As states relax their restrictions in the coming weeks and months, non-essential businesses may be permitted to reopen conditionally. Concerns about the transmission of COVID-19 remain amongst the workforce. Undoubtedly once shelter-in-place orders have been lifted and employers are permitted to reopen their workspaces, they will need to do so with caution.
Protective measures have been published by the CDC, and include:
- Regular cleaning and sterilizing of surfaces.
- Providing adequate personal protective equipment for employees.
- Installing barriers such as sneeze guards and social distance markers at customer interaction points
- Implementing, promoting and enforcing social distancing guidelines and employee training to prevent transmission
Additional strategies for safeguarding the workplace are presented. I discuss common-sense measures to ensure safety. Some of these might present logistical challenges, but these can be overcome. There is no one-size-fits-all strategy, but instead are conceptual measures that can be adapted to fit specific workspaces.
Negatively pressurize the workspace.
Within a closed environment, air will remain stagnant. Potential pathogens will also remain stagnant. It makes sense to remove stagnant air and replace it with fresh air. Conceptually, this can be accomplished by placing a fan (oriented backward) in an open window. Ideally the fan should be placed at a distance from and out the pathway of people. Next, where possible, open a window (if only a few inches) across from the backward-faced fan. This has the effect of displacing stagnant air (and associated viral particles) and replacing it with fresh air. Overall you may need to carry out adaptations to the layout of the workplace to accomplish this. Common-sense should rule. Do not place a person in the pathway of the fan and an open window. Keep people away from the flow of air.
Portable HEPA-filtration systems
HEPA is an acronym that stands for High-Efficiency Particulate Air (HEPA). These systems can remove small particles, including viruses. HEPA filters, as defined by the United States Department of Energy (DOE) standard adopted by most American industries, remove at least 99.97% of airborne particles 0.3 micrometers (μm) in diameter. Coronavirus particles range from 0.06 to 0.125. Particles as small as the coronavirus, and other nano-particles get captured using a scientific phenomenon called diffusion. Diffusion is surprisingly effective at capturing tiny virus-sized particles. According to NASA, HEPA filters capture “virtually 100% of particulates.”
It makes sense to utilize portable HEPA filtration systems. This in conjunction with other measures can contribute to a safe workspace. These systems are readily available and are affordable.
Ultraviolet (UV) light is a form of light that is invisible to the human eye. It occupies the portion of the electromagnetic spectrum between X-rays and visible light.
UV provides rapid, effective inactivation of microorganisms through a physical process. When bacteria, viruses and protozoa are exposed to the germicidal wavelengths of UV light, they are rendered incapable of reproducing and infecting. UV light has demonstrated efficacy against pathogenic organisms, including viruses.
Units are commercially available and relatively inexpensive. They can be used in conjunction with HEPA filtration.
N95 respirators reduce the wearer’s exposure to airborne particles, from small particle aerosols to large droplets. N95 respirators are tight-fitting respirators that filter out at least 95% of particles in the air, including large and small particles.
Not everyone is able to wear a respirator due to medical conditions that may be made worse when breathing through a respirator. When properly fitted and worn, minimal leakage occurs around edges of the respirator when the user inhales. This means almost all of the air is directed through the filter media.
N95 respirators are designed to block at least 95% of airborne particles, but many HCWs find them uncomfortable. It can be challenging to put on these masks and wear them for prolonged periods of time.
The Centers for Disease Control and Prevention (CDC) does not recommend that the general public wear N95 respirators to protect themselves from respiratory diseases, including coronavirus (COVID-19). The rationale is that they are critical supplies that must continue to be reserved for health care workers. On the other hand, businesses are not precluded from using N95 masks.
 Barnette, Sonya. “Specification for HEPA Filters Used by DOE Contractors — DOE Technical Standards Program”. http://www.standards.doe.gov. Retrieved 2019-06-05.
 Na Zhu, Ph.D., Dingyu Zhang, M.D. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med 2020; 382:727-733, DOI: 10.1056/NEJMoa2001017
 J.L. Perry Marshall, R. Vijayakumar Submicron and Nanoparticulate Matter Removal by HEPA-Rated Media Filters and Packed Beds of Granular Materials NASA/TM—2016–218224https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170005166.pdf
 Infographic: Understanding the difference between surgical masks and N95 respirators. https://www.cdc.gov/niosh/npptl/pdfs/UnderstandDifferenceInfographic-508.pdf