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  • Welcome to the new site. Here's a thread about the update where you can post your feedback, ask questions or spot those nasty bugs!

A Guide to Survival of Infectious COVID-19 on Various Surfaces

Asher Kelman

OPF Owner/Editor-in-Chief
This is a good authoritative reference.

3964

Note that simply wiping down a surface with soapy water lifts the virus from the surface and the fatty capsize outer shell dissolves essentially exploding the virus. Rinsing off then renders the surface safe.

Supermarkets are now disinfecting the sales counter. But hundreds of folk pass through and therefore assume some goods are infected.

So when receiving groceries,

1. wear gloves, assume anyone is is a silent infected person, shedding virus so wear gloves and keep your distance.

2. Leave paper wrappings outside.

3. Store non perishable good for 48 hours outside, say in a garage. Don’t refrigerate produce isn’t washed in soapy water. M

4. Refrigeration could protect surface virus on produce or containers for many days.

5. Glass and plastic as well as milk cartons can be easily washed down with soap before refrigeration.

6. When unpacking produce, wear gloves, divide table/counter top into a sterile area and a receiving potentially contaminated area.

7. Produce arrives in the receiving area, gets washed down in sink and then placed on clean area

At end clean down both areas with soap and water and then with a dilute bleach solution and then remove and store gloves.

No need to use sanitizer unless out of the house! Soap is 100% effective if used as instructed above.

Asher
 

Asher Kelman

OPF Owner/Editor-in-Chief
Thank you @Asher Kelman !
How long the virus will stay "alive" on the clothes?
Consider them like cardboard or plastic. But remember that this is a “half-life”, so that it depends on the starting dose. The initial droplet coukd have 1,000 dose or 2 doses in it. The “half life” is the time in which the Infectious dose degrades by 50%.

So one must actually clean clothes that are suspected of having made contact with the virus. That is why first responders, (nurses and doctors at high risk), wear disposable garments.

Asher
 

nicolas claris

OPF Co-founder/Administrator
Thank you Asher, but how "half-life” can be relevant?
What would be interesting is when the virus cannot be anymore dangerous! No?
 

Asher Kelman

OPF Owner/Editor-in-Chief
Thank you Asher, but how "half-life” can be relevant?
What would be interesting is when the virus cannot be anymore dangerous! No?
If a rabbit jumps each time half the distance to the tree, how many times does he need to jump to reach the tree?
 

Asher Kelman

OPF Owner/Editor-in-Chief
The only time “half-life” doesn’t apply is when we use some agent to permanently distort, unravel or disrupt the intact virus structure:

  1. chlorine
  2. High dose UV irradiation
  3. Soapy water
  4. Heat: prolonged
  5. Caustic chemicals: acids, alkali’s
  6. dilution in washing


Asher
 

nicolas claris

OPF Co-founder/Administrator
Thanks!
I've heard that white vinegar diluted with water is effective for cleaning surfaces... Does that make sense?
 

Jerome Marot

Well-known member
This is all well said, but the virus decay times were measured in laboratory conditions. Statistics on infections do not show a correlation with objects but with people.

I am probably talking way above my competences here, but we all are as none of us is an epidemiologist. So please take my advice with common sense. What do I mean?

What I mean is that:
  • if you are at a particularly high risk, as in "living under immunosuppressants", please continue to disinfect everything
  • if not, the risk of being infected by objects is probably negligible. I mean: clean everything if you feel like it, but your priorities should be people. Just don't go less than 2-3 meters to anyone, unless that person wears a face mask (any mask) or you wear a proper face mask (meaning of the kind you probably can't buy now).

The quarantine is hard enough as it is, please don't make it any harder on yourself.

As to disinfectant, I use glass cleaning fluid on hard surfaces. It is cheap, comes in a spray bottle and is formulated to remove greasy stuff, which is just what COVID-19 does not like.
 

Asher Kelman

OPF Owner/Editor-in-Chief
Jerome,

Your points on people are spot on.

