COVID-19 disinfectant in microscopy core question

[Cammer, Michael-2]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
Post images on http://www.imgur.com and include the link in your posting.
*****

This is a question for the people interested in microscope room decontamination.  We are being told to be ready for reopening labs and a question has arisen whether 70% EtOH is really best for wash downs.


A colleague working is getting deep into lit review of disinfection methods.


He says that the lit argues for spiking alcohol with a small amount of hydroxide &/or SDS.  SPecifically, a formulation such as 30% ethanol, 1.5% propanol is effective and it strong enough to even denature prions with additions of “accelerants” of 0.2 % SDS (a.k.a. sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS)) and 0.3 % NaOH (or similar KOH).
This is consisent with Purel.

Would this be of benefit in a microscopy lab?
What about the SDS or Na/KOH on instruments?  (obviously not the optics)

This the the gist of the question.  Pasting in a longer draft document below (my editing, not authorship) if interested in more details.  If you read the document below, it ends with a discussion of alcohol concentrations.

What are alcohol concentrations you recommend?  These docs suggest 70% more than 2X necessary, especially if other "accelerants" included in formulations.

Cheers-
Michael


We have to make judgments regarding disinfection in an area where authorities do not have empirical data or rely on reviews that maybe incorrect.  For instance, Kampf et al 2020 https://www.journalofhospitalinfection.com/article/S0195-6701(20)30046-3/fulltext has at least one spurious piece of data regarding hydroxide, saying that it is effective when likely useless, and the authors and journal editor have been unresponsive to calls for various parties to clarify.
Other publications are more thorough and based in empirical testing.  Simple alcohol is great, but additions of surfactants or hydroxides in very small amounts may greatly increase potency and at least one popular commercial product line, the Purell surface cleaners (same formulation marketed for multiple uses).  The accelerants help the dilute solvent get past capsids, lipid layers, dissolve endospores, prions, etc.

The take home message is that a formulation such as 30% ethanol, 1.5% propanol is effective and it strong enough to even denature prions with additions of “accelerants” of 0.2 % SDS (a.k.a. sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS)) and 0.3 % NaOH (or similar KOH).

A crucial advantage of this approach is that, because of their low concentrations, the disinfectants are much less toxic, much less dangerous, and, in most cases, less harmful to most sensitive materials. The claimed safety of these formulations is extraordinary --  disinfectants with dwell times as low as thirty seconds for satisfactory kill of a wide range of tough pathogens. Before their introduction, if people wanted anything even remotely as efficacious in a disinfectant, they had to expose themselves to serious respiratory, dermal, oral, and ocular risks.  These are improvements.

This first memo deals only with the first approach, which centers around activating very dilute alcohol in order to create a potent but minimal risk disinfectant with a Class IV (lowest) toxicology risk rating .

(Approach #2, activating very dilute hydrogen peroxide, covered in another memo.)

Approach #1: Spike a dilute (20% to 50%) alcohol solution with a bit of surfactant (SDS is used in the published DIY formula for scientists' use; undisclosed in the Purell formula alternatives may have been mentioned in the patent application) and lye (potassium hydroxide is used in Purell's formula and listed in safety data sheets; sodium hydroxide is used in the published DIY formula).

The experimentally validated DIY formula is described in detail here:

Beekes, M., Lemmer, K., Thomzig, A., Joncic, M., Tintelnot, K., & Mielke, M. (2010). Fast, broad-range disinfection of bacteria, fungi, viruses and prions. The Journal of General Virology, 91(Pt 2), 580–589.

In brief, it denatures prions with this formulation, so likely to kill viruses:  “A mixture of 0.2 % SDS and 0.3 % NaOH in 20 % n-propanol achieved potent decontamination of steel carriers contaminated with PrP(TSE), the biochemical marker for prion infectivity, from 263K scrapie hamsters or from patients with sporadic or variant Creutzfeldt-Jakob disease.”

The patented version marketed by Purell is described in peer-reviewed articles here:

Alhmidi, H., Koganti, S., Cadnum, J. L., Rai, H., Jencson, A. L., & Donskey, C. J. (2017). Evaluation of a Novel Alcohol-Based Surface Disinfectant for Disinfection of Hard and Soft Surfaces in Healthcare Facilities. Open Forum Infectious Diseases, 4(2), ofx054.

