Final word on NOT using alcohol on tools

[Cynthia, Prescott, AZ]

I emailed Aaron Hicks, author of 'Asymbiotic Technique of Orchid Seed Germination', and who runs the Orchid Seedbank Project in Chandler, Arizona, about using alcohol for tool sterilization, as some one was insisting was OK here. In the past I have found him very knowledgeable about orchid viruses. Here is his reply:

"They're flat-out wrong. Alcohol does not denature tobamoviruses. All it does is preserve the virus long enough to infect the cutting tool, and pass it along. This is documented in Disinfection, Sterilization, and Preservation by Seymour Block, IIRC. We had a nitwit doctoral student who would dip her tools in the same ethanol quench used to cool tools after sitting in the bead box. Dip, heat, dip, and back to work."

I assume the 'bead box" is a device for heating tools for sterilization. So, let us all please find some other method of sterilizing our tools other than alcohol. Cynthia

[Willc73]

I did a search at ars.usda.gov and the cdc.
The usda states using 91% alcohol to disinfect for tobamoviruses works.
Also the CDC uses Alcohol to disinfect against all viruses.
Perhaps the common 70% alcohol is insufficient, however I believe higher levels of alcohol should work well.

[mayres]

I'm wondering if it is really possible to EVER come to that place of finding the "FINAL" word? I don't pretend to be an expert on this subject and it certainly is confusing reading conflicting opinions on this and other forums and sites. Doing a little exploring on the internet I find orchid societies, scientiests, etc. recommending everything including the use of alcohol, TSP, 5% chlorox, heat 400 for 2 hours, propane torch flame for 5-7 seconds, 2 seconds with 1 part household bleach plus 1 part water, followed by a rinse of 1 part vinegar with 5 parts water and 1 tsp. salad oil. It seems that everyone has each method on the word of the highest authority - hmmm.

[Cynthia, Prescott, AZ]

Can you give me the site address where this statement is made. You seem to be better at finding this than I am. Cynthia

[mayres]

Cynthia - I didn't write them all down, but I do remember that the propane flame sterilization method is recorded in the Ortho book on Orchids. Believe it or not the alcohol method is suggested by the Ontario Orchid Society on their web page. The other suggestions were all listed on another person's orchid page. The more I looked the more it seemed that there is no concensus. I didn't list any of these in order to prolong an argument - just pointing out that for those trying to come to a conclusion on how to proceed it is difficult to come to a "final" conclusion. Fortunately my humble little collection is small enough that I can merely make my divisions and do my pruning using my fingers - no tools needed. (Put a pair of sterile disposable gloves on before each activity?). Anyway - thank you for all your comments and the hours and hours you spend giving EXCELLENT advice. mike

[Willc73]

There is a big difference between Sterilizing and Disinfecting.
A tool made out of steel can easily be disinfected with alcohol, or soap and water. To sterilize bark or potting material, thats a whole other story.

[orchidsinjersey]

Since I had posted on the use of alcohol for disinfecting, (note that I did not say sterlizing; if you don't know the difference, you need to), I'll post again. Tobaviruses are inactivated in alcohol. Flaming in alcohol is the standard technique microbiologists use for sterilizing metal tools. 10% bleach disinfects but does not sterilize. Same thing for the quats, phenols, etc. Autoclaves sterilize, so do germicidal lamps (but you have to know how to use them). Once the coat proteins of the viruses have been "fixed" in alcohol (or glutaraldehyde), the infectious capacity of the virus (that is, the ability to inject its RNA to take over the cell) has been reduced by several orders of magnitude.
Virologists I posed this question to agree with me.

[Cynthia, Prescott, AZ]

My request for the site address was direcrted to Willc73. Sorry for the confusion, Cynthia

[Anton]

Well in the past I have used soap and water to "clean" my tools first and 1:1 bleach to disinfect afterwards and haven't had a problem as yet.

I work in an Ophthalmology unit in a major teaching hospital and we are no longer allowed to clean out optical instruments with alcohol as has been stated before it sets the viruses but not kill them.

In Ophthalmology we have to be exceptionally careful with disinfecting as any laxety on our behalf could spread a disease from one person to another thereby causing blindness. Don't orchids deserve the same care ??

We now have to use a moist towelette which has a mild soapy solution to clean chin rests, tables instruments etc., this wipes of the "bugs", and THEN wipe over with alcohol swabs. Maybe the same should follow for orchids.

If needed I can get the infection control RN to send me the full details on what to use and why as he is a personal friend of mine.

[Cynthia, Prescott, AZ]

The info from your RN might be interesting. From reports of alcohol maintaining the virus, use of alcohol to follow other methods should involve fresh alcohol with each tool. Sounds like one good method should be enough. Cynthia

[Anton]

The wipes we now use are called "Tuffie Wipes" and I think should be available in he States.

The detergent in them actually kills off the "bug's" protein thereby rendering almost useless as they are easily wiped off. If you use alcohol the protein actually sticks to the surface that is being wiped allowing it to still do it's dirty little deeds.

http://www.vernacare.com/tuffie_wipes.html