As the number of infected cases of coronavirus rises, numerous countries are facing a massive shortage of masks

As a result, there've been some uncertainty as to whether such masks can or cannot be reused.

This uncertainty was met with claims that masks can be steamed and subsequently re-worn.

Video claims masks can be steamed and re-worn

A video of a purported doctor advising people on how to reuse their masks went viral, and was posted to numerous Chinese social media sites including Weibo and Youku.

The rather dubious video contains instructions on how to steam disposable masks, asking viewers to "sterilise the mask for 10 minutes with steam at 100°C".

An alleged doctor, who the video claims is an infectious disease specialist named Wu Meng, then states that a mask can be reused up to five times as long as it has not been worn in high-risk locations.

Experts say claim is misleading

Experts however, have since come forward to debunk these claims.

An adviser at Hong Kong's Centre for Health Protection, Wong Ka-hing, stated that surgical masks should only be used once, the city's government-owned broadcaster RTHK reported.

The centre had also released graphics discouraging people from steaming and reusing masks, stating that "used surgical masks are contaminated with pathogens and must be dumped in a covered bin."

The graphic added that the efficacy of the masks would be affected when wet.

This sentiment is echoed by Dr. Leong Hoe Nam, an Infectious Disease Specialist at Mount Elizabeth Hospital, who said that masks should be discarded when wet.

A World Health Organisation advisory also discourages people from reusing single-use masks, and to discard masks when they become damp or humid.

Additionally, masks can trap dirt and bacteria within, and once used, would be contaminated with the user's and other's secretions and saliva. This could lead to self-inoculation, reported AFP.

One expert compared masks to tissues, which are single-use. "Just like tissue papers which are meant to be single-use items. If you sneeze onto a tissue paper, it is soiled. You won't ask people to steam it, air dry it and re-use it a second or a third time," he said.

Steaming the masks could also damage the filter and reduce the mask's efficiency.

Top photo from Weibo and Sing Tao Daily