The novel coronavirus that causes Covid-19 can remain infectious on face masks for up to a week, South China Morning Post reports according to a study.
The study, conducted by researchers from the University of Hong Kong (HKU), also suggests the virus lasts on banknotes, stainless steel, and plastic surfaces for days.
The researchers also found that common household disinfectants, including bleach, were effective in “killing” the virus.
The report, published in The Lancet journal, adds to a growing body of research about the stability of SARS-CoV-2 - as the novel coronavirus is formally known - and what can be done to prevent its transmission.
"SARS-CoV-2 can be highly stable in a favourable environment, but it is also susceptible to standard disinfection methods," said the researchers, including Leo Poon Litman and Malik Peiris, both from HKU's School of Public Health.
The researchers tested how long the virus could remain infectious at room temperature on a variety of surfaces.
On printing and tissue paper it lasted less than three hours, while on treated wood and cloth, it had disappeared by the second day.
On glass and banknotes, the virus was still evident on the second day, but had gone by the fourth, while on stainless steel and plastic it was present for between four and seven days.
"Strikingly," the researchers said, there was still a detectable level of infection on the outer layer of a surgical face mask after seven days.
"This is exactly why it is very important if you are wearing a surgical mask you don't touch the outside of the mask," Peiris said.
"Because you can contaminate your hands and if you touch your eyes you could be transferring the virus to your eyes," he was quoted by the South China Morning Post.
On all surfaces, the concentration of the virus reduced quite rapidly over time, the study said.
A study by the US researchers on the environmental stability of the coronavirus published last month in the journal Nature also concluded that it can remain infectious on some surfaces for days.
They found the virus was present on plastic and steel for up to 72 hours, but did not last more than four hours on copper or 24 hours on cardboard.
The findings from HKU add to the conversation about public health and hygiene, and what kinds of precautions people should take when bringing items like groceries into their homes.
