[M T]

I reach into my freezer & take out a box of frozen beans that had been coughed on by someone that was sick 3 months earlier.

Then you're fine, the virus degrades after at most 72 hours.

You read this board, and I haven't made the effect of temperature clear enough?  Shame on me.

The recent correspondence that measured 3 days SURVIVAL was at room temperature (~72F), not at the Bay Area outside temperatures recently, at temperatures in the cargo hold of an airplane, and not at your refrigerator's or freezer's temperature.  Raise the temperature to 100 and the virus is inactivated quicker.  Keep it at a cooler temperature and it is active longer.

The recent report gave shorter survival times than other reports because it generally measured a drop of about 2 orders of magnitude for most of the surfaces, versus 3 orders of magnitude.  For instance, it reported a 3 day survival on plastic for SARS-CoV-1 while other reports measure up to 9 days.  Whether a drop of 2 orders of magnitude is enough presumably depends on the level of virus originally.  (Sort of a viral "Do you feel lucky, punk?" situation.)

Stop and think... What is special about freezing? Water freezes.  What has that to do with a virus?  Pretty much nothing.  If it is in a cell or in water, then maybe something.  But not if it is on a dry surface.  Coronaviruses have been shown to survive multiple rounds of dropping below freezing & warming up.

The virus is inactivated more quickly at higher temperature and higher humidity.  Conversely, it survives better at low temperature and low humidity.

This 2009 'Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces" is a source of info for the 2020 survey article.  Check out Figure 1 and Figure 2.  At 4 degrees C and 20% humidity, the two coronaviruses (not SARS-CoV-2) have dropped by maybe a factor 3 (ie, not much) at 28 days.  At higher humidity, the coronaviruses dropped more significantly (3 orders of magnitude). 

As concerning to me is that the report showed only a 2 orders of magnitude of drop at room temperature at 28 days, 20% RH for the two coronaviruses.
(At 50% and 80% RH, they hit 3 orders of magnitude drop at about 5 to 14 days.)  Somehow they seemingly were protected from inactivation.


Of course, no one has shown that you can get COVID-19 from a box of frozen vegetables that was coughed on by someone with the disease.  This is working from measurements and extrapolating them.

[M T]

I reach into my freezer & take out a box of frozen beans that had been coughed on by someone that was sick 3 months earlier.

Then you're fine, the virus degrades after at most 72 hours.

You read this board, and I haven't made the effect of temperature clear enough?  Shame on me.

The recent correspondence that measured 3 days SURVIVAL was at room temperature (~72F), not at the Bay Area outside temperatures recently, at temperatures in the cargo hold of an airplane, and not at your refrigerator's or freezer's temperature.  Raise the temperature to 100 and the virus is inactivated quicker.  Keep it at a cooler temperature and it is active longer.

The recent report gave shorter survival times than other reports because it generally measured a drop of about 2 orders of magnitude for most of the surfaces, versus 3 orders of magnitude.  For instance, it reported a 3 day survival on plastic for SARS-CoV-1 while other reports measure up to 9 days.  Whether a drop of 2 orders of magnitude is enough presumably depends on the level of virus originally.  (Sort of a viral "Do you feel lucky, punk?" situation.)

Stop and think... What is special about freezing? Water freezes.  What has that to do with a virus?  Pretty much nothing.  If it is in a cell or in water, then maybe something.  But not if it is on a dry surface.  Coronaviruses have been shown to survive multiple rounds of dropping below freezing & warming up.

The virus is inactivated more quickly at higher temperature and higher humidity.  Conversely, it survives better at low temperature and low humidity.

This 2009 'Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces" is a source of info for the 2020 survey article.  Check out Figure 1 and Figure 2.  At 4 degrees C and 20% humidity, the two coronaviruses (not SARS-CoV-2) have dropped by maybe a factor 3 (ie, not much) at 28 days.  At higher humidity, the coronaviruses dropped more significantly (3 orders of magnitude). 

As concerning to me is that the report showed only a 2 orders of magnitude of drop at room temperature at 28 days, 20% RH for the two coronaviruses.
(At 50% and 80% RH, they hit 3 orders of magnitude drop at about 5 to 14 days.)  Somehow they seemingly were protected from inactivation.


Of course, no one has shown that you can get COVID-19 from a box of frozen vegetables that was coughed on by someone with the disease.  This is working from measurements and extrapolating them.