-
Photo: Images by Tang Ming Tung / Getty Images
Photo: Images by Tang Ming Tung / Getty Images
Wearing a mask every time you leave your home to prevent the spread of COVID-19 has become for most of us routine. But if burns are raging across Northern California, it’s easy to ask if that cloth mask you normally reach for is the best kind to wear now.
The problem with dust masks, according to UCSF professor of medicine John Balmes, is that they are variable. Some masks are homemade, some have only two layers of fabric as opposed to the three layers recommended by the CDC and these dust masks can be made from a wide variety of materials. Overall, Balmes said that cloth masks do not do much to filter out the fine particles that can produce fire smoke. ‘We do not know how well [cloth masks] filter, ”he said. “While they are good at preventing the transmission of the virus, they do very little in terms of filtering fire smoke.”
Surgical masks, which are designed to protect against large respiratory drops, are standardized by the FDA. Balmes said they are about a third as effective at filtering the particles as N95 masks, the best masks for filtering fire smoke. This makes them a slightly better alternative to dust masks. “A surgical mask can be a big compromise if you can get that,” said Jahan Fahimi, UCSF associate professor of emergency medicine and medical director of the UCSF Emergency Department.
While N95 masks are best protected against smoke from burns due to their tight fit and protection against small particle aerosols, N95 masks are a short supply and should be reserved for healthcare professionals. Alternatives have emerged that avoid the N95 mask, said Balmes, best known as KN95 masks. He said they are actually nice at filtering these small particles, and if you can get one it is a great, close alternative to an N95.
If you have N95 masks, it is still important to remember that they lose their effectiveness after about five to six times that they have been taken on and off, Fahimi said. You still need to change it frequently to ensure the best protection.
It is also important to remember that N95 masks with a valve are not good to protect against COVID-19, so you will need to place a piece of tape over the valve or wear a mask over the N95.
“I do not think people need to go and get N95 masks if they can stay indoors,” said Fahimi. “Occupational workers who for any reason need to be in the outlying areas probably need to have an N95 if they are anywhere near the fire pit.”
Finally, Fahimi said that even an old N95 is better than a canvas mask for fire smoke.
But the most important thing to remember is that any mask is better than no mask at all. Protecting against COVID-19 is especially important at this time because the health care system could see increased pressure on the system, as they care for those with adverse effects of smoke from burning.
Influenza season is also approaching, and although medical professionals hope that widespread mask use will reduce the severity of flu season, this could put extra stress on the healthcare system.
“We still want people to wear any kind of mask right now,” said Stephanie Christenson, UCSF assistant professor of medicine. “This is just another reason to have shelter.”
Tessa McLean is a digital editor with SFGATE. Email her at [email protected] or follow her on Twitter @mcleantessa.
