fact, 68 percent by count and 8 percent by mass of salt particles below 100 nm did not significantly contribute to the filter penetration measurement. Therefore, the existing NIOSH certification protocol may not adequately reflect the penetration of ultrafine particles. Several groups of researchers have investigated the filtration perfor- mance of respirators against nanoparticles. Eninger and colleagues (2008a) investigated the filtration performance of one N95 and two N99 filtering facepiece respirators against one inert particle and three virus aerosols at flow rates of 30, 85, and 150 L/min. The respirators were sealed on a manikin. The most penetrating particle size for challenge aerosols was < 0.1 µm for all three respirators. Mean particle penetration, by count, was increased significantly when the size fraction of particles 0.1 µm. Penetration of the salt aerosol was greater than that of the tested biological aerosols, suggesting that inert aerosols can be used to assess filter penetration of virions. Inhalation airflow rate had a significant effect on particle pene- tration. The authors suggested that further research is needed with cyclic flows with high peak inspiratory flows. A study of the filtration performance of five N95 and two P100 fil- tering facepiece respirators against monodisperse silver aerosol particles 1 The MPPS is the particle size that has the lowest filtration efficiency. Particles near the MPPS are too large to be efficiently captured by diffusion, but they are too small to be efficiently captured by the filtration mechanisms of impaction and interception.

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77 DESIGNING AND ENGINEERING EFFECTIVE PPE in the 4 to 30 nm range at 85 L/min found that both types of respirators showed a decrease in percentage of penetration, with a decrease in par- ticle diameter down to 4 nm (Rengasamy et al., 2008). This study sup- ports prior studies that indicate that NIOSH-approved air-purifying respirators provided expected filtration protection against nanoparticles. A follow-up study using a polydisperse NaCl aerosol test with a 238 nm mass median aerodynamic diameter and two monodisperse aerosol tests concluded that the eight filtering facepiece respirator models tested met expected filtration performance against nanoparticles (Rengasamy et al., 2009). The NIOSH-certified respirators have a minimum efficiency of 95 percent for the N95 and 99.97 percent for the P100. The European Norm requires a minimum efficiency of 94 percent for a filtering facepiece res- pirator class P2 (FFP2) and 99 percent for a filtering facepiece respirator class P3 (FFP3). Penetrations from the polydisperse aerosol test were < 1 percent for the N95 and FFP2 models and < 0.03 percent for the P100 and FFP3 models. In a study by Eshbaugh and colleagues (2009), the researchers ex- amined the effects of varying flow conditions on aerosol penetration for both N95 and P100 filtering facepiece respirators and cartridges. Chal- lenges were inert solids and oil aerosols with particle sizes in the range of 0.02 to 2.9 µm; three constant flow and four cyclic flow conditions were used. Penetration increased under increasing constant- and cyclic- flow conditions. The MPPS for the P100 filters was 50 to 200 nm and 50 nm for N95 filters. Shaffer and Rengasamy (2009) reviewed research published since 2000 on respirator filtration and leakage data for nano- particles. The MPPS was in the 30 to 100 nm range and was impacted by the filter media and test conditions, particularly flow rate. They found that filtration of monodisperse nanoparticles at the MPPS varied from 1.4 to 10 percent for the N95 filtering facepiece respirator. They identified the greatest need for further research as human laboratory or workplace protection factor studies to measure TIL for respirators used for protec- tion against nanoparticles. Wander and Heimbuch (2009) tested one N95 and one P100 filtering facepiece respirator with aerosolized particles (count mode diameter ~0.8 µm) of H1N1 and inert beads at 85 L/min using the Laboratory-Scale Aerosol Tunnel. The N95 removed > 99 per- cent of viable H1N1 while the P100 removed > 99.99 percent. They per- formed the same against the inert beads. The authors concluded that infectious microorganisms and inert particles of the same size have the same impact on the filtering efficiency of filtering facepiece respirators.

