Disinfectant sprays are being used around the world to hose down plazas, church steps, airports, vehicles and even the occasional person. It’s part of the effort to stop the spread of COVID-19. But how effective is it? And is it something we should be doing here?
Workers wearing protective suits, rubber boots and tanks of disinfectant strapped to their backs have been photographed all over the world hosing down plazas, roads, church steps, airports, vehicles, indoor spaces and even the occasional person.
Some countries, such as Russia, Iran and Indonesia, have even used trucks to spray more areas more quickly.
And an industrial complex in Chongqing, China, has built “mist tunnels” to spray employees with disinfectant as they arrive for work.
The disinfectant is typically diluted bleach. And officially, it prevents the potential spread of COVID-19, the disease caused by the novel coronavirus.
Two tunnels at an industrial complex in China use spray mist to ‘disinfect’ people. 0:26
But are these methods effective? And is it something we should be doing here?
Disinfectants are effective against coronaviruses
It’s true that disinfectants effectively kill coronaviruses.
Coronaviruses are enveloped viruses, which means they are protected by an “envelope” made of lipids or grease that is easily dissolved by cleaners and leaves the virus itself vulnerable.
“This means they are one of the easiest types of viruses to kill with the appropriate disinfectant when used according to the label directions,” says Health Canada.
It recommends cleaning high-touch surfaces such as door handles and phones with either:
- Regular household cleaners.
- Diluted bleach (one part bleach to 50 parts water).
It has also published a list of disinfectants that are likely to be effective against COVID-19 on hard surfaces.
But… the virus can only be put on surfaces by people
While some diseases are spread by animals such as mosquitoes, COVID-19 can only be spread from people to other people, notes Tim Sly, a professor emeritus at Ryerson University’s School of Occupational and Public Health.
“It doesn’t exist in the environment,” he noted.
Respiratory viruses like coronaviruses are typically transmitted by droplets sprayed out when an infected person sneezes, coughs or, sometimes, just when they talk. In the case of coronavirus, it can even be spread by people without symptoms of the disease.
Those droplets can either land directly on surfaces or be transmitted to surfaces such as doorknobs if touched by an infected person, some of wh