Experimental Efficacy of the Face Shield and the Mask against Emitted and Potentially Received Particles

Wendling, Jean-Michel; Fabacher, Thibaut; Pébaÿ, Philippe Pierre; Cosperec, Isabelle; Rochoy, Michaël

doi:10.3390/ijerph18041942

Cited by 28 publications

(30 citation statements)

References 52 publications

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“…This suggests that wearing a face shield can provide some protection from cough droplets to those standing directly in front of the wearer. This was consistent with the findings from previous studies (Pan et al 2020 andWendling et al 2021).…”

Section: Discussionsupporting

confidence: 94%

Evaluation of Face Shields, Goggles and Safety Glasses as a Virus Transmission Control Measure to Protect the Wearer Against Cough Droplets

Hall¹,

Johnson²,

Bailey³

et al. 2022

Preprint

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Face shields (also referred to as visors), goggles and safety glasses have been worn during the COVID-19 pandemic as one measure to control transmission of the virus. However, their effectiveness in controlling facial exposure to cough droplets is not well established and standard tests for evaluating eye protection for this application are limited. A method was developed to evaluate face shields, goggles and safety glasses as a control measure to protect the wearer against cough droplets. The method uses a semi-quantitative assessment of facial droplet deposition. A cough simulator was developed to generate droplets comparable to those from a human cough. The droplets consisted of a UV fluorescent marker (fluorescein) in water. Fourteen face shields, four pairs of goggles and one pair of safety glasses were evaluated by mounting them on two different sizes of breathing manikin head and challenging them with the simulated cough. The manikin head was positioned in seven orientations relative to the cough simulator to represent various potential occupational exposure scenarios, for example, a nurse standing over a patient. Droplet deposition in the eyes, nose and mouth regions were visualised following three ‘coughs’. Face shields, goggles and safety glasses reduced, but did not eliminate exposure to the wearer from droplets such as those produced by a human cough. The level of protection differed based on the design of the personal protective equipment and the relative orientation of the wearer to the cough. For example, face shields and goggles offered the greatest protection when a cough challenge was face on or from above and the least protection when a cough challenge was from below. Face shields were also evaluated as source control to protect others from the wearer. Results suggested that if a coughing person wears a face shield, it can provide some protection from cough droplets to those standing directly in front of the wearer.

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Section: Discussionsupporting

confidence: 94%

Evaluation of Face Shields, Goggles and Safety Glasses as a Virus Transmission Control Measure to Protect the Wearer Against Cough Droplets

Hall¹,

Johnson²,

Bailey³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…0.14 µm for SARS-CoV-2) [13,[25][26][27]. Face masks serve to reduce the number of particles, especially heavier ones [17,28,29]. Considering this, more attention should be paid to small particle sizes (diameter < 1 µm) when indoor viral aerosol dispersion is discussed.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Aerosol and CO2 Dispersion for Evaluation of COVID-19 Infection Risk in a Concert Hall

Schade

Reimer

Seipenbusch³

et al. 2021

IJERPH

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The dispersion of small aerosols in a concert hall is experimentally studied for estimating the risk of infection with SARS-CoV-2 during a concert. A mannequin was modified to emit an air stream containing aerosols and CO2. The aerosols have a size distribution with a peak diameter (δ) close to 0.3 µm and a horizontal initial particle velocity (vp,x ) of 2.4 m/s. The CO2 -concentration (c) emitted simultaneously is 7500 ppm. It is investigated, if the spatial dissipation of aerosols and CO2 can be correlated. This would allow the use of technically easier CO2 measurements to monitor compliance with aerosol concentration limits. Both aerosol and CO2 concentrations are mapped by different sensors placed around the mannequin. As a result, no significant enrichment of aerosols and CO2 was obtained outside a radius of 1.5 m when the fresh air ventilation in the concert hall has a steady vertical flow with a velocity of vg,z= 0.05 m/s and the installed ventilation system was operating at an air change rate per hour (ACH) of 3, corresponding to an air exchange rate of 51,000 m3/h. A Pearson correlation coefficient of 0.77 was obtained for CO2 and aerosol concentrations measured simultaneously at different positions within the concert hall.

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“…Several laboratory studies using mannikins have examined the potential effects of face shields but vary greatly in their design and their application to real-world settings. One study tested facing mannikins 25cm apart with the emitter sending an aerosol spray with particles with a range of size from less than 0.3µm to 10 µm; they found a reduction in particles received of 55% with face shields compared to 22% for a mask, and 97% for both 18 . A study with a mannikin 60cm from the spray found greater reductions and face shields providing greater protection than masks 19 .…”

Section: Discussionmentioning

confidence: 99%

The Effect of Eye Protection on SARS-CoV-2 Transmission: A Systematic Review

Byambasuren

Beller

Clark

et al. 2021

Preprint

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Background: The effect of eye protection to prevent SARS-CoV-2 infection in the real-world remains uncertain. We aimed to synthesize all available research on the potential impact of eye protection on transmission of SARS-CoV-2. Methods: We searched PROSPERO, PubMed, Embase, The Cochrane Library for clinical trials and comparative observational studies in CENTRAL, and Europe PMC for pre-prints. We included studies that reported sufficient data to estimate the effect of any form of eye protection including face shields and variants, goggles, and glasses, on subsequent confirmed infection with SARS-CoV-2.Results: We screened 898 articles and included 6 reports of 5 observational studies from 4 countries (USA, India, Columbia, and United Kingdom) that tested face shields, goggles, and wraparound eyewear on 7567 healthcare workers. The three before-and-after and one retrospective cohort studies showed statistically significant and substantial reductions in SARS-CoV-2 infections favouring eye protection with odds ratios ranging from 0.04 to 0.6, corresponding to relative risk reductions of 96% to 40%. These reductions were not explained by changes in the community rates. However, the one case-control study reported odds ratio favouring no eye protection (OR 1.7, 95% CI 0.99, 3.0). The high heterogeneity between studies precluded any meaningful meta-analysis. None of the studies adjusted for potential confounders such as other protective behaviours, thus increasing the risk of bias, and decreasing the certainty of evidence to very low.Conclusions: Current studies suggest that eye protection may play a role in prevention of SARS-CoV-2 infection in healthcare workers. However, robust comparative trials are needed to clearly determine effectiveness of eye protections and wearability issues in both healthcare and general populations.

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Experimental Efficacy of the Face Shield and the Mask against Emitted and Potentially Received Particles

Cited by 28 publications

References 52 publications

Evaluation of Face Shields, Goggles and Safety Glasses as a Virus Transmission Control Measure to Protect the Wearer Against Cough Droplets

Evaluation of Face Shields, Goggles and Safety Glasses as a Virus Transmission Control Measure to Protect the Wearer Against Cough Droplets

Experimental Investigation of Aerosol and CO2 Dispersion for Evaluation of COVID-19 Infection Risk in a Concert Hall

The Effect of Eye Protection on SARS-CoV-2 Transmission: A Systematic Review

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