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78 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL Although these studies used different challenge aerosols and differ- ent test methods, several common results emerge. Inhalation airflow rate had a significant effect on particle penetration (Eninger et al., 2008a; Eshbaugh et al., 2009). NIOSH- or European Norm–certified filtering facepiece respirators achieved expected filtration performance when challenged with nanoparticle aerosols (Eninger et al., 2008a; Eshbaugh et al., 2009; Rengasamy et al., 2008, 2009). The MPPS is below 100 nm for most electret filter media (Eninger et al., 2008a; Eshbaugh et al., 2009; Rengasamy et al., 2009), though one researcher (Eshbaugh et al., 2009) reported 200 nm for two models of filtering facepiece respirators. Final- ly, inert particles have penetration performance similar to virus particles (Eninger et al., 2008a; Wander and Heimbuch, 2009). Alternative filter materials In the event of a pandemic, there may not be enough respirators available to meet demand. Rengasamy and col- leagues (2010a) examined the filtration performance of common cloth materials, such as sweatshirts, T-shirts, towels, scarves, and cloth masks, against nanoparticles using polydisperse and monodisperse aerosols (20 to 1,000 nm) at two face velocities. The cloth materials had penetration levels of 40 to 90 percent for polydispersed NaCl, well above that of N95 respirators. Penetrations of 9 to 98 percent were obtained for different monodisperse NaCl aerosol nanoparticles. These materials had penetra- tion levels similar to some face masks that were tested previously. They concluded that only minimal protection would be provided by wearing masks made out of these cloth materials, especially when considering that face seal leakage will decrease protection further. Fit Face seal leakage is a critical factor in the amount of protection pro- vided by a respirator. Although much research has been done on filtering media and improving filter efficiency, the fit side of the equation has not been explored in such depth. Several recent studies examined aspects of fit related to healthcare personnel. Face masks Two recent studies examined the extent to which face masks fit the face. Duling and colleagues (2007) assessed six face masks. The simulated workplace protection factor fifth percentile value was 1.4 and the lower 90 percent confidence limit was 1.2, indicating that none of the

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79 DESIGNING AND ENGINEERING EFFECTIVE PPE masks provided adequate protection. Oberg and Brosseau (2008) eval- uated facial fit of 5 face masks using qualitative and quantitative fit tests with 20 human volunteers. When the subjects put on the face masks themselves, they all failed the qualitative fit test. When they were as- sisted with donning the face masks, 18 subjects failed the fit test. For unassisted donning, average quantitative fit factors were 2.5 to 6.9; for assisted donning, they ranged from 2.8 to 9.6. None of the masks tested attained an individual fit factor of 100, the minimum passing level re- quired by the Occupational Safety and Health Administration (OSHA) for a half-mask filtering facepiece respirator. Loose-fitting PAPRs Loose-fitting PAPRs may be worn by healthcare personnel who have beards or who cannot otherwise wear an N95 filtering- facepiece or elastomeric air-purifying respirator. The unfiltered, exhaled air from the PAPR may transmit virus from the wearer to others. An N95 respirator may be worn inside the PAPR to prevent this from happening. Roberge and colleagues (2008) used a manikin to assess the protection factor of a loose-fitting PAPR with and without an N95 respirator glued to the manikin. Flow rates were 25 L/min and 40 L/min. The N95 signif- icantly increased the PAPR protection factor even when the PAPR blow- er was turned off. However, consideration should be given to the possible negative impact of the additional physiological burden of wear- ing an N95 respirator inside a PAPR (Roberge, 2008). Additionally, their results might not hold in the work setting because the N95 was glued to the face (Roberge et al., 2008). Some loose-fitting PAPRs do not fully encapsulate the head, making it possible for the wearer to overbreathe the blower and possibly be exposed to contaminants (Roberge et al., 2008). Johnson and colleagues (2008) found that the 1.1 L of air inside the loose-fitting PAPR they tested would act as a buffer against contami- nated air that leaks into the respirator due to overbreathing the blower. That volume could also help if an N95 were worn under the PAPR and face seal leaks occurred. Fit testing and inward leakage Several large-scale fit tests of health- care personnel were completed recently (Lee et al., 2008b; McMahon et al., 2008; Oestenstad et al., 2007; Wilkinson et al., 2010; Winter et al., 2010). McMahon and colleagues (2008) found that 5 percent of men and 15 percent of women could not pass the fit test with the first respirator tried, while Lee and colleagues (2008b) had 26 percent of workers fail the fit test with the first respirator. Winter and colleagues (2010) found

