Assessing the quality of nontraditional N95 filtering face-piece respirators available during the COVID-19 pandemic

Abstract

Background: During the current COVID-19 pandemic, supply chains for Personal Protective Equipment (PPE) have been severely disrupted and many products, particularly surgical N95 filtering facepiece respirators (FFRs; "masks") are in short supply. As a consequence, an Emergency Use Authorization (EUA) from the FDA has allowed importation of N95-type masks manufactured to international standards; these include KN95 masks from China and FFP2 masks from the European Union. Methods: We conducted a survey of mask in the inventory of major academic medical centers in Boston, MA to determine provenance and manufacturer. We then assembled a simple apparatus for performing a necessary (but not sufficient) test of filtration performance and tested masks from the inventory; an accompanying website shows how to build and use the testing apparatus. Results: Our survey showed that, seven months after the start of the COVID-19 pandemic, over 100 different makes and models of N95-type masks are in the inventory of local hospitals as opposed to 2-5 models under normal circumstances. A substantial number of unfamiliar masks are from unknown manufacturers. Many did not perform to accepted standards and are likely to be counterfeit. Due to the absence of publicly available information on mask suppliers in the FDA EUA and confusing or inconsistent labeling of KN95 masks, it is difficult to distinguish legitimate and counterfeit products. Conclusions: Many of the FFR masks available for procurement during the COVID-19 pandemic do not provide levels of fit and filtration similar to those of N95 masks and are not acceptable for use in healthcare settings. Based on these results, and in consultation with occupational health officers, we make six recommendations for end users to assist in acquiring legitimate products. In particular, institutions should always assess masks from non-traditional supply chains by checking their markings and manufacturer information against data provided by NIOSH and the latest FDA EUA Appendix A. In the absence of verifiable information on the legitimacy of mask source, institutions should consider measuring mask fit and filtration directly. We also make suggestions for U.S and Chinese regulatory agencies with regard to labeling and public disclosure aimed at increase pandemic resilience.

KN95 filtering facepiece respirators distributed in South Africa fail safety testing protocols

“…Some KN95 masks, although filtration integrity was of adequate standard, therefore still failed on facial seal and inward leakage of particles. Plana et al [8] (non-peer reviewed data in preprint format) also found that several KN95 masks failed to meet mask filter integrity thresholds. Their article highlighted that a high proportion of KN95 masks may be counterfeit.…”

“…The most commonly available substitute for the N95 mask has been the KN95 mask, which is mainly manufactured in China to the GB2626-2006 standard, and which is considered equivalent to the N95 by the US Food And Drug Administration (FDA) following Emergency Use Authorisation based on testing of filtration efficacy of the mask material. [8] The manufacture of N95-like masks remains highly regulated in order to ensure that they filter out at least 95% of penetrating aerosol particles ≥0.3 µm in diameter, fit tightly to maximise the passage of inhaled air through the filter fabric of the mask, and have low inhalational resistance to minimise breathing difficulty. There has been a growing concern about the quality of the circulating supplies of N95-like masks in many parts of the world, including the circulation of counterfeit masks.…”

“…Modification of the KN95 ear-loop tension using head straps or staples, or improving the facial seal using Micropore tape, enhanced (8,9). The nebuliser cup (11) was filled with 0.9% saline solution.…”

“…[22] Such sites also highlight clues to counterfeit masks that do not meet safety requirements, including lack of manufacturer and distributor information, the presence of ear loops, perforation in the mask material, lack of labelling on the mask certifying that it is approved, and embossing on KN95s that exposes the underlying filter layer. [8]…”

A Crisis-Responsive Framework for Medical Device Development during the COVID-19 Pandemic

“…To avoid forgetting the lessons of COVID-19 pandemic, it is essential that innovative designs and approaches be further developed, tested, and integrated into normal regulatory chains so they are ready for future emergencies. Changes in regulatory policies would also enable a middle ground, balancing the rigidity of the pre-crisis approach with the free-for-all and counterfeiting 80 unintentionally enabled by EUAs. We envision the development of open-source repositories, such as NIH 3D Print Exchange, to facilitate independent testing of products to meet key NIOSH, FDA and other requirements for functionality and safety.…”