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8 October 2021

Wash your disposable masks, experts say

Group of Kiwi researchers say you can wash a disposable mask 10 times and they still filter better than cloth ones.  

Disposable masks, which we’ve been advised to throw out after each wear, can actually be washed and reworn, a group of New Zealand researchers has found.  

In good news for both the environment and our wallets, a study by the researchers, which includes infectious disease experts, found disposable masks washed 10 times did a better job at filtering than cloth masks.

The masks were washed in one of eight different ways, with washing in warm water the method that had the least effect on filtration rate.

Dr Richard Everts washes his disposable mask under warm water, the best method according to the paper he was the lead author of.

Nelson-based infectious disease specialist physician and microbiologist Richard Everts pulled the group together more than a year ago to carry out the study. He’s excited to finally be able to tell people it was OK to not throw out their disposable masks after one use.

“I was working in Vanuatu when I first heard about Covid-19 spreading through China and I was thinking ‘this is not going to be good here’,” Dr Everts said.

“They had very few masks at that time for a population of over 300,000 and then when new supplies did arrive, I knew they weren’t going to be able to use them once and throw them out. So that got me started with the whole idea of how long masks can be used for.”

Dr Everts said he wasn’t surprised that disposable masks held up well.

“They’re an extremely refined product. They’re strong, they’ve got three layers and I suspected they would withstand some washing.”

In the study, three disposable mask brands that complied with the European standard, were washed eight ways.

After they had been washed 10 times, these standard-compliant disposable masks had better filtration efficiency than new non-compliant masks and fabric samples, even when the fabric was triple-stacked.

After warm water, the least damaging methods were soaking in hot water and boiling water. Filtration efficiency was affected more when they were washed with dishwashing liquid, hand soap, bleach and in a washing machine.

“People in developing countries and people using masks in the community in New Zealand are already doing this and so we want to get the message to those people that it’s OK and they are best to avoid soap or detergent,” Dr Everts said.

He said massaging the mask in warm water would remove biological material, such as mucus and saliva, and hanging it up to dry overnight was what disinfected it. If you were planning to share the mask with someone else, you should submerge it in boiling water for a few minutes before hanging it to dry.

He said using soap, dishwashing liquid or bleach affected the electrostatic charge on a mask’s middle layer, making it less effective but still better than cloth masks.

Dr Everts said from an infection point of view he’d rather see people wearing disposable masks than cloth.

“Some cloth masks are sewn by well-meaning people and they’re better than no mask, but there’s a lot of published research that shows most cloth masks are very poor at stopping viruses. Based on our research and others from overseas, a good quality commercial medical mask washed in warm or hot water 10 times will still be better than 90 percent of the cloth masks out there.”

Co-author Lucy Telfar Barnard, an epidemiologist at Otago University in Wellington, also said she’d prefer people wore a disposable mask than a cloth mask, but only if it fits well.

“I don’t want to say people are wrong to be wearing reusable, because if you’ve got one that’s three layers and it fits you well it will be better than one that doesn’t fit. But if you don’t have one that fits well and you’re looking at what to buy in the future, if you can get a good fit with a surgical mask, I’d prefer people to do that,” Dr Telfar Barnard said.

She encouraged people to fiddle around with a disposable mask to get a good seal around the face. “The problem with disposable masks is it can be hard to get a good fit because they’re one size fits all, but you can get tricky with the elastics and tucking bits in.”

Dr Everts said healthcare workers or people in high-risk situations should always wear a new face mask. He said employers of people in essential services should be supplying their staff with new, high-quality disposable masks. The Ministry of Health recommends disposable masks be discarded after one use.

Dr Telfar Barnard said most masks sold in New Zealand were compliant with the European standard or another standard from around the world, which showed they had been tested and were good quality.

See our mask buying guide for more information on choosing a mask.

Member comments

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Shona M.
05 Feb 2022
are 'resting periods' OK for re-using disposable masks?

I've read elsewhere (articles by The Smithsonian magazine and Siouxsie Wiles) that the higher grade KN95, P2, N95 etc masks, can be re-used several times simply by 'resting' them for several days by hanging and/or storing in paper bags, although those ones should not be washed. Apparently the resting period gives enough time for the virus to die. I wonder if the same principle can be applied to the disposable masks?

Robin B.
10 Nov 2021
Visor/plastic shields instead of masks

A few of the big store chain shops have security people at their store entrances to ensure that customers sign in and wear masks. But a few of them have these security people wearing visors and not masks. I feel this is a dangerous situation, with these security people not wearing masks, especially in our very low vaccination area. I have phoned one store and they have acted, but the other has not replied to my emails requesting their policy regarding their staffs mask wearing. I feel this is a breech of our NZ Govt rules, and is very disappointing. These staff members certainly should not be at the front of store manning the mask security or at the tills where customers pay for the goods purchased. If they have a legal mask exemption because of their lungs condition, they simply should not be working in a high exposure situation. This attitude from this big company in my view is very disappointing, and is not playing their part in the
5 million fight against Covid 19.

Natasha S.
16 Oct 2021
Washing Disposable Masks

The article mentioned the best method to wash a disposable mask was by using warm water. However I was wondering if this needs to be done by hand like the picture in your article, or if masks could be put in a lingerie bag and popped in the warm cycle of a washing machine?

Kate H.
18 Oct 2021
Re: washing disposable masks

Hi Natasha, that would work as the washing part is really about removing biological material, like Dr Everts says in the article. But you'd be using a lot more water than necessary.

