Reprinted with permission, Cleveland Clinic Foundation ©2022. All Rights Reserved Background: Barriers are commonly installed in workplace situations where physical distancing cannot be maintained to reduce the risk for transmission of respiratory viruses. Although some types of barriers have been shown to reduce exposure to aerosols in laboratory-based testing, limited information is available on the efficacy of barriers in real-world settings.  Methods: In an acute care hospital, we tested the effectiveness of in-use plexiglass barriers in reducing exposure of staff to aerosolized particles. A nebulizer was used to release 5% NaCl aerosol 1 meter from staff members with and without the barrier positioned between the point of aerosol release and the hospital staff. Particle counts on the staff side of the barrier were measured using a 6-channel particle counter. A condensed moisture (fog) generating device was used to visualize the airflow patterns.  Results: Of 13 in-use barriers tested, 6 (46%) significantly reduced aerosol particle counts detected behind the barrier, 6 (46%) reduced particle counts to a modest, non-significant degree, and 1 (8%) significantly increased particle counts behind the barrier. Condensed moisture fog accumulated in the area where staff were seated behind the barrier that increased particle exposure, but not behind the other barriers. After repositioning the ineffective barrier, the condensed moisture fog no longer accumulated behind the barrier and aerosol exposure was reduced.  Conclusion: In real-world settings, plexiglass barriers vary widely in effectiveness in reducing staff exposure to aerosols, and some barriers may increase risk for exposure if not positioned correctly. Devices that visualize airflow patterns may be useful as simple tools to assess barriers.

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Background Barriers are commonly installed in workplace situations where physical distancing cannot be maintained to reduce the risk for transmission of respiratory viruses. Although some types of barriers have been shown to reduce exposure to aerosols in laboratory-based testing, limited information is available on the efficacy of barriers in real-world settings. Methods In an acute care hospital, we tested the effectiveness of in-use plexiglass dividers in reducing exposure of staff to aerosolized particles. An aerosol sprayer was used to release 5% NaCl aerosol at 1 or 2 meters from staff members with and without the barrier positioned between the point of aerosol release and the hospital staff. Particle counts on the staff side of the barrier were measured using a 6-channel particle counter. A condensed moisture (fog) generating device was used to visualize the airflow patterns. Results Of 13 dividers tested, 6 (46%) significantly reduced peak aerosol particle counts detected behind the divider, 6 (46%) reduced peak particle counts only to modest non-significant degree, and 1 (8%) significantly increased particle counts behind the divider; the figure shows data for 3 dividers that illustrate the 3 types of results. For effective dividers, condensed moisture fog flowed around the divider toward outlet air vents positioned in the ceiling, whereas fog pooled immediately behind the divider that increased staff exposure before exiting in an outlet air vent positioned on the side wall. Effective divider reducing staff aerosol exposure Ineffective divider increasing staff aerosol exposure Minimally effective divider Conclusion In real-world settings, plexiglass barriers vary widely in effectiveness in reducing staff exposure to aerosols, and some barriers may increase risk for exposure. Devices that visualize airflow patterns may be useful as simple tools to assess barriers. Disclosures All Authors: No reported disclosures.