Comparison of Performance of Three Different Types of Respiratory Protection Devices

Abstract

Respiratory protection is offered to American workers in a variety of ways to guard against potential inhalation hazards. Two of the most common ways are elastomeric N95 respirators and N95 filtering-facepiece respirators. Some in the health care industry feel that surgical masks provide an acceptable level of protection in certain situations against particular hazards. This study compared the performance of these types of respiratory protection during a simulated workplace test that measured both filter penetration and face-seal leakage. A panel of 25 test subjects with varying face sizes tested 15 models of elastomeric N95 respirators, 15 models of N95 filtering-facepiece respirators, and 6 models of surgical masks. Simulated workplace testing was conducted using a TSI PORTACOUNT Plus model 8020, and consisted of a series of seven exercises. Six simulated workplace tests were performed with redonning of the respirator/mask occurring between each test. The results of these tests produced a simulated workplace protection factor (SWPF). The geometric mean (GM) and the 5th percentile values of the SWPFs were computed by category of respiratory protection using the six overall SWPF values. The level of protection provided by each of the three respiratory protection types was compared. The GM and 5th percentile SWPF values without fit testing were used for the comparison, as surgical masks were not intended to be fit tested. The GM values were 36 for elastomeric N95 respirators, 21 for N95 filtering-facepiece respirators, and 3 for surgical masks. An analysis of variance demonstrated a statistically significant difference between all three. Elastomeric N95 respirators had the highest 5th percentile SWPF of 7. N95 filtering-facepiece respirators and surgical masks had 5th percentile SWPFs of 3 and 1, respectively. A Fisher Exact Test revealed that the 5th percentile SWPFs for all three types of respiratory protection were statistically different. In addition, both qualitative (Bitrex and saccharin) and quantitative (N95-Companion) fit testing were performed on the N95 filtering- and elastomeric-facepiece respirators. It was found that passing a fit test generally improves the protection afforded the wearer. Passing the Bitrex fit test resulted in 5th percentile SWPFs of 11.1 and 7.9 for elastomeric and filtering-facepiece respirators, respectively. After passing the saccharin tests, the elastomeric respirators provided a 5th percentile of 11.7, and the filtering-facepiece respirators provided a 5th percentile of 11.0. The 5th percentiles after passing the N95-Companion were 13.0 for the elastomeric respirators and 20.5 for the filtering-facepiece respirators. The data supports fit testing as an essential element of a complete respiratory protection program.

Dispersion and Exposure to a Cough-Generated Aerosol in a Simulated Medical Examination Room

“…(4) Further, when surgical masks are actually worn by workers, the protection offered by these devices is reduced even more due to face seal leaks that tend to form around the edges of the mask. (5,31,32) On the other hand, our results show that N95 FFRs can protect a worker from the high aerosol concentration within a cough plume impinging directly on the worker, and the steady-state aerosol that accumulates as the cough aerosol spreads throughout the room. This is true even if the worker is respiring heavily.…”

Prevention of nosocomial transmission of extensively drug-resistant tuberculosis in rural South African district hospitals: an epidemiological modelling study

“…Respiratory protection: The efficiency of an N95 respirators is 95%, with a real-world face-seal leakage rate of 0-39% [8,[47][48][49][50]. Adherence ranges between 44% and 97% [51][52][53].…”

“…We also compared the efficacy of staff respirators to the estimated efficacy of additionally having patients use less effective barriers such as inexpensive surgical masks and handkerchiefs. These barriers have a leakage rate sampled from a triangular distribution from 0 to 100% with mode 20%, and an efficiency sampled from a triangular distribution with mode 50% (range 0% to 75%) [8,50,[54][55][56][57]. When an enforcement nurse was added to the ward, we estimated adherence to shift to a uniform 70 to 100% distribution for both staff and patients [58].…”

Analysis of Problem Awareness in Hygiene Mask Wearers: A Cross-Sectional Survey

“…The percentages of problem reporting, from the aggregated results of question (4), are shown in Figure 3. This figure also shows the percentages for the number of intended uses.…”

“…Industrial masks are for protection against gas, vapor, or dust from corrosive or harmful substances in industrial plants and workplaces [4]. Surgical masks are used to guard medical staff from infection in clinical practice [5].…”