Linda M.
10 Oct 2021
Cutting/breaking cords when disposing of all masks

As well it would be great if the value of cutting or breaking the loops of the cords of this new environmental hazard before disposal could be publicised - they're a huge strangulation hazard for fauna. A request on packaging from companies manufacturing and selling them would help also.

J W.
10 Oct 2021
Disposing of masks near fauna?

This reasoning is broken! In a country with waste disposal infrastructure, why would you dispose of face masks where "fauna" could access them? Someone who is going to just biff their mask on the ground isn't about to cut its loops. How about the packaging requests "dispose in a refuse facility"?

Jack N.
09 Oct 2021

Good news,

Colleen M.
09 Oct 2021
In response to Paul

Hi, Paul,

Yes, the masks I use are exactly the same as the ones pictured in the article. Flat, pleated, blue on one side and white on the other. Maybe you were looking at the higher grade medical ones on the website?

Liz B.
09 Oct 2021
More specifics please

Please can you list the name of the 3 maaks

Kate H.
13 Oct 2021
Re: More specifics please

Hi Liz, the brands of the standard-compliant masks were Primagard (Canada), Ecoma (China) and another one from China that didn't have a brand name.

Colleen M.
09 Oct 2021
Disposable medical masks

I have been ordering Bactive medical masks online. Zuru, who manufacture the masks as part of their extensive PPE range, state on their website that they supply the Ministry of Health and the product conforms to standard EN 14683. This seems to be the standard that medical face masks in Europe are required to comply with. They are the best fitting disposable medical masks I have worn and currently retail for $20 for a box of 50.

Paul W.
09 Oct 2021
Thanks Colleen

That’s very helpful. I’ll give them a try. But they’re not the blue sort shown and quoted in the article. So maybe not washable.

Paul W.
09 Oct 2021
Confusion over masks meeting European standard

The article states "In the study, three disposable mask brands that complied with the European standard, were washed eight ways." But when I searched online for 'face mask complying with European standard' I discovered no actually blue face masks that stated they were compliant.

Some blue face masks state they are compliant to GB/t32610 standard. Don't be fooled. GB does not refer to a UK standard. It's a Chinese standard "English of Chinese Standard (GBT 32610-2016, GB/T32610-2016, GBT32610-2016): Technical specification of daily protective mask".

So please can you urgently provide more specific information as to which blue face masks are available in NZ that are safe to wash up to 10 times?

Kate H.
13 Oct 2021
Re: Confusion

Hi Paul, we'll add some info to the article about this. Dr Telfar Barnard told us when choosing a disposable mask to check that it meets at least one of the different standards from around the world, such as the EN 14683 European standard, because it shows it’s been tested. She said most disposable masks we can buy in New Zealand would meet a standard and be high quality, and therefore able to be washed.

Gena M.
09 Oct 2021
Research paper

Please provide a link to the research paper

Lyndon F.
10 Oct 2021
This is not helpful to thos who work in NZ healthcare

I work in infection prevention in aged care and just reviewing the comments already written, one can see the gaps in the study and report. These don't appear to be masks that we have access to here in NZ, thus the headline is very misleading. I would have thought we could have done much better at the delivery of such research and the use of such a headline.

Kate H.
13 Oct 2021
Re: Research paper

Hi Gena, here is the paper on the study https://pubmed.ncbi.nlm.nih.gov/34564717/

Kate H.
13 Oct 2021
Re: This is not helpful to thos who work in NZ healthcare

Hi Lyndon, the study was carried out in New Zealand using masks available here too.

Stewart C.
09 Oct 2021
Dangerous phrasing

Reading this article, the key thing about the disposable masks being discussed here is that it applies to masks with an electrostaticly charged middle layer. Unless I’m very much mistaken, this does NOT apply to most disposable masks. Please check this, and if it does in fact only apply to very specific types of disposable masks, please make that very clear throughout the article. Otherwise this is potentially very harmful.

Alistair C.
09 Oct 2021
Info in article

I think the important sentence in the report is regarding the European standard. If your masks don't meet this stnadard then the information would not apply.

"In the study, three disposable mask brands that complied with the European standard, were washed eight ways."

Kate H.
13 Oct 2021
Dangerous phrasing

Hi Stewart and Alistair, most disposable masks available in New Zealand will meet the European standard or another from around the world and be high quality according to co-author Lucy Telfar Barnard.

Jean M.
09 Oct 2021
Cloth masks with washable filter inserts

It would be helpful to know the effectiveness of cloth masks with washable inserts. I have several three layer cloth masks with pockets for the inserts, which are claimed to be “high quality” . They are constructed to fit the shape of the mask. I like this arrangement because the masks are very comfortable and fit well, and it’s fun to have colour choices.
Also, masks with ear loops are no good at all when you have glasses plus hearing aids, so mine must have head straps.

Could Consumer carry out follow up research to explore the cloth mask plus filter?

Jana F.
09 Oct 2021
Glasses and hearing aids

I have the same problem. Are there masks with head straps available or are they only DIY?

Jane K.
09 Oct 2021

Try this website - they make ear savers - you attach your mask to it so it attaches around the back of your head. And anti-fog nose-clips.

R A K.
09 Oct 2021
Hearing aids and glasses

I also initially had this problem. Working in the health field I have to wear a mask all day changing it every few hours. I have found that if I carefully put the elastic over my ears so they sit against my ear in front of the aids and glasses, when taking them off place fingers under elastic at my temples then gently slip my finger back over my ears the elastic comes away without getting tangled.
As to the article it would be helpful to know which makes were tested.