Edmonds, S. L., Macinga, D. R., Mays-Suko, P., Duley, C., Rutter, J., Jarvis, W. R., & Arbogast, J. W. (2012). Comparative efficacy of commercially available alcohol-based hand rubs and World Health Organization-recommended hand rubs: formulation matters. American Journal of Infection Control, 40(6), 521–525.

And in promotional copy on Purell's website here:

         https://www.gojo.com/en/Markets/Acute-Care/PURELL-Surface?sc_lang=en

Based on page 12 of a recent version of the Safety Data Sheet, found here, the amount of lye (0.35%) and alcohol (20-30%) is revealed:
         https://www.officedepot.com/pdf/msds/354245.pdf
and these are the actual formulation and reported range of effective formulation if recipe changed ad hoc:
Water (Aqua)

7732-18-5

balance%

Ethyl Alcohol

64-17-5

29.4 %

Isopropyl Alcohol

67-63-0

1.42 %

Potassium Hydroxide

1310-58-3

0.35 %







Effective range:
Water (Aqua)

7732-18-5

70 - 90 %

Ethyl Alcohol

64-17-5

20 - 30 %

Isopropyl Alcohol

67-63-0

1 - 5 %

Potassium Hydroxide

1310-58-3

0.1 - 1 %



It's possible that one or more other 'trade secret'  is included in Purell's formulation and is actually necessary to its efficacy, but I doubt it because of how closely Beekes et al's observed efficacy resembles Gojo's claimed efficacy. And Beekes et al only used the aforementioned 3 ingredients.

Also note that Purell might have used up to 50% more total alcohol than in Beekes et al, and uses two types of alcohol... but the excess may be for consumer acceptability; more alcohol provides more solvent for grease-cutting, and could provide a preferred faster dry time for wiping counters down without drying. Indeed, Purell markets it as a surface disinfectant and surface cleaner.

Purell's formula leaves a slight white chalky residue on surfaces as it dries, but the powder is extremely insubstantial (think: hard water spots on a glass), and it's extremely easy to rinse it off because it's extremely water soluble, completely non-oily, non-tacky.






Michael Cammer, Sr Research Scientist, DART Microscopy Laboratory

NYU Langone Health, 540 First Avenue, SK2 Microscopy Suite, New York, NY  10016

[hidden email]<mailto:[hidden email]>  http://nyulmc.org/micros  http://microscopynotes.com/

Voice direct only, no text or messages:  1-914-309-3270 and 1-646-501-0567

[Roland Nitschke]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
Post images on http://www.imgur.com and include the link in your posting.
*****

To remember for disinfection we also have to take care, if you do it on
microscope parts,  not to damage the microscope. Therefore, I wrote to
all microscope companies beginning of April to send or publish
information about it. Quick summary: use 70% alcohol should be save for
all microscopes, avoid aerosol building and to much fluid.

Here find the result/repsonse from the big four plus Okolab.

Collection of websites about microscope and microscope incubator
disinfection:

Leica

https://www.leica-microsystems.com/science-lab/how-to-sanitize-a-microscope

Nikon

https://www.microscope.healthcare.nikon.com/about/news/recommended-handling-and-disinfecting-procedures-for-nikon-microscope-products-to-reduce-spread-of-infectious-agents-including-sars-cov-2-coronavirus

Okolab

http://oko-lab.com/covid-19-update/cleaning-recommendations-for-okolab-products

Olympus

https://www.olympus-lifescience.com/en/discovery/how-to-clean-and-sterilize-your-microscope

Zeiss

https://www.zeiss.com/microscopy/int/solutions/laboratory-routine/clinical-laboratory/virology.html


We also have put together all informations available for download here
(links in the upper right corner):

https://www.miap.eu/

All information,  plus much more related to the topic of running a
facility in Corona days will be coming soon in paper by a joint effort
from GermanBioImaging.