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80 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL that 28 percent of 50 staff members did not fit the 3 respirators tested. Wilkinson and colleagues (2010) found that 82.9 percent of 6,160 healthcare personnel were successfully fitted with the first respirator, 12.3 percent required testing with a second respirator, and 4.8 percent required testing with 3 or more respirators. Therefore, multiple respira- tors are likely to be needed to get passing fit tests for all staff. First-time pass rates may improve after NIOSH incorporates the new sizing panels (Zhuang et al., 2007, 2008) into its TIL certification requirement. Gender and age in women may be significant factors in achieving a successful fit (McMahon et al., 2008), though Oestenstad and colleagues (2007) did not find a gender difference in the 41 subjects they tested. Gender, respirator brand, and test repetition did not have any significant effects on location or shape of leaks assessed on half-mask respirators using a fluorescent tracer during fit tests (Oestenstad and Bartolucci, 2010). There was a difference in fit test leak-site distribution for women, and the authors suggested that facial dimensions may be an important factor. In fact, their prior research showed that fit was significantly asso- ciated with face length and lip width and possibly face width (Oestenstad et al., 2007). Weight gain during pregnancy may impact fit due to changes in facial anthropometrics (Roberge, 2009). Wilkinson and col- leagues (2010) found that personnel who reported their race as Asian had the highest failure rate and that race was correlated with facial shape. Training improved the fit test pass rate (Lee et al., 2008b; Winter et al., 2010). However, as time elapsed from the fit test, pass rates were similar to those prior to training, although frequent use after training led to in- creased pass rates (Lee et al., 2008b). Experience of the fit testers was found to be a significant factor in achieving a successful fit test with the first respirator tried (Wilkinson et al., 2010). Their testers selected a respirator based on observations of the subject’s facial characteristics, the physical fit of the respirator, and the “real-time” option on the PortaCount® fit tester. Janssen and colleagues (2007) evaluated the workplace protection factor of an N95 filtering face- piece respirator during light, moderate, and heavy intensity tasks in a steel foundry and found a large variability in protection because of re- moving and re-donning the respirator. This may also be a problem in healthcare settings. They suggested that a time-weighted, average workplace protection factor be considered to estimate ongoing protection. Participants at a NIOSH-sponsored workshop (Brosseau, 2009) ex- pressed interest in developing a respirator that did not require initial and annual fit tests and provided suggestions for improving the fit capabili-

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81 DESIGNING AND ENGINEERING EFFECTIVE PPE ties of respirators. Au and colleagues (2010) proposed using a customiz- able, reusable mask with high-efficiency air filters. They investigated the efficacy of this mask without fit testing versus a fit tested N95 respirator in 22 volunteers. The median filtration factor was significantly higher for the N95 respirators compared to the mask that is cut to size. Only 16 of the 22 volunteers had a fit factor greater than 100. This was lower than the pass rate for the N95 (19/22), but was not significantly different. The authors concluded that the customizable mask should be studied further, but that it should not be used without fit testing at this time. Face seal leakage is an important factor in respirator protection, and it depends on several factors, including proper respirator selection, fit, and donning. Cho and colleagues (2010) found that most particle pene- tration occurs through face seal leakage even when the respirator fits well (workplace protection factor = 515), and that particle penetration of the face seal decreases with increases in breathing rate and particle size. Similarly, Grinshpun and colleagues (2009) found that the number of particles penetrating through the facepiece seal far exceeded penetration through the filter medium for both an N95 respirator and a face mask using challenge particles in the 0.03 to 1 µm range. Lee and colleagues (2008c) investigated the protection factor of four N95 respirators and three face masks with a challenge of particles representing bacterial and viral size ranges (aerodynamic size: 0.04 to 1.3 µm). Prior research (Coffey et al., 2004) had demonstrated high protection levels for Respira- tor A and medium protection for Respirator B. Respirators C and D were the same except D had an exhalation valve. Overall, 29 percent of N95 respirators and 100 percent of face masks had protection factors of < 10, the assigned protection factor for the N95 (Lee et al., 2008c). The per- centages of N95 respirators with protection factors of > 10 for all particle sizes tested were 86, 36, 89, and 78 percent for Respirators A to D, re- spectively. There were no significant differences in the protection factor between the N95 and N95 with the exhalation valve. The protection fac- tors of the N95 were an average of 8 to 12 times greater than those of face masks. Particle size–dependent face seal leakage has not been fully investi- gated (Shaffer and Rengasamy, 2009). However, NIOSH has initiated studies to determine whether face seal leakage of nanoparticles is consis- tent with the leakages observed for gases/vapors and larger particles. Further research on leakage of nanoparticles is important to better under- stand the effectiveness of filtering facepiece respirators in workplaces where nanoparticles are present.

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102 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL have been identified. Addressing these issues is important for developing PPE for healthcare personnel that is safe, effective, and comfortable. FINDINGS AND RESEARCH NEEDS This chapter provides an overview of the range of ongoing work on designing and engineering effective PPE to prevent transmission of in- fluenza and other viral respiratory diseases. At its June 2010 workshop and through its literature review, the committee realized that many re- search efforts have been completed recently and that ongoing research efforts in this area continue. The challenge will be to sustain these efforts and to broaden them into areas that will result in wearable and effective PPE for healthcare personnel. Box 3-1 highlights the committee’s find- ings in this area. • Wearability: Respirators: Continue examining the features of N95s, o PAPRs, and elastomeric respirators that impact comfort and tolerability among healthcare personnel. Identify alterations in respirator design and construction that show promise in improving problem features that adversely impact comfort and tolerability. Other PPE: Initiate research to identify factors affecting the o comfort and tolerability of protective eyewear and clothing, and identify changes having the potential to positively influ- ence comfort and tolerability. Evaluate differences between short- and long-term use of PPE as it affects comfort and tol- erability. Develop and field test new designs and features for PPE for healthcare personnel that offer potential for improv- ing comfort and tolerability. • Decontamination and Feasibility of Reuse: Decontamination methods: Continue to assess promising de- o contamination methods for all types of PPE, including re- search on the impact of decontamination methods on respirator protection and on the physical characteristics of

