By now, many of us have built up a small collection of reusable face masks that we have on rotation. But with the new variant spreading quickly and reports from overseas about higher-grade medical masks being required in some public places, it's time to take stock of what you're using to cover your face.
Growing concerns about the faster-spreading COVID-19 variants have prompted France to ban certain homemade masks from being worn in public in favour of higher-grade ones, while Germany and Austria now require 'filtering face piece' (FFP) masks to be worn on public transport and in shops.
There's no such change here yet, though a BSI Flex Standard is in development which would set a minimum limit on filtration efficiency (how well the mask blocks particles from escaping).
The advice until now has largely been that for the public, reusable face coverings are a more practical, economical and environmental option than higher-grade medical masks, which are needed by healthcare professionals and are often single-use, and require specialist fitting to be effective.
For now, this advice still stands, though the World Health Organisation (WHO) does advise if you are older or vulnerable to consider wearing a disposable surgical mask in some circumstances.
But if your reusable masks are looking a bit tired and worn, don't fit well, or only have one or two layers, it's time to upgrade your personal protective arsenal.
FFP masks are designed to protect the wearer from breathing particles in, as well as filtering exhalations. These masks must comply with British Standard EN149:2001 and be CE marked.
FFP masks should be moulded to the face, to create a seal where no air can slip out. They are labelled one, two or three, according to filtration efficiency.
FFP2 and FFP3 masks filter above 94% and 99% of bacteria respectively, so these are the ones being referred to. FFP2 respirators are roughly the equivalent of N95 masks in the US or KN95 respirators in China.
However, they aren't very practical for everyday use by the public on a global scale, for cost, environment and supply reasons.
They're mostly single use, so the impact on the environment is significant, and keeping up a regular supply of these will take a toll on your finances too. If there's a sudden rush to buy these masks, we could be facing similar concerns about lack of PPE for frontline staff as we did last spring.
The other caution is that these masks really need to be fitted properly to do the job - otherwise air will just escape around the edges (particularly if you have any facial hair).
The French ban on homemade face coverings applies to 'fabric masks with lesser filtering qualities' of around 70%. But many of the face coverings we tested comfortably exceeded this cut-off.
Face coverings that had a bacterial filtration efficiency (BFE) of below 70% in our tests were judged to have failed, and we named them Don't Buys.
The worst offenders were all single-layer stretchy masks. We'd like to see these removed from the market as we don't think they are up to scratch.
The face coverings that were rated highest for filtration in our tests were able to block more than 99% of bacterial particles penetrating the mask material. They were slightly less breathable than our overall Best Buy options, but you may be happy to make that trade-off.
It should be noted that coronavirus particles can be much smaller (as little as 0.1 micrometre in diameter), but measuring bacterial filtration efficiency is the standard test for products of this type and allows us to get an idea of how well face coverings provide a barrier for particles generally, using bacteria as a proxy.
There are several options for improving how effective your face covering is:
The face coverings that did best in our filtration tests used disposable filters that you insert into the mask and change frequently.
Similarly, there are some 'semi-disposable' masks now on the market. These claim to have higher filtration specs but also allow you to wear and wash them a set number of times before they have to be thrown away.
For example, the mask above from AirPop says it can be worn for up to 40 hours before disposal (though there are caveats around this and it says washing the mask will reduce filtration efficiency).
Boots is selling an Alvita Reusable barrier mask that can be washed and reused up to 30 times, and fashion brand Edeline Lee is selling masks made of spunbond polypropylene (the filtering material used in disposable masks) which it says can be handwashed ten times before discarding.
We haven't tested these masks yet, but will be including some in our next lab tests.
One idea gaining traction is the idea of double-masking. If you watched the US presidential inauguration ceremony you might have spotted a few double-maskers in the audience, and US Chief Medical Adviser Dr Anthony Fauci is apparently a fan.
The idea is that wearing two masks - a disposable surgical mask as the inner and a reusable face covering as the outer - is better than one. Essentially, the disposable mask acts like a filter layer, and the outer covering helps to encourage a snug fit.
A new study form the Centre for Disease Control (CDC) in the US has found that 'double-masking' can reduce the risk of infection.
If you are feeling particularly anxious about busier, enclosed environments, this could be an option. The principle behind it is ultimately still that more layers = better filtration. And you still need to ensure you can breathe freely and there aren't big gaps round the edges.
With all these options, it's worth bearing in mind that disposable masks and filters are an ongoing cost, and do create waste compared to a fully reusable covering.
Arming yourself with the best reusable covering option, remembering to still keep your distance even when wearing a mask, practicing good hygiene and washing your mask properly are all still key to protecting yourself and others.
It may be that for higher-risk encounters, where you are more enclosed for a sustained period with other people, you might want to swap in a disposable mask, or double up.
It's also worth trying to avoid 'rush hour' at the shops if you are able to shop at other times.
It's definitely a good time to do a stock take of the face coverings you have, and see if any are a little past their best.
If your face covering is becoming loose, misshapen, or the elastic is wearing thin - it's time to get a new one. Same goes for if the nose bridge no longer fits very well or if the material is visibly worn.
Also think about how long you've had the face covering and how many washes it's been through. There's no hard and fast rule here, but if you've been heavily washing and wearing the first fabric face covering you bought back in June, it's likely to be past its best.