Last updated April 22, 2020

The CDC now recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain–like at grocery stores and pharmacies.

At UCSF Health we support the use of face masks or face coverings. Please note that physical distancing (maintaining at least 6-feet away from others) is still required, even when wearing a mask.

Reasons we support the use of face masks:

  • The highly contagious nature of the virus
  • The potential for asymptomatic and pre-symptomatic transmission
  • Empiric evidence from Asia, where masks are routinely used

Supplies of hospital-grade masks for health care workers must continue to be a priority, but extra surgical masks or homemade masks of multilayered cotton will likely provide more protection compared to wearing nothing during this epidemic. It is important to avoid wearing a mask that contains a valve (typically a raised plastic cylinder about the size of a quarter on the front or side of the mask) that is designed to facilitate easy exhaling. The latest Order of the Public Health Officer in San Francisco (C19-12 "Requiring Face Covering") specifically prohibits masks of this type. Valves permit droplet release from the mask, putting others nearby at risk.

An increasing number of cities in the U.S. are embracing this recommendation: "Stay in place, keep your space, and cover your face."