[conspire] Good news on N95 mask reuse front

[Nick Moffitt]

On 24Mar2020 01:31am (-0700), Deirdre Saoirse Moen wrote:
> https://reddit.com/r/COVID19/comments/fo0rpe/stanford_researchers_confirm_n95_masks_can_be/
> 
> 70c/158f for 30 minutes
> 
> Deirdre

This ties into one of my favourite bits of trivia about boiling water: we boil water partly because we know once we see it boiling that it has hit 100°C, and that ensures all sorts of pathogens have died.

It turns out that the actual temperature we're aiming for is somewhere in the 65-70° range, as that's where a number of bacterial and viral structures break down.  It's just easier to spot a rolling boil than faff with laboratory-grade thermometers, and as a society we just pass on "boil water to kill germs" and job done.

It turns out this is one of the more difficult problems of low-cost widespread solar ovens: it's easy to get your food to 70° with bits of scrap, but you need a reliable thermometer to ensure that you haven't just created a 50° incubator for all the worst diseases in your area.  There are some prizes out there for determining this temperature range via inexpensive and available means, similar to the old "give us a way to determine longitude from the stars" one.  

Of course, the longitude question was suitable for a finicky technical solution, as it turned out.