COVID-19: Can glasses protect you? How long can microbes survive on surfaces?
Find out how SARS-CoV-2 fares on common household appliances, laptop, toilet paper, glasses, money and even the packages delivered to your door.
There are some very good reasons for being fastidious with your cleaning and disinfecting efforts these days (yes, these are two very different steps). We are, after all, still in a pandemic.
Even though the experts at the Centers for Disease Control and Prevention (CDC) in the US say SARS-CoV-2, the virus that causes COVID-19, is primarily passed through respiratory droplets, they haven’t ruled out the possibility of getting infected through contact with surfaces either.
According to the CDC, SARS-CoV-2 isn’t detected on non-porous surfaces such as stainless steel, plastic and glass beyond 72 hours or three days. On porous surfaces such as cardboard and paper, the virus stays even shorter – within minutes to hours.
Experts said that the shorter duration could be that porous surfaces allow respiratory droplets containing the virus to evaporate faster and leave the surface.
So, where does that leave us? It may be useful to know what surfaces at home need more careful or more frequent disinfecting.
To help with that, studies published in the New England Journal Of Medicine (NEJM) and The Lancet have delved into just how long the virus can live on different surfaces at room temperature.
The NEJM study applied a standardised amount of aerosolised virus to different surfaces, while The Lancet study placed a drop containing the virus on each surface.
Here’s a look at how long the virus survived on each surface – and what advances in science can keep them at bay:
Examples: Computer accessories, such as keyboard and mouse, remote controller, video game controller, light switches, food packaging, kitchenware, money and credit cards.
Research: The virus was detected on plastic for up to three days, according to the NEJM article. Researchers in the Lancet study, however, could still find the virus on plastic for much longer: Up to seven days.
Antimicrobial action: While it’s not clear by how much antimicrobial coatings can shorten the virus’s survivability on plastic surfaces, these coatings have been found to keep the nasties at bay for 90 days with just one application.
That’s at least according to the research by the University of Arizona, which pitted such a coating against a human coronavirus that is structurally and genetically similar to SARS-CoV-2 but safer to test with.
Examples: Door handles, refrigerator, cookware, cutlery, coins and keys.
Research: Like plastic, the virus lasted all of three days on a stainless-steel surface in the NEJM study, but in The Lancet, it was still viable for up to seven days.
Copper is a better bet against SARS-CoV-2. Researchers in the NEJM study found the virus less stable on copper and no viable virus was detected after just four hours.
Antimicrobial action: The antimicrobial properties of copper and its alloys (such as brass and bronze) are the reason why the metal is frequently and historically used in high-touch points such as the Grand Central Station’s century-old hand rails in New York.
Copper is also used to protect ships’ hulls from barnacles and mussels. It is even used by French wine-makers to stop fungal attack on their vines.
Examples: Spectacle lenses, screens of TVs, laptops and handheld gadgets, windows and mirrors.
Research: It took four days for the virus to leave the glass surface, according to The Lancet article.
Antimicrobial action: If glass can potentially be a conduit for coronavirus, should you ditch the glass lenses in your spectacles for contact lenses? That’s not necessary, according to the American Academy of Ophthalmology (AAO).
Spectacles could serve as a reminder not to touch your eyes and also, partially shield them from the splatter of a cough or sneeze, said ophthalmologist Dr Thomas Steineman on the AAO website. However, he didn’t see the need to wear spectacles or eye masks for protection.
For those who work in healthcare or are just more cautious, some lenses are coated with an antimicrobial layer such as the Zeiss DuraVision AntiVirus UV layer, which can purportedly kill 99.9 per cent of viruses and bacteria that come into contact with the glass’s surface.
Examples: Tissue, toilet paper, paper towels, books, newspapers and stationery.
Research: According to The Lancet study, no viable virus was found on printing paper or tissue after three hours. The NEJM study noted that no viable virus could be detected on cardboard after 24 hours.
Antimicrobial action: Dr Elizabeth Scott, a microbiology professor at Simmons University’s Simmons Center for Hygiene and Health in Home and Community, recommends opening your packages outside your apartment or on the floor.
Opening your package on the counter or kitchen table can cause you to touch more of the box’s surface with your hands.
Examples: Shelves, doors, furniture and cutlery.
Research: Compared to non-organic materials such as plastic, wood seems to shake off the virus quicker – two days versus plastic’s maximum duration of seven days, according to The Lancet study.
Antimicrobial action: This could be due to the microstructure of wood and the presence of antimicrobial substances in it, said researchers from the University of Natural Resources and Life Sciences in Vienna.
In fact, to further lower the risk of COVID-19 transmissibility, they recommended “quarantining” the wood product for a week.
When using a disinfectant on wood, make sure it doesn’t contain alcohol as it can strip the varnish and damage the surface.