Also look here: https://www.gerbi-gmb.de/Corona

Best

Roland

Dr. Roland Nitschke Albert-Ludwigs University Freiburg Life Imaging
Center (LIC) in ZBSA Microscopy and Image Analysis Platform (MIAP)
Habsburgerstr.49 79104 Freiburg Germany e-mail:
[hidden email] <mailto:[hidden email]>
phone: [phone] fax: [phone] web LIC:
https://miap.eu/miap-units/life-imaging-center-lic/ web MIAP:
https://miap.eu <https://miap.eu/>


Am 29.04.2020 um 15:33 schrieb Cammer, Michael:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> Post images on http://www.imgur.com and include the link in your posting.
> *****
>
> This is a question for the people interested in microscope room decontamination.  We are being told to be ready for reopening labs and a question has arisen whether 70% EtOH is really best for wash downs.
>
>
> A colleague working is getting deep into lit review of disinfection methods.
>
>
> He says that the lit argues for spiking alcohol with a small amount of hydroxide &/or SDS.  SPecifically, a formulation such as 30% ethanol, 1.5% propanol is effective and it strong enough to even denature prions with additions of “accelerants” of 0.2 % SDS (a.k.a. sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS)) and 0.3 % NaOH (or similar KOH).
> This is consisent with Purel.
>
> Would this be of benefit in a microscopy lab?
> What about the SDS or Na/KOH on instruments?  (obviously not the optics)
>
> This the the gist of the question.  Pasting in a longer draft document below (my editing, not authorship) if interested in more details.  If you read the document below, it ends with a discussion of alcohol concentrations.
>
> What are alcohol concentrations you recommend?  These docs suggest 70% more than 2X necessary, especially if other "accelerants" included in formulations.
>
> Cheers-
> Michael
>
>
> We have to make judgments regarding disinfection in an area where authorities do not have empirical data or rely on reviews that maybe incorrect.  For instance, Kampf et al 2020 https://www.journalofhospitalinfection.com/article/S0195-6701(20)30046-3/fulltext has at least one spurious piece of data regarding hydroxide, saying that it is effective when likely useless, and the authors and journal editor have been unresponsive to calls for various parties to clarify.
> Other publications are more thorough and based in empirical testing.  Simple alcohol is great, but additions of surfactants or hydroxides in very small amounts may greatly increase potency and at least one popular commercial product line, the Purell surface cleaners (same formulation marketed for multiple uses).  The accelerants help the dilute solvent get past capsids, lipid layers, dissolve endospores, prions, etc.
>
> The take home message is that a formulation such as 30% ethanol, 1.5% propanol is effective and it strong enough to even denature prions with additions of “accelerants” of 0.2 % SDS (a.k.a. sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS)) and 0.3 % NaOH (or similar KOH).
>
> A crucial advantage of this approach is that, because of their low concentrations, the disinfectants are much less toxic, much less dangerous, and, in most cases, less harmful to most sensitive materials. The claimed safety of these formulations is extraordinary --  disinfectants with dwell times as low as thirty seconds for satisfactory kill of a wide range of tough pathogens. Before their introduction, if people wanted anything even remotely as efficacious in a disinfectant, they had to expose themselves to serious respiratory, dermal, oral, and ocular risks.  These are improvements.
>
> This first memo deals only with the first approach, which centers around activating very dilute alcohol in order to create a potent but minimal risk disinfectant with a Class IV (lowest) toxicology risk rating .
>
> (Approach #2, activating very dilute hydrogen peroxide, covered in another memo.)
>
> Approach #1: Spike a dilute (20% to 50%) alcohol solution with a bit of surfactant (SDS is used in the published DIY formula for scientists' use; undisclosed in the Purell formula alternatives may have been mentioned in the patent application) and lye (potassium hydroxide is used in Purell's formula and listed in safety data sheets; sodium hydroxide is used in the published DIY formula).
>
> The experimentally validated DIY formula is described in detail here:
>
> Beekes, M., Lemmer, K., Thomzig, A., Joncic, M., Tintelnot, K., & Mielke, M. (2010). Fast, broad-range disinfection of bacteria, fungi, viruses and prions. The Journal of General Virology, 91(Pt 2), 580–589.
