A new study on the COVID-19 virus has found that it lasts up to three hours in air and for two-three days on surfaces. The study, led by US government’s National Institutes of Health (NIH) and Rocky Mountain Laboratories in Hamilton, Montana, conducted some of the first tests of how long COVID-19 virus lasts for on different surfaces.
The study shows that the virus could survive in droplets for up to three hours after being coughed out into the air. Fine droplets between 1-5 micrometres in size – about 30 times smaller than the width of a human hair – can remain airborne for several hours in still air. It found that the COVID-19 virus survives longer on cardboards, which can persist up to 24 hours. On plastic and stainless steel surfaces it can last for two to three days, meaning the virus might last this long on door handles, plastic-coated or laminated worktops and other hard surfaces. However, on copper surfaces, the virus tends to be killed off at around four hours only. For clothing and other surfaces, however, the scientists need more tests on how long the virus will last due to the nature of the surface.
Vincent Munster, head of the virus ecology section at Rocky Mountain Laboratories, and one of the leads of the NIH study, said, “We speculate due to the porous material, it desiccates rapidly and might be stuck to the fibres. [We’re] currently running follow-up experiments to investigate the effect of temperature and humidity in more detail.”
The ability of the virus to linger for so long only underlines the importance of hand hygiene and cleaning of surfaces, according to Munster.
The quickest way to prevent the spread of the virus within a minute is by disinfecting surfaces with 62-71 per cent alcohol, or 0.5 per cent hydrogen peroxide bleach or household bleach containing 0.1 per cent sodium hypochlorite.
The research has shown that higher temperatures at about 56°C or 132°F can kill off the coronavirus strain. The rate would be about 10,000 viral particles for every 15 minutes.