However, the risk of virus spread from surfaces is very real as we touch things frequently and the. Touch our nose mouth and eyes repeatedly throughly an hour, easily short enough to get infected.

Here I talk as a PH.D. Professor of Microbiology, an expert in Virus production and having trained over a thousand doctors with safety procedures and trained masters and Ph.D. Students in also working with 10 to the 11th dose of dangerous viruses routinely without a single person getting infected.

What I say is what is also recommended by experts in the USA.

We do not know enough even about airborne transmission, but it does seem now that coughing is not needed, just close contact and conversation.

Japanese in packed in trains have not caused infection explosions as they wear masks and done chat!

We suspect, (but don’t know yet), that merely touching a contaminated surface is a real source of transmission, just like smallpox, which was transmitted to Native Americans in contaminated donated blankets or anthrax by contact with powder which then gets in the mouth or breathed in.

This COVID virus is unusually hardy.

In an air conditioned environment surface contamination will last longer.

When it gets warmer don’t use the air conditioner, if feasible!
 

Jerome Marot

Well-known member
However, the risk of virus spread from surfaces is very real as we touch things frequently and the. Touch our nose mouth and eyes repeatedly throughly an hour, easily short enough to get infected.

I am not disputing that it is possible to transfer pathogens (generally) in this manner, as this is a documented fact. I am noting that, from what we know from countries like South Korea and Japan, the risks from this kind of transmission for COVID-19 specifically appears to be low. If it were high, neither South Korea nor Japan would have managed to lower the R0 to present levels without a complete lockdown and without disinfection measures for shops, parcels, etc... Yet they have and can trace infections to contact persons, which points to a relatively low risk for surface transmission.

We are actually talking about different things. Virus activity on surfaces, known pathways of infection for pathogens (generally) and observed statistics on a population of millions. All of this is good science, but measures completely different variables.

We do not know enough even about airborne transmission, but it does seem now that coughing is not needed, just close contact and conversation.

Japanese in packed in trains have not caused infection explosions as they wear masks and done chat!

I certainly agree to that. I think I am the person that first posted about the case of Japan on this forum and what it teaches us as to contamination. There is however a slight correction needed: apparently, in Japan people do not talk to each other when using public transport. So all what we know from Japan is that transmission in a low ventilated area (a train) full of people wearing masks and not talking to each other is low.

In an air conditioned environment surface contamination will last longer.

When it gets warmer don’t use the air conditioner, if feasible!

There again we don't know by which mechanism contamination may be higher in air conditioned areas. As far as I know, it is not even clear that such is the case, the hypothesis has been advanced to explain contaminations in Singapore and Hong Kong, but to my knowledge the data is not conclusive. I could try to look it up.

This being said, air conditioners are known to be great devices to spread pathogens around as they move air and let it go through surfaces where humidity and dust mix to the equivalent of a Petri dish. It stands to reason that they increase the risks.
 

Jerome Marot

Well-known member
Ok, but what about the airborne spread of the virus? And its lifespan?

We simply do not know. I am having this discussion with several people in Munich and I think it is important that we realise the limitations of science, our data and what a particular scientific paper actually means. For example, we can measure the presence of the virus on surfaces and we know pathways to infections. But we cannot measure whether a particular pathway is actually used by this particular virus. If we wanted to measure that, we would need to actually try to infect a statistically significant number of people by this method and we can't do that for obvious reasons. So we have to resort to statistics, which work quite well when they are applied to a country of several millions, but don't give us facts, just probabilities. And statistics are slow, they can only tell us about things after they have happened.

It is the same for airborne infections. We know they are a main pathways, because millions got sick in that way. We will know whether airborne infections are dependent on temperature or solar UV, when we have the figures in tropical countries without air conditioning, which will take another month. We can make hypothesises about increased airborne transmission du to atmospheric pollution (NOx and particulates) as the two areas with the largest number of deaths suffer from this kind of pollution, but it is only an hypothesis. We don't know.
 
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