Assessment of a Novel Low-Cost Personal Respirator Evaluation Device
Quinton F. Burke M. Eng.*, Kevin Aroom M.S., P.E., and Martha O. Wang Ph.D.
Robert E. Fischell Institute for Biomedical Devices, 5102A A. James Clark Hall, 8278 Paint Branch Drive, University of Maryland, College Park, MD 20742
Background: Throughout the COVID-19 pandemic, respirators and masks have been recommended, and in many instances mandated, across the globe. The National Institute for Occupational Safety and Health (NIOSH) is the main regulatory agency for respirators in the United States. Currently, the TSI 8130A and the ATI 100Xs machines are utilized for respirator filtration and resistance testing, but both are costly and valued upwards of U.S. $100,000.
Objective: The goal of this study was to develop a low-cost respirator evaluation mechanism (LREM) to evaluate respirators as well as masks and other materials for filtration efficiency (FE), inhalation resistance (IR), and exhalation resistance (ER). The aim of this mechanism is to support the development of innovative and alternative respirator and mask designs and materials with an inexpensive and more accessible testing device.
Methods: The methods and design for the LREM were based on U.S. 42 CFR Part 84 Subpart K and the corresponding standard testing procedures for air-purifying respirators published by NIOSH. The LREM itself is constructed from available components and functions to deliver sodium chloride (NaCl) aerosols in a stream of airflow to challenge a respirator or mask sample. A variety of respirators, masks, and materials were tested on both the LREM and an ATI 100Xs to assess how the LREM compares to one of the current evaluation devices.
Results: Overall, the LREM offers promise as an accessible and low-cost testing option. The LREM can accurately determine the pass/fail status of the N95 filtering facepiece respirators (FFRs) samples tested for both IR and FE based on NIOSH criteria. For all respirators, masks, and materials tested, the LREM and ATI 100Xs both show similar performance trends as seen by rankings of sample performance.
Conclusions: The LREM was constructed for approximately 6% the cost of current respirator testing gold standards. The LREM could serve as a first pass testing method done before official respirator testing (e.g. per NIOSH mandated testing) and can be particularly useful in the development of innovative respirators and masks or in testing alternative materials for each.
Keywords: COVID-19, respirator, mask, respirator testing, filtration efficiency, inhalation resistance, exhalation resistance.