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103 DESIGNING AND ENGINEERING EFFECTIVE PPE BOX 3-1 Findings • Respirators are designed to provide respiratory protection, and respira- tors certified by the National Institute for Occupational Safety and Health are tested to provide effective filtration. Issues remain regarding respira- tor fit, which currently depends on fit testing and user seal checks. Ef- forts focused on addressing total inward leakage may resolve some of these issues, and research on respirators that do not require fit testing is needed. • Face masks and face shields do not provide a tight seal to the wearer’s face. Laboratory research to date on the performance of face masks has focused on inhalable particulates, and there has been little or no re- search as to the performance of these devices on droplet spray. • There is a lack of knowledge as to the performance of eye protection, face shields, gloves and gowns, and other PPE in protecting the wearer from influenza and other respiratory viruses. the respirator (inner, middle, and outer layers). Assess de- contamination effectiveness using either influenza virus or a suitable surrogate. Feasibility of reuse: Develop a protocol for donning and o doffing PPE to minimize self-inoculation. • TIL and Protection: TIL: Finish development of the TIL certification require- o ments for half-mask air-purifying respirators. Assess TIL of very small particles (< 100 nm) with respirators. Face masks and face shields: Assess the TIL of face masks o against droplet spray. Conduct research using manned and unmanned tests to determine if face shields can offer suitable alternative protection to goggles and/or face masks to protect healthcare personnel against droplet spray. Fit: Evaluate the impact of facepiece materials and design on o improving the fit of filtering facepiece respirators. Develop improved and simpler fit testing methods. Examine the ef- fectiveness of performing a user seal check for an N95 respi- rator each time it is donned. Workplace protection studies: Conduct workplace protection o studies to assess protection during typical tasks and time

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104 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL changes in protection. Determine how using typical instru- ments impacts protection, and identify integration issues. • Equipment and Technologies: Integration: Conduct human factors (field of view, visual o acuity, communication) and operational performance studies to assess the ability of healthcare personnel to perform medi- cal procedures in typical healthcare-specific PPE ensembles. New technologies: Continue development of an air-purifying o respirator that specifically addresses the needs of healthcare personnel. New materials and technologies should be devel- oped specifically for filtering facepiece respirators to im- prove fit, comfort, and tolerability. A new low-noise, light- weight, PAPR and a face shield that is reusable and easy to clean should be designed and developed. The efficacy and effectiveness of antiviral-coated PPE and impacts on main- tenance and reuse of PPE should be assessed. RECOMMENDATIONS Recommendation: Continue and Expand Research on PPE for Healthcare Personnel NPPTL and other agencies, private-sector companies, and other organizations should continue to advance research in designing and evaluating the effectiveness of respirator pro- tection for healthcare personnel and expand its research ef- forts to improve and evaluate the effectiveness of gloves, gowns, eye protection, face shields, and face masks in pre- venting the transmission of influenza or other viral respira- tory diseases. Areas of focused research needs include • effectiveness in preventing fomite, droplet spray, or aerosol transmission; • decontamination and feasibility of reuse; • comfort, fit, and usability; • impact on task performance; and • development of technologies specifically for health- care personnel.

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105 DESIGNING AND ENGINEERING EFFECTIVE PPE Recommendation: Improve Fit Test Methods and Evaluate User Seal Checks NPPTL should develop novel, simpler fit test methods and evaluate the effectiveness of performing user seal checks on N95 respirators. Recommendation: Develop and Certify PAPRs for Health- care Personnel NPPTL should develop certification requirements for a low- noise, loose-fitting PAPR for healthcare personnel. Recommendation: Examine the Effectiveness of Face Masks and Face Shields as PPE NPPTL should investigate the effectiveness of face masks and face shields in preventing transmission of viral respiratory diseases. REFERENCES Au, S. S., C. D. Gomersall, P. Leung, and P. T. Li. 2010. A randomised controlled pilot study to compare filtration factor of a novel non-fit-tested high-efficiency particulate air (HEPA) filtering facemask with a fit-tested N95 mask. Journal of Hospital Infection 76(1):23-25. Baig, A. S., C. Knapp, A. E. Eagan, and L. J. Radonovich, Jr. 2010. Health care workers’ views about respirator use and features that should be included in the next generation of respirators. American Journal of Infection Control 38(1):18-25. Bansal, S., P. Harber, D. Yun, D. Liu, Y. Liu, S. Wu, D. Ng, and S. Santiago. 2009. Respirator physiological effects under simulated work conditions. Journal of Occupational and Environmental Hygiene 6(4):221-227. Borkow, G., S. S. Zhou, T. Page, and J. Gabbay. 2010. A novel anti-influenza copper oxide containing respiratory face mask. PLoS ONE 5(6):e11295. Brinker, A., S. A. Gray, and J. Schumacher. 2007. Influence of air-purifying respirators on the simulated first response emergency treatment of CBRN victims. Resuscitation 74(2):310-316. Brosseau, L. M. 2009. Toward better fitting respirators: No fit test respirator workshop and research roadmap, RFQ 2008-Q-10205. http://www.sph. umn.edu/ce/presentations/docs/Final_NoFitRespiratorReport_July28_2009. pdf (accessed November 30, 2010).

