Face mask fit hacks: Improving the fit of KN95 masks and surgical masks with fit alteration techniques

Abstract

Introduction During the course of the COVID-19 pandemic, there have been suggestions that various techniques could be employed to improve the fit and, therefore, the effectiveness of face masks. It is well recognized that improving fit tends to improve mask effectiveness, but whether these fit modifiers are reliable remains unexplored. In this study, we assess a range of common “fit hacks” to determine their ability to improve mask performance. Methods Between July and September 2020, qualitative fit testing was performed in an indoor living space. We used quantitative fit testing to assess the fit of both surgical masks and KN95 masks, with and without ‘fit hacks’, on four participants. Seven fit hacks were evaluated to assess impact on fit. Additionally, one participant applied each fit hack multiple times to assess how reliable hacks were when reapplied. A convenience of four participants took part in the study, three females and one male with a head circumference range of 54 to 60 centimetres. Results and discussion The use of pantyhose, tape, and rubber bands were effective for most participants. A pantyhose overlayer was observed to be the most effective hack. High degrees of variation were noted between participants. However, little variation was noted within participants, with hacks generally showing similar benefit each time they were applied on a single participant. An inspection of the fit hacks once applied showed that individual facial features may have a significant impact on fit, especially the nose bridge. Conclusions Fit hacks can be used to effectively improve the fit of surgical and KN95 masks, enhancing the protection provided to the wearer. However, many of the most effective hacks are very uncomfortable and unlikely to be tolerated for extended periods of time. The development of effective fit-improvement solutions remains a critical issue in need of further development.

Automated Adjustment of PPE Masks Using IoT Sensor Fusion

“…There are two accepted methods for assessing the fitness of a mask [ 17 ]. The first is a quantitative fit test that uses a machine to check for leakage around the face seal.…”

“…There are methods to improve the fit of face masks. Tape can be used to cover the edges of masks to improve the seal [ 17 ]. It also states that the high filtration material masks used with proper fit provide the best protection to the user.…”

“…The only drawback is that after achieving a better fit, comfort is lost to the user, which is again an important factor. In a nutshell, better filtration, proper fitting of the mask, and comfort cannot be achieved simultaneously; out of three, one is compromised at all times [ 13 , 14 , 15 , 16 , 17 ]. This shows the high need for a technology that can inculcate all three behaviors in one.…”

The use of fibrous face masks as a barrier against infectious biological airborne particles

“…3 Mannequins are used to study face mask fit and leakages around the edges of the mask. 34,35,37 Face is covered with a mask and a pipe from the mannequin is connected to a respiratory pump to simulate breathing. 36

Figure 5.Surgical and Respirator masks fit [Reprinted with permission from reference number].

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Experimental Measurement of the Size of Gaps Required to Compromise Fit of an N95 Respirator

“…While it has been noted that improved fit of surgical masks and fabric face coverings augments their performance, the fit of these masks is typically poor and so they are not included in this study. 18 As we were not measuring the impact of facial dimensions on fit, our study was limited to a small pool of participants.…”