The scientists then investigated how long the virus remained infectious on these surfaces, according to the study that appeared online in the New England Journal of Medicine on Tuesday.
The tests show that when the virus is carried by the droplets released when someone coughs or sneezes, it remains viable, or able to still infect people, in aerosols for at least three hours.
On plastic and stainless steel, viable virus could be detected after three days. On cardboard, the virus was not viable after 24 hours. On copper, it took 4 hours for the virus to become inactivated.
In terms of half-life, the research team found that it takes about 66 minutes for half the virus particles to lose function if they are in an aerosol droplet.
That means that after another hour and six minutes, three-quarters of the virus particles will be essentially inactivated but 25 per cent will still be viable.
The amount of viable virus at the end of the third hour will be down to 12.5 per cent, according to the research led by Neeltje van Doremalen of the NIAID’s Montana facility at Rocky Mountain Laboratories.
On stainless steel, it takes 5 hours 38 minutes for half of the virus particles to become inactive. On plastic, the half-life is 6 hours 49 minutes, researchers found.
On cardboard, the half-life was about three and a half hours, but the researchers said there was a lot of variability in those results “so we advise caution” interpreting that number.
The shortest survival time was on copper, where half the virus became inactivated within 46 minutes.
As of Tuesday afternoon, only people who have recently travelled from overseas or have been in contact with a confirmed COVID-19 case and experienced symptoms within 14 days are advised to be tested.
If you believe you may have contracted the virus, call your doctor, don’t visit, or contact the national Coronavirus Health Information Hotline on 1800 020 080.
If you are struggling to breathe or experiencing a medical emergency, call 000.