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107 DESIGNING AND ENGINEERING EFFECTIVE PPE Eninger, R. M., T. Honda, A. Adhikari, H. Heinonen-Tanski, T. Reponen, and S. A. Grinshpun. 2008a. Filter performance of N99 and N95 facepiece respirators against viruses and ultrafine particles. Annals of Occupational Hygiene 52(5):385-396. Eninger, R. M., T. Honda, T. Reponen, R. McKay, and S. A. Grinshpun. 2008b. What does respirator certification tell us about filtration of ultrafine particles? Journal of Occupational and Environmental Hygiene 5(5):286- 295. Eshbaugh, J. P., P. D. Gardner, A. W. Richardson, and K. C. Hofacre. 2009. N95 and P100 respirator filter efficiency under high constant and cyclic flow. Journal of Occupational and Environmental Hygiene 6(1):52-61. Federal Register. 2009. Notice: Department of Veterans Affairs: Project Better Respiratory Equipment Using Advanced Technologies for Healthcare Employees (B.R.E.A.T.H.E.). http://frwebgate3.access.gpo.gov/cgi-bin/PDF gate.cgi?WAISdocID=ceFTAw/1/2/0&WAISaction=retrieve (accessed No- vember 4, 2010). Fisher, E., and R. Shaffer. 2010. Survival of bacteriophage MS2 on filtering facepiece respirator coupons. Applied Biosafety 15(2):71-76. Fisher, E., S. Rengasamy, D. Viscusi, E. Vo, and R. Shaffer. 2009. Development of a test system to apply virus-containing particles to filtering facepiece respirators for the evaluation of decontamination procedures. Applied and Environmental Microbiology 75(6):1500-1507. Fouchier, R. A. M., P. M. Schneeberger, F. W. Rozendaal, J. M. Broekman, S. A. G. Kemink, V. Munster, T. Kuiken, G. F. Rimmelzwaan, M. Schutten, G. J. J. van Doornum, G. Koch, A. Bosman, M. Koopmans, and A. D. M. E. Osterhaus. 2004. Avian influenza A virus (H7N7) associated with human conjunctivitis and a fatal case of acute respiratory distress syndrome. Proceedings of the National Academy of Sciences (U.S.A.) 101(5):1356- 1361. Fry, D. E., W. E. Harris, E. N. Kohnke, and C. L. Twomey. 2010. Influence of double-gloving on manual dexterity and tactile sensation of surgeons. Journal of the American College of Surgeons 210(3):325-330. Grinshpun, S. A., H. Haruta, R. M. Eninger, T. Reponen, R. T. McKay, and S. A. Lee. 2009. Performance of an N95 filtering facepiece particulate respirator and a surgical mask during human breathing: Two pathways for particle penetration. Journal of Occupational and Environmental Hygiene 6(10):593-603. Hah, S., T. Yuditsky, K. A. Schulz, H. Dorsey, A. R. Deshmukh, and J. Sharra. 2009. Evaluation of human performance while wearing respirators. http://hf.tc.faa.gov/technotes/dot-faa-tc-09-10.pdf (accessed November 3, 2010). Harber, P., S. Bansal, S. Santiago, D. Liu, D. Yun, D. Ng, Y. Liu, and S. Wu. 2009. Multidomain subjective response to respirator use during simulated work. Journal of Occupational and Environmental Medicine 51(1):38-45.

