[M T]

This suggests 72 hours max: https://hub.jhu.edu/2020/03/20/sars-cov-...-surfaces/

It's possible that lower temperatures slow it down, but probably not by a factor of 300. Also keep in mind that there's a large difference between "there's detectable virons at time t" and "you can get sick from the remaining virons at time t". The study suggesting 72 hours is actually the latter.

In fact, according to this exhaustively researched guide to covid food safety there haven't been any documented cases of transmission from surfaces. Is it possible? Sure. Is it likely? Not particularly.

And, really, that makes sense. People keep talking about how transmissible this is, but it's still 1 case leading to at most 3.5 more. If it could linger for days on surfaces and anyone who touched that same surface was getting sick, that number would be a lot higher. Transmission is by far the most likely from sharing close quarters, where you're guaranteed to be breathing in the carrier's exhalations.

Don't depend upon a derivative article.  Go back to the original research in the NEJM. 

Viruses were applied to copper, cardboard, stainless steel, and plastic maintained at 21 to 23°C and 40% relative humidity over 7 days.

Other research (which I referenced in another post here) indicates that at lower humidity, coronaviruses survive much longer, and that at lower temperature, coronaviruses survive much longer.

As for the "extensively researched guide" from SeriousEats, it writes

Temperatures and times for coronavirus are not yet fully researched, but scientists suggest a temperature of 149°F (65°C) for at least 3 minutes is sufficient.

but, if you follow the link in their guide, and read the research, you will see

At 65 °C, most of the virus was inactivated if incubated for longer than 4 min (Fig 2B). Again, some infectious virus could still be detected close to the limit of detection for the assay, after 20 min at 65 °C. While virus was incompletely inactivated at 56 and 65 °C even at 60 min, it was completely inactivated at 75 °C in 45 min (Fig 2[/url]C). Surprisingly, at both 56 and 65  °C the virus was inactivated at early time points but at 60 min a small amount of virus was detected.

I have to wonder where they got "3 minutes" from rather than 4 for those people who only want "most of the virus was inactivated", and why they didn't read the article they linked to when they say in that paragraph

Experts assume that the virus will respond like other pathogens and that hotter temperatures will require shorter times, but we currently do not have experimental data to prove it.

Another statement from SeriousEats that appears wrong is

According to multiple health and safety organizations worldwide, including [url=https://www.cdc.gov/coronavirus/2019-ncov/prepare/transmission.html]the CDC, the USDA, and the European Food safety Authority, there is currently no evidence that COVID-19 has spread through food or food packaging.

Follow that link to the CDC and you find

It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.

(The statement that transfer by hand is not thought to be the main way, then why so much emphasis on washing hands and deprecate wearing a mask, and advising that a mask is only useful when accompanied by frequent hand washing?)

I see no asterisk on "surface or object" to say  "unless that surface or object is food or food packaging".  So, why would it be excluded?  Or, was SeriousEats simply saying that there is no evidence for what the CDC says?

[M T]

This suggests 72 hours max: https://hub.jhu.edu/2020/03/20/sars-cov-...-surfaces/

It's possible that lower temperatures slow it down, but probably not by a factor of 300. Also keep in mind that there's a large difference between "there's detectable virons at time t" and "you can get sick from the remaining virons at time t". The study suggesting 72 hours is actually the latter.

In fact, according to this exhaustively researched guide to covid food safety there haven't been any documented cases of transmission from surfaces. Is it possible? Sure. Is it likely? Not particularly.

And, really, that makes sense. People keep talking about how transmissible this is, but it's still 1 case leading to at most 3.5 more. If it could linger for days on surfaces and anyone who touched that same surface was getting sick, that number would be a lot higher. Transmission is by far the most likely from sharing close quarters, where you're guaranteed to be breathing in the carrier's exhalations.

Don't depend upon a derivative article.  Go back to the original research in the NEJM. 

Viruses were applied to copper, cardboard, stainless steel, and plastic maintained at 21 to 23°C and 40% relative humidity over 7 days.

Other research (which I referenced in another post here) indicates that at lower humidity, coronaviruses survive much longer, and that at lower temperature, coronaviruses survive much longer.

As for the "extensively researched guide" from SeriousEats, it writes

Temperatures and times for coronavirus are not yet fully researched, but scientists suggest a temperature of 149°F (65°C) for at least 3 minutes is sufficient.

but, if you follow the link in their guide, and read the research, you will see

At 65 °C, most of the virus was inactivated if incubated for longer than 4 min (Fig 2B). Again, some infectious virus could still be detected close to the limit of detection for the assay, after 20 min at 65 °C. While virus was incompletely inactivated at 56 and 65 °C even at 60 min, it was completely inactivated at 75 °C in 45 min (Fig 2[/url]C). Surprisingly, at both 56 and 65  °C the virus was inactivated at early time points but at 60 min a small amount of virus was detected.

I have to wonder where they got "3 minutes" from rather than 4 for those people who only want "most of the virus was inactivated", and why they didn't read the article they linked to when they say in that paragraph

Experts assume that the virus will respond like other pathogens and that hotter temperatures will require shorter times, but we currently do not have experimental data to prove it.

Another statement from SeriousEats that appears wrong is

According to multiple health and safety organizations worldwide, including [url=https://www.cdc.gov/coronavirus/2019-ncov/prepare/transmission.html]the CDC, the USDA, and the European Food safety Authority, there is currently no evidence that COVID-19 has spread through food or food packaging.

Follow that link to the CDC and you find

It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.

(The statement that transfer by hand is not thought to be the main way, then why so much emphasis on washing hands and deprecate wearing a mask, and advising that a mask is only useful when accompanied by frequent hand washing?)

I see no asterisk on "surface or object" to say  "unless that surface or object is food or food packaging".  So, why would it be excluded?  Or, was SeriousEats simply saying that there is no evidence for what the CDC says?