Explainer: answers to all your questions about wearing a mask
Masks have almost become synonymous with the Covid-19 pandemic.
Many people in New Zealand choose to wear the generic black cotton mask, but others like to get creative by choosing masks with a bold print, glittery material or clear window.
Some choose to use disposable or surgical masks. There are masks with exhalation valves, masks with wool filter inserts and even masks that claim to be self-sterilizing.
But how well can a mask really protect you against a highly transmissible virus, and does your choice of mask have a significant impact on your chances of staying Covid-free?
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Yes, your choice of mask matters – but how much depends on a number of factors.
There is no doubt that masks are an effective way to minimize the transmission of Covid-19, even with the more transmissible Omicron variant, says Dr Joel Rindelaub, aerosol chemist at the University of Auckland.
“Omicron is so new that we haven’t been able to publish much peer-reviewed literature on this specific variant, but we do know that masks work. But there is a wide range of different types [of masks] and how well they work.
Rindelaub says that because cloth masks have the most variability, they are more likely to fail to provide sufficient protection against a highly transmissible aerosol virus like Covid-19.
A disposable medical mask is a better choice because it is specifically designed for source protection and control – using masks to protect others by reducing the spread of respiratory droplets to others when a person talks, sneezes or coughs – and there is consistency in how they are made.
But don’t think that a mask labeled as “surgical” is necessarily better than the others.
Tests carried out by the Environmental Protection Agency in the United States showed that a surgical mask only filtered 38.5% of particles, while N95 respirator masks blocked up to 95% of harmful particles and P2 masks have a filtration level of 94.5%.
A P2, FFP2, N95, KF94 are the safest options, especially for those who work in roles where they have a lot of contact with others such as teachers or supermarket workers, Rindelaub says.
He suggests avoiding KN95 masks, a mask designed to meet Chinese standards and which also blocks 95% of harmful particles, simply because of a large amount of fake KN95 masks on the market.
“The Centers for Disease Control and Prevention said more than half of those on the market are counterfeits.”
Rindelaub suggests buying masks at your local hardware store or pharmacy. Masks can also be purchased online, but users should be careful to avoid retailers who cannot guarantee the authenticity of their products.
Northland physician Dr Nitasha Rimar recommends avoiding masks with exhalation valves, gaiters or bandanas, and unfitted transparent masks or face shields that offer little or no protection.
“The best mask is the one that provides the snuggest fit and highest filtration, while maintaining breathability and comfort to ensure compliance.”
You can find more information about the different types of masks here.
Get the most out of your mask
According to the Centers for Disease Control and Prevention, a properly fitting mask will have no gaps and will prevent air from leaking from the area near your eyes or the sides of the mask.
“If the mask fits snugly, you will feel warm air coming through the front of the mask and you may be able to see the material of the mask moving in and out with each breath.”
People with beards can use a mask adjuster or splint to help the mask fit snugly on their face.
When you wear a disposable mask, the colored side – usually blue – goes on the outside, and the edge with a piece of yarn, or something similar, goes over your nose. The colored side is water resistant, while the white side is more absorbent and will suck up droplets and aerosols produced by the wearer.
While experts agree that double masking is not necessary when wearing a properly fitted mask, a disposable mask can be worn over a cloth mask.
This is preferable to the cloth mask rather than the disposable mask, says Dr Arindam Basu, associate professor of epidemiology and environmental health at the University of Canterbury.
“Only because it keeps the cloth mask slightly cleaner than if worn the other way around, and the disposable mask can be thrown away and changed.”
Basu says that ideally a cloth mask should be washed every time the wearer takes it off, but acknowledges that this could be inconvenient for many people. Cloth masks should be washed at least once a day.
“Keep in mind that pathogens can last for eight hours on cloth masks, so washing your mask frequently is recommended.”
Rindelaub recommends keeping a number of clean face masks on hand to rotate throughout the day.
A research project conducted last year by Dr Richard Everts, an infectious disease specialist and microbiologist for Nelson Bays Primary Health and Nelson Marlborough Health, found that disposable medical masks can be washed up to 10 times and still provide a better protection than homemade cloth masks.
While useful in case of pinching, it’s best to throw away disposable masks after wearing them once, Rindelaub says, because effectiveness is reduced with each wash.
According to Centers for Disease Control and Prevention guidelines, you should always wash or sanitize your hands before putting on a mask, avoid touching your mask while wearing it, use the ear loops to remove the mask and wash yourself hands immediately after removing it.
Store clean masks in a dry, breathable bag (like a paper or mesh bag) for later use, and reusable masks that have been used in a sealed plastic bag to wash later.
And don’t slack off on wearing the mask when you’re outside.
“Particularly with a strain like Omicron, the risk of transmission to others is much higher. Therefore, if someone is going outside and is likely to be in a crowded outdoor situation, a mask should be worn. says Basu.