Risk of Contracting SARS-CoV-2 from Surfaces is Less Than 1 in 10,000

April 9, 2021

The CDC has updated their SARS-CoV-2 and Surface Transmission guidelines, stating that the chance of contracting the coronavirus from surfaces is less than 1 in 10,000.

This comes after mounting evidence that the virus primarily spreads through airborne droplets, which can remain in the air for minutes to hours. “The length of time [the] virus remains suspended and is infectious depends on numerous factors, including viral load in respiratory droplets or in small particles, disturbance of air and surfaces, ventilation, temperature, and humidity.”

The infection rate within the community, the amount of viral shedding by those who are infected, and the interaction between virus particles and the environment, are some factors that can increase the risk of viral transmission. This reinforces the necessity of wearing masks, especially in closed spaces, to reduce the spread of the virus both in the air and on surfaces.

The CDC also states that “in most situations, cleaning surfaces using soap or detergent, and not disinfecting, is enough to reduce risk.” The envelope (the outer layer of proteins and lipids) housing the genetic material of the SARS-CoV-2 virus is easily altered and can “degrade quickly upon contact with surfactants contained in cleaning agents and under environmental conditions.” Cleaning agents alone can remove the virus from surfaces. However, to “substantially inactivate” the virus on surfaces, it must be treated with a disinfectant product. Increasing ventilation is one way of reducing the risk of airborne transmission.