Q&A: Which face masks offer best protection and what is Nphet advising?

Advisers say high-grade masks are better but people should only wear them if they want to

Nphet has advised that a medical mask rather than a cloth mask should be worn by anyone who is a confirmed Covid-19 case.
Nphet has advised that a medical mask rather than a cloth mask should be worn by anyone who is a confirmed Covid-19 case.

The State’s National Public Health Emergency Team has sent new advice to the Government on face masks and which varieties better protect people against Covid-19.

The recommendations have not gone as far as other countries where people are advised to wear high-grade respirator masks in public spaces.

What are the different type of masks that people are wearing?
Face masks are roughly divided into three groups: cloth face masks that most people wear in shops and on public transport; the slightly better medical grade masks that are mostly blue, and the even more protective high-grade respirator masks that can look like a duck's bill.

What are the best masks?
The FFP3 respirator face masks and slightly lower grade FFP2 (FFP stands for filtering face piece, by the way) offer the highest level of protection.

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They reduce exposure to airborne particles.

These masks must be worn tightly fitted to the face and reduce the wearer’s exposure to small particle aerosols, filtering out at least 95 per cent of these airborne particles. The US equivalents of the FF2 and the FFP3 masks are the N95 and the N99 respectively.

Why aren't medical grade masks as effective?
Medical masks do not protect against smaller airborne particles. They are often loose fitting, allowing leakage around the edges when the user inhales.

For this reason the US Centre for Disease Control and Prevention does not consider medical masks respiratory protection.

How effective are the basic cloth masks?
Fabric masks or face coverings such as homemade varieties do not protect you but may protect others if you are infected. They are not classed as official personal protective equipment.

What has Nphet told Government?
The advice is nuanced and discretionary for the most part. It says that all types of masks, including cloth masks, can reduce community transmission of Covid-19 if properly made, well-fitted and appropriately worn but that medical and respirator masks offer greater protection.

So is Nphet telling us we should be wearing higher quality masks?
Not really. It has stopped short of saying that people should wear them, leaving them up to the individual to decide.

It has advised that if people want to wear them, they should but only if the mask they choose fits well and is worn properly. For medically vulnerable and older people (aged 60 and over), Nphet has gone a little further.

These people are already advised to wear medical masks in crowded outdoor spaces or confined indoor spaces, but the public health team now says that these people may prefer to wear a respirator mask because they may offer a higher level of protection against inhaling particles of the virus that may help people who are at higher risk.

Are higher-grade masks suggested for other groups?
Yes. Nphet has advised that ideally a respirator or medical mask rather than a cloth mask should be worn by anyone who is a confirmed Covid-19 while infectious, who has symptoms, who is a household contact of a case or who is visiting a healthcare setting or a vulnerable person.

What else has Nphet advised?
It has said that the HSE should develop clear messaging on the different type of masks.

What has led to this new advice?
Minister for Health Stephen Donnelly asked the chief medical officer Dr Tony Holohan over Christmas to look again at the official advice on face masks and whether the public should be told to wear something more protective than a cloth mask in light of the spread of the Omicron variant.

What have other countries done?
In Germany, FFP2 respirators are mandatory on public transport and in shops, while they are mandatory in workplaces in Austria. In Italy, people were ordered just before Christmas to wear them on public transport and in public places such as theatres, cinemas and at sports events.

Why hasn't Nphet gone further?
This is not clear but the advice to the Minister emphasises that respirator and medical grade masks should be prioritised for healthcare workers and those in healthcare settings so guarantees around supply may be a factor in not recommending them for wider public use.

What do experts say?
Aoife McLysaght, a professor in genetics at Trinity College Dublin, said that clear messaging on the differences in the various types of face masks and their effectiveness is a good start.

“Even if people were given that information and if that information was made really clear, that would be a huge step forward, she said.

She believes FFP2 masks should be worn in confined indoor spaces such as on public transport.

“The quality of filtering in the FFP2 is much, much better and they tend to be a better shape and on average fit people better,” she said.

“On public transport, you are in an enclosed space and you have a bit less choice about who you are sharing the air with.

“If I was a bus driver, I would like all the passengers wearing that quality of mask. I would feel a lot more comfortable in my workplace.”

Simon Carswell

Simon Carswell

Simon Carswell is News Editor of The Irish Times