It might be time for a rethink if you’re using a face mask with an air vent or valve in the front.
An update from US-based Centers for Disease Control and Prevention (CDC) now advises against masks with exhalation valves or vents.
They had originally been hailed as coverings that made breathing easier for the wearer, but the public health institute has questioned their effectiveness against the spread of Covid-19.
“The purpose of masks is to keep respiratory droplets from reaching others,” CDC says. “Masks with one-way valves or vents allow exhaled air to be expelled out through holes in the material. This can allow exhaled respiratory droplets to reach others and potentially spread the Covid-19 virus.”
It’s not the first time these masks have been called into question. Back in May, the San Francisco Department of Public Health took to its Twitter account to advise people against the use of N95 masks with valve openings in the front.
“Still seeing a lot of these masks out there, it's confusing, because they are called N95, but the ones with the **valves** or openings on the front are NOT safe, and may actually propel your germs further!!,” read the tweet.
Still seeing a lot of these masks out there, it's confusing, because they are called N95- but the ones with the **valves** or openings on the front are NOT safe, and may actually propel your germs further!! @SFFDPIO @SFPD @sfgov @LondonBreed @MyrPressOffice https://t.co/xHxNy28EUz— SFDPH (@SF_DPH) May 4, 2020
Bearing in mind the purpose of a mask is less about protecting the wearer and more about preventing the wearer from spreading the virus to others, this makes sense.
“Although any type of mask is better than nothing, using masks that are ineffective does not help in the fight against the virus,” chief medical officer of the healthcare website WebMD, Dr John Whyte told Fox News.
“I know everyone wants comfort when wearing a mask, but the key for protection is a good seal – thereby keeping as many infectious particles that we can from affecting other people.
“The problem with the valves is that although they prevent particles from coming in, they allow particles to come out — defeating the purpose of infection control.”