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. 2021 Aug 17;22(5):1045-1050.
doi: 10.5811/westjem.2021.3.50516.

Efficacy of Various Facial Protective Equipment for Infection Control in a Healthcare Setting

Jessica Dinsmore  1 , Susan Brands  1 , Steven Perry  1 , Michael Lopez  1 , Yutong Dong  1 , Daniel Palasz  1 , Jennifer Tucker  1
Affiliations

Efficacy of Various Facial Protective Equipment for Infection Control in a Healthcare Setting

Jessica Dinsmore et al. West J Emerg Med. .

Abstract

Introduction: The coronavirus 2019 (COVID-19) pandemic has reinforced the importance of facial protection against droplet transmission of diseases. Healthcare workers wear personal protection equipment (PPE), including face shields and masks. Plastic face shields may have advantages over regular medical masks. Although many designs of face shields exist, there is a paucity of evidence regarding the efficacy of shield designs against droplet transmissions. There is even less published evidence comparing various face shields. Due to the urgency of the pandemic and the health and safety of healthcare workers, we aimed to study the efficacy of various face shields against droplet transmission.

Methods: We simulated droplet transmission via coughing using a heavy-duty chemical spray bottle filled with fluorescein. A standard-adult sized mannequin head was used. The mannequin head wore various face shields and was positioned to face the spray bottle at either a 0°, 45°, or 90° angle. The spray bottle was positioned at and sprayed from 30 centimeters (cm), 60 cm, or 90 cm away from the head. These steps were repeated for all face shields used. Control was a mannequin that wore no PPE. A basic mask was also tested. We collected data for particle count, total area of particle distribution, average particle size, and percentage area covered by particles. We analyzed percent covered by particles using a repeated measures mixed-model regression with Tukey-Kramer pairwise comparison.

Results: We used least square means to estimate the percentage area covered by particles. Wearing PPE regardless of the design reduced particle transmission to the mannequin compared to the control. The LCG mask had the lowest square means of 0.06 of all face-shield designs analyzed. Tukey-Kramer pairwise comparison showed that all PPEs had a decrease in particle contamination compared to the control. LCG shield was found to have the least contamination compared to all other masks (P < 0.05).

Conclusion: Results suggest the importance of wearing a protective covering against droplet transmission. The LCG shield was found to decrease facial contamination by droplets the most of any tested protective equipment.

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Conflict of interest statement

Conflicts of Interest: By the WestJEM article submission agreement, all authors are required to disclose all affiliations, funding sources and financial or management relationships that could be perceived as potential sources of bias. No author has professional or financial relationships with any companies that are relevant to this study. There are no conflicts of interest or sources of funding to declare.

Figures

Figure 1
Figure 1
Particle distribution sizes for 30 centimeters spray in micrometers squared. StdDev, standard deviation; min, minimum.
Figure 2
Figure 2
Particle distribution sizes for 60 centimeters spray in micrometers squared. StdDev, standard deviation; min, minimum.
Figure 3
Figure 3
Particle distribution sizes for 90 centimeters spray in micrometers squared. StdDev, standard deviation; min, minimum.
See this image and copyright information in PMC

References

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MeSH terms