Particle filtration efficiency of respirators during the COVID-19 pandemic

Background: Respirators are an essential medical device vital to prevent the transmission of airborne illness between persons. This study presents an investigation conducted by the Therapeutic Goods Administration (TGA) into the particle filtration efficiency (PFE) performance of respirators supplied in Australia that were included as medical devices in the Australian Register of Therapeutic Goods (ARTG) throughout the COVID-19 pandemic or supplied to the TGA from other jurisdictions for compliance testing. Methods: A total of 400 real-world batches of respirators were tested against a rapid-screen PFE method developed by the TGA. The TGA analysed a respirator's ability to meet its claimed filtration efficiency with a statistical power analysis differentiated by the claimed PFE standard, country of manufacture, time of inclusion into the ARTG and respirators with surgical against non-surgical claims. Findings: Of the tested batches of respirators (n = 400), 70 % were compliant with the pre-set compliance criteria. The results indicate statistically significant PFE differences (p < 0.05) between respirators claiming the standards 42 CFR Part 84, AS 1716:2012, GB 19083: 2010 and EN 149:2001+ A1:2009 when tested against respirators claiming GB 2626:2006. There were no observed significant differences between the PFE of surgical and non-surgical respirators (p > 0.05). Interpretation: The findings of this study highlight the importance of ensuring respirators meet their claimed PFE level based on their claimed standard prior to manufacturer release. Further studies should be focussed on investigating the effect of respiratory protection devices and their claimed efficiency in clinical settings such as hospitals against aerosolised particulates using a range of respiratory protection devices.