askST: Clearing the fog of uncertainty on mask protection
Can a surgical mask be worn two ways, and does it protect against the haze? With air pollution hitting unhealthy levels here, and misinformation rife on how and when to wear various masks, The Straits Times shows you the correct mask to wear for different scenarios, and how to wear it.
Sign up now: Get ST's newsletters delivered to your inbox
There is only one way to wear the good quality surgical masks that most people are familiar with - with the coloured side facing outwards.
ST PHOTO: LIM YAOHUI
Jacklin Kwan
One reader asked The Straits Times whether it is true that the white side of the surgical mask is the filter, citing information online which said that when people are sick, they should be wearing the mask with the white side facing towards them to prevent their germs from escaping. It added that people should wear the mask with the white side facing outwards if they want to protect themselves from pollution and illness.
This is false.
Good-quality surgical masks that most people are familiar with have three layers: Two outer layers (one white and one coloured), and a middle layer that acts as a filter. There is only one way to wear them: With the coloured side facing outwards.
The white side is actually an absorbent material, according to the Health Sciences Authority (HSA). Breathing with a mask on can often feel humid and uncomfortable, and this absorbent white layer is meant to help with that.
Both the middle and coloured outer layers are water-repellent to prevent any bodily fluids (for example, sweat, blood or mucus) from being absorbed into the mask. Wearing the mask the wrong way round can reduce its effectiveness and increase discomfort.
Surgical masks also do not provide adequate protection from environmental pollutants. They are typically worn to prevent splashes of bodily fluids (for example, from sneezes and runny noses) from being exchanged between the wearer and anyone else.
As they do not fit tightly around a wearer's mouth and nose, pollutants can be breathed in from the sides of the mask. Surgical masks are also not designed to filter small dust particles but are, instead, designed to catch aerosols or liquid droplets.
To protect themselves from the haze, people should use an N95 respirator. These masks are designed for a better fit than conventional surgical masks.
Users should look for masks that fit over the mouth and nose snugly and that have at least a 95 per cent filtration efficiency. They should also carefully follow the instructions on how to wear the mask.
HSA advises people not to wear the same surgical or N95 mask for an entire day, and to change masks regularly. The make of different respirators varies slightly, so wearers should read the specific instructions for their mask to find out how long they should be wearing it.
Users should also minimise the amount of talking they do behind a mask to reduce condensation, which may reduce the mask's effective lifespan.
•Not sure if something is fake news? Readers can send an e-mail with their questions and a link to the suspect article to askst@sph.com.sg
•Reports published can be found on the ST website under a special "fake news debunked" section at http://str.sg/fake-news