>
> In brief, it denatures prions with this formulation, so likely to kill viruses:  “A mixture of 0.2 % SDS and 0.3 % NaOH in 20 % n-propanol achieved potent decontamination of steel carriers contaminated with PrP(TSE), the biochemical marker for prion infectivity, from 263K scrapie hamsters or from patients with sporadic or variant Creutzfeldt-Jakob disease.”
>
> The patented version marketed by Purell is described in peer-reviewed articles here:
>
> Alhmidi, H., Koganti, S., Cadnum, J. L., Rai, H., Jencson, A. L., & Donskey, C. J. (2017). Evaluation of a Novel Alcohol-Based Surface Disinfectant for Disinfection of Hard and Soft Surfaces in Healthcare Facilities. Open Forum Infectious Diseases, 4(2), ofx054.
>
> Edmonds, S. L., Macinga, D. R., Mays-Suko, P., Duley, C., Rutter, J., Jarvis, W. R., & Arbogast, J. W. (2012). Comparative efficacy of commercially available alcohol-based hand rubs and World Health Organization-recommended hand rubs: formulation matters. American Journal of Infection Control, 40(6), 521–525.
>
> And in promotional copy on Purell's website here:
>
>           https://www.gojo.com/en/Markets/Acute-Care/PURELL-Surface?sc_lang=en
>
> Based on page 12 of a recent version of the Safety Data Sheet, found here, the amount of lye (0.35%) and alcohol (20-30%) is revealed:
>           https://www.officedepot.com/pdf/msds/354245.pdf
> and these are the actual formulation and reported range of effective formulation if recipe changed ad hoc:
> Water (Aqua)
>
> 7732-18-5
>
> balance%
>
> Ethyl Alcohol
>
> 64-17-5
>
> 29.4 %
>
> Isopropyl Alcohol
>
> 67-63-0
>
> 1.42 %
>
> Potassium Hydroxide
>
> 1310-58-3
>
> 0.35 %
>
>
>
>
>
>
>
> Effective range:
> Water (Aqua)
>
> 7732-18-5
>
> 70 - 90 %
>
> Ethyl Alcohol
>
> 64-17-5
>
> 20 - 30 %
>
> Isopropyl Alcohol
>
> 67-63-0
>
> 1 - 5 %
>
> Potassium Hydroxide
>
> 1310-58-3
>
> 0.1 - 1 %
>
>
>
> It's possible that one or more other 'trade secret'  is included in Purell's formulation and is actually necessary to its efficacy, but I doubt it because of how closely Beekes et al's observed efficacy resembles Gojo's claimed efficacy. And Beekes et al only used the aforementioned 3 ingredients.
>
> Also note that Purell might have used up to 50% more total alcohol than in Beekes et al, and uses two types of alcohol... but the excess may be for consumer acceptability; more alcohol provides more solvent for grease-cutting, and could provide a preferred faster dry time for wiping counters down without drying. Indeed, Purell markets it as a surface disinfectant and surface cleaner.
>
> Purell's formula leaves a slight white chalky residue on surfaces as it dries, but the powder is extremely insubstantial (think: hard water spots on a glass), and it's extremely easy to rinse it off because it's extremely water soluble, completely non-oily, non-tacky.
>
>
>
>
>
>
> Michael Cammer, Sr Research Scientist, DART Microscopy Laboratory
>
> NYU Langone Health, 540 First Avenue, SK2 Microscopy Suite, New York, NY  10016
>
> [hidden email]<mailto:[hidden email]>  http://nyulmc.org/micros  http://microscopynotes.com/
>
> Voice direct only, no text or messages:  1-914-309-3270 and 1-646-501-0567

[Martin Spitaler-2]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
Post images on http://www.imgur.com and include the link in your posting.
*****

Dear Michael,

   you have pretty much already answered your own question: "The accelerants help the dilute solvent get past capsids, lipid layers, dissolve endospores, prions, etc."

  As Sars-CoV2 obviously doesn't contain endospores, prions etc., the only thing you need to achieve to deactivate the virus is to dissolve the lipid layer. That's the simple explanation why 70% EtOH (or another alcohol) is perfectly fine, and why soap is just as good or even better (but obviously we can't use it on microscopes).

  For an excellent overview from a nanoparticle chemist's perspective see Palli Thordarson's wonderful blog "Why does soap work so well on the SARS-CoV-2, the coronavirus and indeed most viruses? " (https://threadreaderapp.com/thread/1236549305189597189.html).

Best wishes,

Martin

________________________________________
Martin Spitaler, PhD
Head of the
Imaging Facility
Max Planck Institute of Biochemistry
Am Klopferspitz 18
82152 Martinsried
Germany
Tel: [phone]
E-mail: [hidden email]
Website: http://www.biochem.mpg.de/en/facilities/imaging