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108 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL Heimbuch, B. K., K. Kinney, B. Nichols, and J. D. Wander. 2009. The dry aerosol deposition device (DADD): An instrument for depositing microbial aerosols onto surfaces. Journal of Microbiological Methods 78(3):255-259. Huang, J. T., and V. I. Huang. 2007. Evaluation of the efficiency of medical masks and the creation of new medical masks. Journal of International Medical Research 35(2):213-223. Hubner, N. O., A. M. Goerdt, N. Stanislawski, O. Assadian, C. D. Heidecke, A. Kramer, and L. I. Partecke. 2010. Bacterial migration through punctured surgical gloves under real surgical conditions. BMC Infectious Diseases 10:192. IOM (Institute of Medicine). 2008. Preparing for an influenza pandemic: Personal protective equipment for healthcare workers. Washington, DC: The National Academies Press. Janssen, L. L., T. J. Nelson, and K. T. Cuta. 2007. Workplace protection factors for an N95 filtering facepiece respirator. Journal of Occupational and Environmental Hygiene 4(9):698-707. Johnson, A. T., F. C. Koh, S. Jamshidi, and T. E. Rehak. 2008. Human subject testing of leakage in a loose-fitting papr. Journal of Occupational and Environmental Hygiene 5(5):325-329. Johnson, D. F., J. D. Druce, C. Birch, and M. L. Grayson. 2009. A quantitative assessment of the efficacy of surgical and N95 masks to filter influenza virus in patients with acute influenza infection. Clinical Infectious Diseases 49(2):275-277. Jones, C., B. Brooker, and M. Genon. 2010. Comparison of open and closed staff-assisted glove donning on the nature of surgical glove cuff contamination. Australian and New Zealand Journal of Surgery 80(3):174- 177. Korniewicz, D. M., and M. El Masri. 2007. Effect of aloe-vera impregnated gloves on hand hygiene attitudes of health care workers. MEDSURG Nursing 16(4):247-252. Laing, R. M. 2008. Protection provided by clothing and textiles against potential hazards in the operating theatre. International Journal of Occupational and Safety Ergonomics 14(1):107-115. Lee, J. H., C. Y. Wu, K. M. Wysocki, S. Farrah, and J. Wander. 2008a. Efficacy of iodine-treated biocidal filter media against bacterial spore aerosols. Journal of Applied Microbiology 105(5):1318-1326. Lee, J. H., C. Y. Wu, C. N. Lee, D. Anwar, K. M. Wysocki, D. A. Lundgren, S. Farrah, J. Wander, and B. K. Heimbuch. 2009. Assessment of iodine-treated filter media for removal and inactivation of MS2 bacteriophage aerosols. Journal of Applied Microbiology 107(6):1912-1923. Lee, M. C., S. Takaya, R. Long, and A. M. Joffe. 2008b. Respirator-fit testing: Does it ensure the protection of healthcare workers against respirable particles carrying pathogens? Infection Control and Hospital Epidemiology 29(12):1149-1156.

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109 DESIGNING AND ENGINEERING EFFECTIVE PPE Lee, S. A., S. A. Grinshpun, and T. Reponen. 2008c. Respiratory performance offered by N95 respirators and surgical masks: Human subject evaluation with NaCl aerosol representing bacterial and viral particle size range. Annals of Occupational Hygiene 52(3):177-185. Li, Y., T. Wong, J. Chung, Y. P. Guo, J. Y. Hu, Y. T. Guan, L. Yao, Q. W. Song, and E. Newton. 2006. In vivo protective performance of N95 respirator and surgical facemask. American Journal of Industrial Medicine 49(12):1056-1065. Manian, F. A., and J. J. Ponzillo. 2007. Compliance with routine use of gowns by healthcare workers (HCWs) and non-HCW visitors on entry into the rooms of patients under contact precautions. Infection Control and Hospital Epidemiology 28(3):337-340. Mansour, A. A., 3rd, J. L. Even, S. Phillips, and J. L. Halpern. 2009. Eye protection in orthopaedic surgery. An in vitro study of various forms of eye protection and their effectiveness. Journal of Bone and Joint Surgery 91(5):1050-1054. McMahon, E., K. Wada, and A. Dufresne. 2008. Implementing fit testing for N95 filtering facepiece respirators: Practical information from a large cohort of hospital workers. American Journal of Infection Control 36(4):298-300. Mendel, L. L., J. A. Gardino, and S. R. Atcherson. 2008. Speech understanding using surgical masks: A problem in health care? Journal of the American Academy of Audiology 19(9):686-695. Monaghan, W. D., M. R. Roberge, M. Rengasamy, and R. J. Roberge. 2009. Thermal imaging comparison of maximum surface temperatures achieved on N95 filtering facepiece respirators with and without exhalation valves at sedentary breathing volumes. Journal of the International Society for Respiratory Protection 26:12-19. Newman, J. B., M. Bullock, and R. Goyal. 2007. Comparison of glove donning techniques for the likelihood of gown contamination. An infection control study. Acta Orthopaedica Belgica 73(6):765-771. Oberg, T., and L. M. Brosseau. 2008. Surgical mask filter and fit performance. American Journal of Infection Control 36(4):276-282. Oestenstad, R. K., and A. A. Bartolucci. 2010. Factors affecting the location and shape of face seal leak sites on half-mask respirators. Journal of Occupational and Environmental Hygiene 7(6):332-341. Oestenstad, R. K., L. J. Elliott, and T. M. Beasley. 2007. The effect of gender and respirator brand on the association of respirator fit with facial dimensions. Journal of Occupational and Environmental Hygiene 4(12):923-930. Oxford, J. S., R. Lambkin, M. Guralnik, R. A. Rosenbloom, M. P. Petteruti, K. Digian, and C. Lefante. 2007. Preclinical in vitro activity of QR-435 against influenza A virus as a virucide and in paper masks for prevention of viral transmission. American Journal of Therapeutics 14(5):455-461.

