by Phillip C. Fincher, CIH, CSP
Senior Vice President, Health & Safety
EI continues to closely monitor the ongoing COVID-19 pandemic and provide our clients and the general public with current, relevant guidance based on our experience with Occupational Health, Industrial Hygiene, Safety Compliance and Engineering services performed during the pandemic. We have documented our progress, shared our learnings, and offered our insight for managing/minimizing exposures through our blog, which launched on January 27, 2020. An article, released on March 23, 2020, addressed engineering and administrative control options to minimize airborne exposure to COVID-19 in buildings and has received much interest following recent updates from the World Health Organization (WHO). This article was released prior to the WHO’s scientific briefing on July 9, 2020 to include the role of airborne droplets and aerosols to the recognized “Modes of Transmission.”
There have been numerous developments to the state of the science regarding modes of transmission with the CDC de-emphasizing the role of surface transmission on May 22, 2020. Although surface transmission is not currently thought to be the primary way the virus spreads, it remains a mode of transmission and does not negate the importance of frequent hand washing and disinfection of surfaces using EPA approved List N disinfectants as part of a comprehensive infection prevention strategy. The current position of the CDC and WHO indicates the virus appears to be mainly spread via droplets and close contact with infected symptomatic individuals. However, recent research suggest the potential for increased risk of airborne droplet and aerosol transmission in settings such as restaurants, nightclubs, places of worship or places of work where people may be shouting, talking, or singing. Airborne droplet and aerosol transmission is thought to have played an important role in the documented viral spread during choir practice in Washington State and for patrons in a restaurant in Guangzhou, China.
Aerosols generated by human breath are referred to as human generated aerosols (HGAs) or exhaled breath particles (EBPs). Research indicates that these particles range from less than 1 micrometer (um) to greater than 500 um; with most particles less than 1 micron during normal breathing. The volume or number of particles generated by individuals is highly variable and increases as speaking volume or forcefulness increases. Droplets are defined as particles (>5 um) and generally settle quickly to the ground and do not remain airborne for extended periods of time. However, smaller particles or aerosols (<5 um) are frequently less than 1 micron and may remain airborne for several hours. When coughing, sneezing, and speaking a broad range of particles and aerosols are generated that may travel well beyond 6 feet on indoor air currents. The evolving role of aerosols as a mode of transmission further complicates our ability to develop and implement control measures to break the chain of viral transmission.
With the increased use of cloth face coverings and surgical masks by the public, we can directly observe these droplets and aerosols as they form a fog on glasses or safety glasses. As many continue to resist the use of face coverings, it should be apparent from this fog that when used properly, they significantly reduce the spread of HGAs beyond the face covering and breathing zone. Numerous employers, commercial building owners, and retailers have mandated the use of face coverings, while the Commonwealth of Virginia has adopted an Emergency Temporary Standard for COVID-19 to require the use of face coverings and respiratory protection based on exposure risk.
On July 15, 2020, the Virginia Department of Labor and Industry adopted the nation’s first enforceable regulation regarding COVID-19 in the workplace. This standard is expected to be published before July 27,2020 and includes several requirements that exceed guidance from the CDC and WHO. Some of these include the requirement to perform and document a risk assessment to categorize employee tasks/exposures from “Very High” to “Low”. Employers with potential exposures in all risk categories except “Low” are also required to develop and implement an “Infectious Disease Preparedness and Response Plan.” There are also many tasks where cloth face coverings have been used that will now require the use of respiratory protection (e.g. N95-P100s) and other PPE. This requirement creates some unique challenges for many employers that do not currently have a Respiratory Protection Plan or on-site Occupational Health Resources for Respirator Medical Clearance and Fit Testing as required by the OSHA Respiratory Protection Standard. Guidance detailed in our blog released on February 13, 2020 provides an overview of the protection factors for different types of respiratory protection and additional requirements of the standard.
How Can We Help?
As our clients begin their efforts to address airborne transmission and comply with new requirements, EI’s team of Occupational Health Professionals, Industrial Hygienists, Safety Professionals and Engineers are here to support and guide your compliance initiatives. Our next series will provide an in-depth review of the Virginia COVID-19 Standard and practical solutions for compliance with the standard and other best practices for infection prevention and control.
If you have any questions regarding workplace ventilation and indoor quality or other COVID-19 pandemic concerns, please contact Phil Fincher, CIH, CSP, Senior Vice President of Health and Safety, at 919-657-7500 or email@example.com.