The new coronavirus COVID-19 that caused already a global pandemic can remain viable and infectious in droplets in the air for hours and on surfaces up to days, Reuters reports.

These are the main findings of a new study of scientists from the National Institute of Allergy and Infectious Diseases (NIAID), part of the U.S. National Institutes of Health. The research was led by Neeltje van Doremalen of the NIAID’s Montana facility at Rocky Mountain Laboratories.

Results appeared online in the New England Journal of Medicine this week.

How long does the virus remain infectious on different surfaces?

The team used a device to dispense an aerosol that duplicated the microscopic droplets created in a cough or a sneeze. The scientists then investigated how long the virus remained infectious on these surfaces.

Our data consisted of 10 experimental conditions involving two viruses (SARS-CoV-2 and SARS-CoV-1) in five environmental conditions (aerosols, plastic, stainless steel, copper, and cardboard). All experimental measurements are reported as means across three replicates", announced the team.

In aerosols for at least 3 hours,  on plastic and steel - 3 days

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.

The shortest survival time was on copper

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% will still be viable.

The amount of viable virus at the end of the third hour will be down to 12.5%. 

The shortest survival time was on copper, where half the virus became inactivated within 46 minutes.

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.

Read the whole study HERE