[M T]

OK, now I'm confused:

https://www.newsweek.com/coronavirus-hea...us-1498074

Confusion is what one gets when one listens to the media, and then applies logic to what you're told.   From the Yahoo coverage of the unseen government lab report, we don't know how quick "quickly" is, how high "high temperature" is, or how destroyed "destroyed" is.

The Newsweek article has a link to the actual report.  First thing I notice is that they are actually working to a standard. About time. And they are reducing the levels of virus by 6 orders of magnitude, so a million-fold.   AND they are reporting how long to get to that point, not some point arbitrarily short of that point.

Remember the report in early March that said something about 3 days on plastic and 24 hours on cardboard?  What it really said was to get a TWO orders of magnitude reduction in virus, you needed to wait 4 days on plastic and 48 hours on cardboard.  (Their criteria was from some arbitrary starting concentration of virus, and deciding it was enough when their test wasn't sensitive enough to detect any.  For a few tests, that was a bit over 3 orders of magnitude, but IIRC most tests were a reduction of two orders of magnitude.)

Then it was reported as "The virus is still alive after 3 days on plastic and 1 day on cardboard".  They did show that, as well as showing the virus was still active after 1 day on plastic and 6 hours on cardboard.    It wasn't until 4 days had elapsed that the virus was below their instrument's sensitivity on plastic. 2 days on cardboard.

This new study is setting a much higher bar, a million-fold reduction in viral levels.  If you want to be really sure you don't have much virus left, to get from a 2-log drop to a 6-log drop, triple the time involved. One could expect the virus to reach a 6-order of magnitude drop on plastic around day 12 (3 * 4), based on the earlier result.  For cardboard, it would be about 6 (= 3*2) days.  That's at room temperature & normal humidity (40-60% RH, I believe).

The report referenced by Newsweek reported on times that it took to achieve this level of reduction at temperatures of 30min@56C, 60min@60C, and 15min@92 degrees C.    The first two were  >5-log reductions; the last was >6-log.    These kinds of times are consistent with what was reported in 2009 for coronaviruses.

Oh, by the way, regarding humidity and viruses: The role humidity plays for inactivating viruses seems to be all over the map. Different effects at different temperatures, etc.

[M T]

OK, now I'm confused:

https://www.newsweek.com/coronavirus-hea...us-1498074

Confusion is what one gets when one listens to the media, and then applies logic to what you're told.   From the Yahoo coverage of the unseen government lab report, we don't know how quick "quickly" is, how high "high temperature" is, or how destroyed "destroyed" is.

The Newsweek article has a link to the actual report.  First thing I notice is that they are actually working to a standard. About time. And they are reducing the levels of virus by 6 orders of magnitude, so a million-fold.   AND they are reporting how long to get to that point, not some point arbitrarily short of that point.

Remember the report in early March that said something about 3 days on plastic and 24 hours on cardboard?  What it really said was to get a TWO orders of magnitude reduction in virus, you needed to wait 4 days on plastic and 48 hours on cardboard.  (Their criteria was from some arbitrary starting concentration of virus, and deciding it was enough when their test wasn't sensitive enough to detect any.  For a few tests, that was a bit over 3 orders of magnitude, but IIRC most tests were a reduction of two orders of magnitude.)

Then it was reported as "The virus is still alive after 3 days on plastic and 1 day on cardboard".  They did show that, as well as showing the virus was still active after 1 day on plastic and 6 hours on cardboard.    It wasn't until 4 days had elapsed that the virus was below their instrument's sensitivity on plastic. 2 days on cardboard.

This new study is setting a much higher bar, a million-fold reduction in viral levels.  If you want to be really sure you don't have much virus left, to get from a 2-log drop to a 6-log drop, triple the time involved. One could expect the virus to reach a 6-order of magnitude drop on plastic around day 12 (3 * 4), based on the earlier result.  For cardboard, it would be about 6 (= 3*2) days.  That's at room temperature & normal humidity (40-60% RH, I believe).

The report referenced by Newsweek reported on times that it took to achieve this level of reduction at temperatures of 30min@56C, 60min@60C, and 15min@92 degrees C.    The first two were  >5-log reductions; the last was >6-log.    These kinds of times are consistent with what was reported in 2009 for coronaviruses.

Oh, by the way, regarding humidity and viruses: The role humidity plays for inactivating viruses seems to be all over the map. Different effects at different temperatures, etc.