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110 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL Partecke, L. I., A. M. Goerdt, I. Langner, B. Jaeger, O. Assadian, C. D. Heidecke, A. Kramer, and N. O. Huebner. 2009. Incidence of microperforation for surgical gloves depends on duration of wear. Infection Control and Hospital Epidemiology 30(5):409-414. Radonovich, L. J., Jr., J. Cheng, B. V. Shenal, M. Hodgson, and B. S. Bender. 2009. Respirator tolerance in health care workers. Journal of the American Medical Association 301(1):36-38. Radonovich, L. J., Jr., R. Yanke, J. Cheng, and B. Bender. 2010. Diminished speech intelligibility associated with certain types of respirators worn by healthcare workers. Journal of Occupational and Environmental Hygiene 7(1):63-70. Reinertsen, R. E., H. Faerevik, K. Holbo, R. Nesbakken, J. Reitan, A. Royset, and M. Suong Le Thi. 2008. Optimizing the performance of phase-change materials in personal protective clothing systems. International Journal of Occupational Safety and Ergonomics 14(1):43-53. Rengasamy, S., W. P. King, B. C. Eimer, and R. E. Shaffer. 2008. Filtration performance of NIOSH-approved N95 and P100 filtering facepiece respirators against 4 to 30 nanometer-size nanoparticles. Journal of Occupational and Environmental Hygiene 5(9):556-564. Rengasamy, S., B. C. Eimer, and R. E. Shaffer. 2009. Comparison of nanoparticle filtration performance of NIOSH-approved and CE-marked particulate filtering facepiece respirators. Annals of Occupational Hygiene 53(2):117-128. Rengasamy, S., B. Eimer, and R. E. Shaffer. 2010a. Simple respiratory protection—evaluation of the filtration performance of cloth masks and common fabric materials against 20-1000 nm size particles. Annals of Occupational Hygiene 54(7):789-798. Rengasamy, S., E. Fisher, and R. E. Shaffer. 2010b. Evaluation of the survivability of MS2 viral aerosols deposited on filtering face piece respirator samples incorporating antimicrobial technologies. American Journal of Infection Control 38(1):9-17. Rissanen, S., I. Jousela, J. R. Jeong, and H. Rintamaki. 2008. Heat stress and bulkiness of chemical protective clothing impair performance of medical personnel in basic lifesaving tasks. Ergonomics 51(7):1011-1022. Roberge, M. R., M. R. Vojtko, R. J. Roberge, R. J. Vojtko, and D. P. Landsittel. 2008. Wearing an N95 respirator concurrently with a powered air-purifying respirator: Effect on protection factor. Respiratory Care 53(12):1685-1690. Roberge, R. J. 2008. Evaluation of the rationale for concurrent use of N95 filtering facepiece respirators with loose-fitting powered air-purifying respirators during aerosol-generating medical procedures. American Journal of Infection Control 36(2):135-141. ———. 2009. Physiological burden associated with the use of filtering facepiece respirators (N95 masks) during pregnancy. Journal of Women’s Health 18(6):819-826.

