On November 24, 2021, the administrative quarantine system at the New Zealand border is being dismantled for use by fully vaccinated New Zealanders. Starting early next year, travelers will be able to bypass it. Officials announced that there were 215 cases of Covid-19 today.

Liu Chen for RNZ

A group of New Zealand researchers said that disposable masks, washed and worn again, are still better protected than three-layer cloth masks.

The study concluded that disposable masks can be washed 10 times in a washing machine, which is still better than three-layer cotton.

On the streets of central Auckland, many people chose cloth masks instead of disposable masks, including Nora, who wore a mask dotted with colorful flower patterns.

"You don't need to waste [masks] all the time. You don't have to throw away [them], it is very stylish and very cute," she said, adding that it is also more comfortable.

Richard Everts, a microbiologist at Nelson, said that seeking comfort rather than protection is a "wrong benefit" because some fabric masks have very thin layers and may not fit.

The person in charge of the research project said that the performance of disposable commercial medical masks is the result of decades of research.

"We found that commercial masks, even if you wash them 10 times, are better than fabrics-even if you have three layers of fabric, one on top of the other, commercial masks are still better."

Evertz said his team obtained several brands of disposable medical masks and fired Covid-sized particles into the fabric.

They found that the new medical masks can block up to 98% of the particles. Then they clean them in eight different ways-the most demanding is in the washing machine, or using detergent, soap or bleach.

After using these deep cleaning methods for 10 consecutive washings, the disposable mask still filtered out about half of the particles.

Everts explained how to clean disposable masks.

"The best method involves removing all biological materials with water, preferably warm or hot water, because this will remove bacteria and viruses and kill them, and then you have to let it dry. Drying will kill any viruses that are still there. Most bacteria."

The researchers then fired particles at a single layer of fabric (such as cotton). Washed or unwashed-the result is the same-cotton only blocks 10% of the particles. When there are three layers, the material still only reaches 40%.

Lucy Telfar Barnard, a senior researcher at the University of Wellington, Otago, also participated in the mask research.

She said that in a medical environment, disposable masks should be discarded after the first use, but for ordinary consumers, it is safe to wash and reuse them. She said this is also a more environmentally friendly method.

"I definitely recommend people to clean disposable masks. Just discarding them will have an impact on the environment. They are usually made of synthetic materials, so they take a while to decompose," she said.

Barnard said that a well-fitting mask is as important as the material.

"It's the combination of fit and filter that really works. If your mask doesn't fit, then it really reduces its effectiveness."

Professor Michael Baker, an epidemiologist at the University of Otago, said that many masks on sale do not meet the standards and should be banned. He said that a national mask strategy is needed, which should cover two areas.

"The first is to clearly guide which masks to use, when to use them, and where to use them. The second is to formulate national standards for masks to let everyone know when to buy masks. Commercial advertisements, such as fabrics, masks, and reusable masks, you will Knowing that it is suitable for use."

Baker said that it should also be clear which standards need to be met by homemade masks.