As we all know, people can catch covid-19 by touching door knobs, light switches, faucet handles, payment screens in stores, etc., and then touching their faces. This is why we should wash our hands frequently and avoid touching our faces. Sometimes it’s even a good idea to wear disposable rubber gloves.
So there’s no question that the virus can survive on objects and that we can get infected from touching those objects.
But do we need to worry about delivered packages and items we buy in stores? If we order something from Amazon and the UPS driver leaves it on our porch, do we need to be concerned about touching the box? What about the items inside the box? What about food?
The answer is yes, in some cases we need to be concerned. The CDC says we don’t but I just read the following paper — it’s new — and I think the CDC is wrong:
Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1
Also see this preprint published a few weeks later:
Stability of SARS-CoV-2 in different environmental conditions
These scientists found that at room temperature, the covid-19 virus lived up to 72 hours on plastic and stainless steel, 24 hours on cardboard, and 4 hours on copper.
Temperature is significant because it’s almost certain that the virus lives longer when temperatures are lower, as suggested by the following papers:
Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces
Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents
Suppose a UPS driver leaves a cardboard box on your porch. You might think, “I’ll leave it here for 24 hours, and then it will be safe to handle.” Not necessarily. If it’s cold outside, the virus might live longer than 24 hours.
And what about a milk carton that stays refrigerated from the moment it leaves the bottling plant? According to the research cited above, some viruses can live more than 28 days at that temperature. Maybe SARS-CoV-2 can too. We don’t know yet.
Coming soon: how to disinfect things.
How to Handle Packages During the Coronavirus Pandemis
This article, published on a website owned by the New York Times, is typical of the bad advice being given to the public by official agencies and big media companies. Actually it’s a little better than most. I urge you to remember as you read it: (1) Just because a risk is low doesn’t mean we shouldn’t bother to avoid the risk; (2) Just because one team of scientists measured the lifetime of a virus on cardboard, doesn’t mean their results apply to all types of cardboard in all humidities at all temperatures; and (3) When you receive a shipped package, not only the exterior of the box but also the items inside, may be contaminated.
Many people are making this mistake about the pandemic (March 28, 2020)
Covid-19 is now clearly visible in flu/pneumonia stats (March 27, 2020)
What Hannity should have asked Trump (March 27, 2020)
Greg Cochran doesn’t suffer fools gladly (March 27, 2020)
The United States is on a uniquely dreadful trajectory (March 26, 2020)
That didn’t take long (March 23, 2020)
How to disinfect packaged food (March 21, 2020)
US covid-19 cases are now showing up in statistics (March 20, 2020)
How to disinfect fruits and vegetables (March 17, 2020)
An email conversation between a friend and me (March 15, 2020)
Why don’t US covid-19 cases show up in flu/pneumonia stats — or do they? (March 14, 2020)
The next president of the United States will not be Donald Trump or Joe Biden or Bernie Sanders (March 14, 2020)
Can I catch covid-19 from boxes, objects from the store, letters, etc? (March 12, 2020)
Fatality rates will be different in different European countries, and here’s one reason why (March 10, 2020)