Performance Comparison of N95 and P100 Filtering Facepiece Respirators with Presence of Artificial Leakage

Jintuo Zhu; Xinjian He; Steve Guffey; Liang Wang; Haifeng Wang; Jianwei Cheng

doi:10.1093/annweh/wxz086

Performance Comparison of N95 and P100 Filtering Facepiece Respirators with Presence of Artificial Leakage

Ann Work Expo Health. 2020 Feb 20;64(2):202-216. doi: 10.1093/annweh/wxz086.

Authors

Jintuo Zhu^{1

2

3}, Xinjian He⁴, Steve Guffey⁴, Liang Wang^{1

3}, Haifeng Wang^{1

2

3}, Jianwei Cheng^{1

3}

Affiliations

¹ Key Laboratory of Gas and Fire Control for Coal Mines (China University of Mining and Technology), Ministry of Education, Xuzhou, Jiangsu, China.
² National Professional Laboratory for Fundamental Research of Mine Gas and Dust Control Technology, School of Safety Engineering, China University of Mining and Technology, Xuzhou, Jiangsu, China.
³ School of Safety Engineering, China University of Mining and Technology, Xuzhou, Jiangsu, China.
⁴ Department of Industrial and Management Systems Engineering, Statler College of Engineering and Mineral Resources, West Virginia University, Morgantown, WV, USA.

PMID: 31785204
DOI: 10.1093/annweh/wxz086

Abstract

Objectives: National Institute for Occupational Safety and Health-approved P100 filtering facepiece respirators (FFRs) have a higher filter efficiency compared to the N95 filters. However, the former typically produce higher flow resistance (Rf). Consequently, when faceseal leakage is present, the proportion of leakage airflow for P100 FFRs may exceed that of N95s, resulting in a higher total inward leakage (TIL) of the P100.

Methods: In this manikin-based study, the performance of two pairs of N95 and P100 FFRs (N95-A versus P100-A; N95-B versus P100-B) were compared under five sealing conditions (fully sealed and partially sealed with one, two, or three leaks of 0.8-mm, and one 2-mm leak). Sodium chloride particles (CMD ~45 nm) were used as the challenge aerosol. Respirators were tested under three constant flows (15, 50, and 85 L/min) and three cyclic flows (mean inspiratory flow = 15, 50, and 85 L/min). Both filter penetration (Pfilter) and TIL were determined. The Rf under constant flows was recorded. Based on Pfilter, TIL, and Rf, the quality factor (qf) was calculated to compare the overall performance of N95 and P100 FFRs.

Results: For a fully sealed condition, the Pfilter was much lower for the P100 FFRs than for the N95 FFRs. When small leaks were inserted (0.8-mm and 2 × 0.8-mm), the TIL was higher for the P100 FFRs than for the N95 FFRs under the lowest tested flow (15 L/min), while for greater leaks (3 × 0.8-mm and 2-mm), the TIL of the P100 FFRs was always higher regardless of the flow. The Rf of P100 FFRs was measured twice as high as the N95. The qf values were also found higher for the N95 FFRs than for the P100 FFRs regardless of leak size and breathing flow.

Conclusions: With the presence of artificial leakage, a P100 FFR with high-flow-resistance may not be as protective as a low-flow-resistance N95 FFR. This finding suggests that future efforts should be directed to reducing the breathing resistance when designing P100 FFRs.

Keywords: N95; P100; breathing resistance; faceseal leakage; filter penetration; quality factor; respirator; total inward leakage.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants, Occupational / analysis
Equipment Design
Filtration
Humans
Occupational Exposure
Particle Size
Respiratory Protective Devices*
Ventilators, Mechanical

Substances

Air Pollutants, Occupational