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Fogging the Air

I wrote a post a while back on what I saw as “decontamination theater”: the shots (originally from China) of people fogging buildings and outdoor scenes with what was often described as some sort of disinfectant. As I wrote at the time, I was unaware of any antiviral sanitizing agent that was dispersed in this way.

Well, I stand corrected, up to a point. There is a literature on the use of triethylene glycol (TEG) vapors as an air sanitizer, and that is a common ingredient in commercial “fog machine” devices. A lot of the literature on this technique goes back to the 1940s and 1950s and mostly studied its antibacterial action, but as you can see from those first two links in this paragraph, it can also inactivate influenza viruses and a series of bacteriophages (which were used as models for other pathogens). I can find no references specific to coronaviruses, but one could imagine that their lipid-envelope nature would make certainly make them vulnerable as well.

I hope that’s correct, though, because as you can see from that second link, there was at least one bacteriophage whose infectiousness increased after the vapor treatment. Unnervingly, that was the phi6 bacteriophage, which has a lipid envelope as well (a relatively rare trait in phages), so that makes a person wonder what the effect is on the coronaviruses as a whole. That same paper also found that TEG was overall less effective than hydrogen peroxide mist, eugenol (from oil of cloves) vapors or Pledge-brand disinfectant spray (which contains benzylammonium chlorides found in many other such products). So this whole thing is not as straightforward as it seems.

To emphasize that, here’s the EPA’s page on glycol air sanitizer products. This part in particular struck me:

Adequate experimental data is available to show that air sanitizers do not sterilize, disinfect, act as a germicide, or protect experimental animals from infections by airborne bacteria or viruses. Thus, claims of value in preventing or treating diseases, or providing any other health protection, whether expressed or implied, are not acceptable.

So I’m back to wondering if these fogging devices are doing any good, especially when deployed in the open air. There’s more rationale to them than I had thought, but is there any evidence that they’re actually doing anything? Or not perhaps even making things worse?






26 comments on “Fogging the Air”

  1. JasonP says:

    The link to TEG takes you to wiki page where it notes Oust as a containing product. A quick search on eBay for those products shows several available – at outrageous prices.

    Looks like some ‘enterprising’ individual in Racine, WI is likely raiding the employee/company store and offering a 10oz can of Oust for $28 – free shipping included!

    I guess eBay allows this kind of price gouging? Wonder why the company allows its employee store to be used this way?

    Now where is that Clove Oil I stock piled to ward off ALZ and perioxynitrates? Would this qualify as re-purposing a curative?


    1. doc says:

      The company does not allow that. It is explicitly prohibited. From personal knowledge and experience, I can also say that few (if any) company employees are so venal. The presumption that it’s a company employee is just that- an unsubstantiated presumption.

  2. Lane Simonian says:

    Here is a somewhat curious Federal Aviation Administration report on the use of hydrogen peroxide and triethylene glycol as disinfectants on airplace surfaces.

    Of course, I would not be so dismissive of the anti-viral potential of eugenol. (the Laurus nobilis berries referenced in this article contain eugenol).

    Currently (to the best of my knowledge) Vitamin C infusions are the only natural product in clinical trial for the potential treatment of the coronavirus.

    Ginseng is another long shot:

    1. Lane Simonian says:

      I provide a duplicate link again. Here is the correct one for Laurus nobilis.

    2. SnupSnus says:

      Lane zinc is also a “natural product” (I guess that depends on the definition of “natural product”), and it was used for HK-SARS, seasonal Corona Virus and is part of the Wuhan-SARSV protocoll in some places. Some recommend supplementing zinc, what do in the pipeline readers think about that? I’ll send some papers from PC later

      1. JasonP says:

        This Pipeline reader defaults to a bit of education from MedCram on Youtube, Coronavirus Epidemic Updates 32 & 34.

        Problem is getting enough Zn into the cell.

      2. JasonP says:

        This Pipeline reader defaults to a bit of education from MedCram on Youtube, Coronavirus Epidemic Updates 32 & 34. Good detailed explanation, well worth the educational time invested.

        Problem is getting enough Zn into the cell.

        1. JasonP says:



    3. Alderman says:

      TEG + peroxynitrite spray FTW

  3. Nick lee says:

    Fog machines, strobe lights, and pounding EDM in every public indoor place! Coronavirus HATES rave parties!

    1. Pyro says:

      Or potentially, given that TEG fogging *increased* the virulence of a phage with a lipid envelope like SARS-CoV-2 has, loves raves.

      Also the whole “extensive bodily contact” thing…

  4. A Nonny Mouse says:

    Propylene glycol is also used for fogging machines (this is why it is used in nicotine vapes). Maybe this is better?

    As for price gouging, my daughter is trying to get back to the UK from DC where she has been studying. She managed to get a flight for Wednesday with BA for $480 (+$300 for bags!). That same economy fare is now $2,700.

  5. MagickChicken says:

    Eugenol from oil of cloves. Oh good, that’s not going to encourage the oils/crystal healing whackos at all. . .

  6. kevin says:

    Maybe it’s too early to tell, but what’s this year’s job market going to look like? Would it be close to the post mortgage crisis level?

  7. BernYeeViruses says:

    The literature on coronavirus virucides is not as extensive as one might have hoped- but the WHO published this in 2017- Virucidal Activity of World Health Organization–Recommended Formulations Against Enveloped Viruses, Including Zika, Ebola, and Emerging Coronaviruses

    Google this and see that hydrophobic alcohols are better- following basic rules of lipophilicity and membrane perturbation.

    Be safe out there!

  8. Daniel Barkalow says:

    Interesting to see something in clove oil on the list; I’ve been using clove hard candies to treat sore throats for years. I’ve assumed that they have no effect on any causative agents, but they definitely make me less miserable (in terms of pain and irritation; my throat feels numb after one), which isn’t bad for something sold by the pound at the candy shop. It’d be amusing if I was incidentally disinfecting my coughs.

  9. wallyc says:

    Derek, here’s a disinfectant that might be in use, but not specific to fogging:
    General introductory info
    See the patents and list of licensees in below:
    In the news, one licensee “plans to ship” (unknown if this actually happened) 560,000 pounds of Decon7 go to China…

  10. Suncreen says:

    Well, but there is obviously some advantage to disinfectant in the air, its called UV radiation. However, UV can’t be injected into a person by an oxford trained smart dude, so that’s not gonna get a lot of traction is it????

  11. charlesj says:

    Another approach is the fuel-air bomb, featured in the movie ‘Outbreak’

  12. WildCation says:

    Eugenol – get all those chemistry undergraduates working to extract it! They already have the procedure in their lab manuals. There aren’t any possible downsides to getting undergraduates back into crowded university labs, and the product is definitely going to be pure enough to be safe to use. My plan is flawless! Flawless, I say!

    1. in indonesia, eugenol can be used to care toothache too

  13. bacillus says:

    I’ve used Decon 7 to fog an ABSL3 lab before. Their website claims it is effective against SARS and it killed all of the strips of Bacillus spores I hung up to test for efficacy. Tried it twice instead of sublimation of paraformaldehyde, before reverting to the latter as it is difficult to spend two hours in a negative pressure full face rerspirator whilst walking around a 10,000 cubic foot lab with a 2 gallon fogger trying to get into every nook and cranny. It takes ages before you can peel your scrubs off, and you lose a few pounds in the process. Far better to throw 2.5 kg of paraformaldehyde into several electric fry pans, seal up the doors and walk away until the following morning .

  14. FOGCLEAN says:

    Validation is key to fogging!

    Very few operators are able validate any kind of log reduction.

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