Can a cooking staple stop the coronavirus?
On Feb. 5, Canada’s CTV News reported that researchers at the University of Alberta have developed a virus-killing salt coating that’s designed to improve the effectiveness of common surgical masks often used to prevent the spread of pathogens like influenza or the novel coronavirus.
“The sodium chloride coating applied to the surface of the surgical mask is designed to kill any virus particles,” said Choi during an email interview with the JoongAng Ilbo on Sunday.
According to Choi, when virus-carrying water droplets sit on the surface of the salt-coated mask, the salt dissolves and the water begins to evaporate. During the evaporation process, the salt crystals begin to grow and the very sharp edge of the crystal basically destroys the virus.
Choi’s team has tested the coating on three different influenza viruses, all of which became inactive within 30 minutes of being exposed to the sodium chloride.
Choi and his team have been working on salt-coated masks since 2015, and a paper including their initial findings was published in the International Journal of Scientific Reports in 2017.
“We’ve been discussing with other countries including China testing the coating on the novel coronavirus,” Choi said. “A decision about choosing our partner country will be made by this week. Since the novel coronavirus has a similar morphology to the viruses we tested, we believe it’ll work.”
Choi also emphasized that, “as viruses are constantly mutating,” humans should “never stop their research and must always be ready.”
Choi, who studied ceramic engineering as an undergraduate and graduate at Yonsei University, western Seoul, received his doctorate degrees in biotechnology engineering from the University of California, Los Angeles. Choi has been working at the University of Alberta since 2015.
Below are edited excerpts of the interview.
Q. Why are you focusing more on developing masks instead of a vaccine?
A. Our team’s major work is to come up with defense solutions against global pandemics and epidemics. Developing vaccines is also part of our works. However, it takes at least six months to develop vaccine products. In the absence of a cure or vaccine, respiratory protective equipment such as masks are the only way to protect humans from diseases.
When will the salt-coated masks be commercially available?
We are already done with developing the salt coating, which is the core point of our product. If we layer these coatings three times, then it becomes a mask. All examinations including environmental safety for the mask are done as well. Since we are in active discussion with government agencies and many different companies, the masks are expected to be manufactured in the next 12 to 18 months. The salt-coated masks are able to destroy not only the virus from droplets but also from aerosol particles.
How did you come up with the idea?
As there are many types of salt, when it dissolves in water, salt crystals can form in many different shapes. Those crystals can destroy different types of viruses, even their mutated forms, depending on the types of salt and shapes that are formed. Also, the salt-coated mask is reusable as its efficiency won’t deteriorate although recrystallization occurs from melted salt. In addition, salt is cheap and safe even when it is coated.
Can wearing masks fully protect people against viruses?
A surgical mask provides a physical barrier to fluids and large particle droplets, but not small droplets released into the air. The World Health Organization recommends the use of N95 masks that can block at least 95 percent of 0.3-micron particles. However, the actual size of virus particles is usually less than 0.1 micron. Also, a virus can live on the surface of a mask for up to a few weeks depending on the circumstances. As humans have the tendency to touch their faces every four minutes, they are at risk of contracting the virus. Also, the virus particles on the surface of the mask can be released into the air and infect others. This is the reason why people should wear disposable masks and never reuse them. In order to reduce this kind of risk of cross infections, our product aims to destroy the virus completely.
Why did the mask take so long to develop?
It took a long time for us to develop the salt-coated mask as it was a new concept that others had never tried before. In the beginning, only two people, my friend and I, started the research. But after we realized that it was going to be larger scale research than we initially thought, we invited 10 more researchers and four professors from different universities. In 2007, we once asked a few companies including one of the biggest companies in Korea for their cooperation for a speedy end to the research, but they rejected us. Fortunately, the Natural Sciences and Engineering Research Council of Canada, Mitacs [a nonprofit national research organization in Canada] and the University of Alberta supported us financially.
BY LIM SUN-YOUNG, CHEA SARAH [firstname.lastname@example.org]