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111 DESIGNING AND ENGINEERING EFFECTIVE PPE Roberge, R. J., A. Coca, W. J. Williams, A. J. Palmiero, and J. B. Powell. 2010a. Surgical mask placement over N95 filtering facepiece respirators: Physiological effects on healthcare workers. Respirology 15(3):516-521. Roberge, R. J., A. Coca, W. J. Williams, J. B. Powell, and A. J. Palmiero. 2010b. Physiological impact of the N95 filtering facepiece respirator on healthcare workers. Respiratory Care 55(5):569-577. ———. 2010c. Reusable elastomeric air-purifying respirators: Physiologic impact on health care workers. American Journal of Infection Control 38(5):381-386. Salter, W. B., K. Kinney, W. H. Wallace, A. E. Lumley, B. K. Heimbuch, and J. D. Wander. 2010. Analysis of residual chemicals on filtering facepiece respirators after decontamination. Journal of Occupational and Environmental Hygiene 7(8):437-445. Schumacher, J., J. Runte, A. Brinker, K. Prior, M. Heringlake, and W. Eichler. 2008. Respiratory protection during high-fidelity simulated resuscitation of casualties contaminated with chemical warfare agents. Anaesthesia 63(6):593-598. Schumacher, J., S. A. Gray, L. Weidelt, A. Brinker, K. Prior, and W. M. Stratling. 2009. Comparison of powered and conventional air-purifying respirators during simulated resuscitation of casualties contaminated with hazardous substances. Emergency Medicine Journal 26(7):501-505. Shaffer, R., and S. Rengasamy. 2009. Respiratory protection against airborne nanoparticles: A review. Journal of Nanoparticle Research 11(7):1661-1672. Tang, J. W., T. J. Liebner, B. A. Craven, and G. S. Settles. 2009. A schlieren optical study of the human cough with and without wearing masks for aerosol infection control. Journal of the Royal Society Interface 6(Suppl. 6):S727-S736. Udayasiri, R., J. Knott, D. T. D. Mc, J. Papson, F. Leow, and F. A. Hassan. 2007. Emergency department staff can effectively resuscitate in level C personal protective equipment. Emergency Medicine in Australasia 19(2):113-121. Viscusi, D., W. King, and R. Shaffer. 2007. Effect of decontamination on the filtration efficiency of two FFR models. Journal of the International Society for Respiratory Protection 24:93-107. Viscusi, D. J., M. Bergman, E. Sinkule, and R. E. Shaffer. 2009a. Evaluation of the filtration performance of 21 N95 filtering face piece respirators after prolonged storage. American Journal of Infection Control 37(5):381-386. Viscusi, D. J., M. S. Bergman, B. C. Eimer, and R. E. Shaffer. 2009b. Evaluation of five decontamination methods for filtering facepiece respirators. Annals of Occupational Hygiene 53(8):815-827. Vo, E., S. Rengasamy, and R. Shaffer. 2009. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Applied and Environmental Microbiology 75(23):7303-7309.

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112 PERSONAL PROTECTIVE EQUIPMENT FOR HEALTHCARE PERSONNEL Vojtko, M. R., M. R. Roberge, R. J. Vojtko, R. J. Roberge, and D. P. Landsittel. 2008. Effect on breathing resistance of a surgical mask worn over a N95 filtering facepiece respirator. Journal of the International Society for Respiratory Protection 25:1-8. Wander, J., and B. Heimbuch. 2009. Challenge of N95 and P100 filtering facepiece respirators with particle containing viable H1N1. Pittsburgh, PA: National Institute for Occupational Safety and Health. Watson, C. M., M. C. McCrory, J. M. Duval-Arnould, and E. A. Hunt. 2009. Abstract P212: Simulated pediatric resuscitation during novel H1N1 influenza outbreak. Circulation 120:S1487-S1488. Watson, L., W. Sault, R. Gwyn, and P. R. Verbeek. 2008. The “delay effect” of donning a gown during cardiopulmonary resuscitation in a simulation model. Canadian Journal of Emergency Medical Care 10(4):333-338. Wilkinson, I. J., D. Pisaniello, J. Ahmad, and S. Edwards. 2010. Evaluation of a large-scale quantitative respirator-fit testing program for healthcare workers: Survey results. Infection Control and Hospital Epidemiology 31(9):918-925. Wilson, J. A., H. P. Loveday, P. N. Hoffman, and R. J. Pratt. 2007. Uniform: An evidence review of the microbiological significance of uniforms and uniform policy in the prevention and control of healthcare-associated infections. Report to the Department of Health (England). Journal of Hospital Infection 66(4):301-307. Wines, M. P., A. Lamb, A. N. Argyropoulos, A. Caviezel, C. Gannicliffe, and D. Tolley. 2008. Blood splash injury: An underestimated risk in endourology. Journal of Endourology 22(6):1183-1187. Winter, S., J. H. Thomas, D. P. Stephens, and J. S. Davis. 2010. Particulate face masks for protection against airborne pathogens—one size does not fit all: An observational study. Critical Care and Resuscitation 12(1):24-27. Zhuang, Z., B. Bradtmiller, and R. E. Shaffer. 2007. New respirator fit test panels representing the current U.S. civilian work force. Journal of Occupational and Environmental Hygiene 4(9):647-659. Zhuang, Z., D. Groce, H. W. Ahlers, W. Iskander, D. Landsittel, S. Guffey, S. Benson, D. Viscusi, and R. E. Shaffer. 2008. Correlation between respirator fit and respirator fit test panel cells by respirator size. Journal of Occupational and Environmental Hygiene 5(10):617-628.