Author Topic: Electrostatic foggers for bulk decontamination  (Read 1943 times)

ergophobe

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Re: Electrostatic foggers for bulk decontamination
« Reply #15 on: June 23, 2020, 05:47:39 AM »
Remember that foggers have a lot more aerosolization than electrostatic sprayers. The spray is not ionized, so it isn't attracted to grounded surfaces and therefore stays in the air a lot longer, while at the same time covering less effectively, because it's not drawn back to the back side of the object in the same way.

I think they also require more extensive protective gear because they do aerosolize the product, rather than creating a spray.

Electrostatic sprayers are either super expensive or very hard to find. The Protexus (which is just like the Victory, but white) is featured in all the Marriott ads. I think Marriott has cornered the market. They are safer and more effective though.

In anycase, I think it's way more important to open the windows and turn on a fan than to spray down the house. It's the aerosols, not the surfaces, that matter and you want to get those evacuated or settled and dried, ideally before the cleaner enters. Listen to this interview with Michael Osterholm, founder and director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

https://www.npr.org/2020/06/17/879255417/amid-confusion-about-reopening-an-expert-explains-how-to-assess-covid-risk

In our area, cleaners are prohibited from entering a hotel room or other lodging for 24 hours after people check out. Then all linens, dishes, pots and pans, utensils, et cetera must be washed, whether they have been used or not. Not possible in five hours unless you have access to a linen service.

Rupert

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Re: Electrostatic foggers for bulk decontamination
« Reply #16 on: June 23, 2020, 07:08:03 AM »
OK thanks. I had not read that about surfaces, and seems to go against the hand washing advice.

Seems opening the widows and getting a bit of welsh wind through the house is the answer for me, after running the O3 gen for an hour.
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rcjordan

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Re: Electrostatic foggers for bulk decontamination
« Reply #17 on: June 23, 2020, 06:58:53 PM »
>Where did you get to with these foggers?

Nothing further, as I didn't like the Ryobi --it simply isn't atomizing enough.  All the electrostatic models seemed to be based on the Victory unit, but prices are around $900.  They are sold out, even if I was going to pay that much.

Rupert

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Re: Electrostatic foggers for bulk decontamination
« Reply #18 on: June 23, 2020, 08:41:05 PM »
One of the Holiday cottage companies we work with said a fogger is recommended by the Govt.  Not sure its great advice.
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ergophobe

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Re: Electrostatic foggers for bulk decontamination
« Reply #19 on: June 24, 2020, 12:48:15 AM »
based on the Victory unit, but prices are around $900.  They are sold out, even if I was going to pay that much.

I see list prices more like $600 ($599), but as you say, they are sold out.

>> surfaces, and seems to go against the hand washing advice.

I don't think the one implies the other. It's all a probability game and there are many things that can infect you from your hands aside from SARS-COV-2.

Most of the infectious disease specialists I have been reading all through the pandemic have been saying roughly what I said above regarding surfaces. It is a theoretical, but difficult, pathway and the main source of infection is breathing exhaled droplets or aerosols from an infected person over an extended period of time (that is, it's almost impossible to get from an infected runner who passes you on a trail, but riding around in the car with an infected passenger and the windows up would not be a good idea).

If you have the mind space to pay attention to everything, then yes, watch those surfaces. But if obsessing on surfaces is decreasing even a bit the mental space you have and therefore your vigilance with respect to aerosols, that's a bad trade in my opinion and that was more Osterholm's point, rather than saying not to wash your hands.

Rather, Osterholm says you should absolutely wash your hands and that personally he does frequently, but he does so mostly because of all the diseases that have always used that pathway effectively. I suspect given his work, back in 2019 he was washing his hands a lot more than average, and he has not really changed practice. But he said specifically, he's not concerned with touching doorknobs, opening mail, bringing groceries into his house. Keep your eye on the airborne pathways.

The Osterholm interview is quite good. I strongly recommend giving it a listen.

That said...
Quote
None of this is to say you should be cavalier when you venture into the outside world. Washing your hands, avoiding touching your face, being diligent about physical distancing, wearing masks in public, and disinfecting communal surfaces all these things likely reduce transmission risk, and we should keep doing them, Rasmussen said.
https://www.vox.com/future-perfect/2020/4/24/21233226/coronavirus-runners-cyclists-airborne-infectious-dose

If you can do only ONE thing, get rid of the aerosols and let everything dry out so the virus casings denature and the virus gets rendered inactive as much as possible. The focus on aerosols and droplets came up over and over and over with the county public health officials.

If you can do seven things, then, sure, disinfect every surface and wear a hazmat suit. I wore a full P100 cartridge mask to go strip the beds because I own two that are right at hand. Stripping beds is going to kick stuff into the air, so why not be safe if it doesn't take much more effort?

Obviously, the level of care you take has a lot to do with your risk tolerance and your objective risk factors. If I were 86 years old with some respiratory issues (my father-in-law), I would be much more careful.

Rupert

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Re: Electrostatic foggers for bulk decontamination
« Reply #20 on: June 24, 2020, 05:44:07 AM »
Quote
get rid of the aerosols and let everything dry out so the virus casings denature and the virus gets rendered inactive as much as possible.

The more I read, the more I think its very fresh in the aerosols. And it does get  less active quite quickly. Not inactive, but less so.

good summary, thanks.

(added: just "listened" instead of "read")
« Last Edit: June 24, 2020, 06:45:21 AM by Rupert »
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ergophobe

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Re: Electrostatic foggers for bulk decontamination
« Reply #21 on: June 24, 2020, 06:51:49 PM »
I think of it as a sliding scale of probabilities. By way of analogy, though in no way implying actual mathematical equivalence since I do not the actual numbers

Level 1
 - hanging out indoors in a large group of strangers with the windows shut and everyone singing in a town where the hospitals are overwhelmed and out of ventilators
 - driving drunk at night on a curvy mountain road

Level 2
 - Physical distancing, washing your hands regularly, wearing a mask when you get groceries
 - Driving the speed limit and obeying all laws, well-rested

Level 3
 - Effectively in quarantine, disinfecting everything that comes into the house, not touching anything from outside for 72 hours, disinfecting every surface that might have been touched by someone else.
 - driving only during the day, 10-15mph below the speed limit, in the safest car on the market with all the driver-assist and a co-pilot passenger to help you watch the road.

For someone who is high risk for Covid or for my elderly in-laws with very bad night vision, Level 3 is perhaps the right level.

But most people accept various forms of risk. As a result of abolishing the 55mph speed limit in the US, we accept an additional 5,000 deaths per year on the roads. People have decided that being able to get somewhere a few minutes faster is worth 5,000 deaths per year. Nobody I know regularly drives well below the current speed limits, because they think the reward/risk is not high enough. But everyone I know has a slightly different tolerance for risk while driving.

https://www.consumerreports.org/car-safety/higher-speed-limits-led-to-36760-more-deaths-study-shows/

I see Covid like that. Some people throw down three beers and speed home. Most people only drive sober, but typically got a few miles per hour over the speed limit in the US.*


*I was surprised 20 years ago when I spent two months in Australia and drove 15,000km and found that, especially in Queensland, people regularly drove below the speed limit and rarely over. But that's because the OZ speeding enforcement is fairly raitional and in the US it is completely arbitrary and ridiculous.
« Last Edit: June 24, 2020, 06:55:39 PM by ergophobe »