washing textiles in 70% ethanol and 30% water solution?

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    • #132546
      Charlene Martin

      I’ve read on this board about dabbing this solution on the area of mold growth, but can I hand-wash the entire textile artifact in this? The items are not fragile or old.

      Thank you for your help with this!


    • #132554
      Ann Frisina

      I think it really depends on how large the textile is and how much ethanol.  Do you have a way to get rid of the ethanol fumes?  I recently worked bathing a smaller textile and had a reaction to the ethanol even with fume extraction.




    • #132553
      Charlene Martin

      Hi Ann-

      Good point, I tend to think more about the artifact, less about me 🙂 Since it’s summer, I will hand wash the textile in a bucket outdoors.


    • #132552

      Whoa, this is scary stuff! Let’s check where this recommendation is coming from because I’m pretty certain someone has their percentages mixed up, with some scary consequences!!!

      Ethanol is a) extremely flammable, b) a serious intoxicant and c) a strongly hygroscopic.  What does all this mean?

      First, 70% ethanol is A LOT of ethanol. Generally, when conservators use ethanol we use tiny amounts – fractions of 1% – to take advantage of the lower surface tension and to increase wetting of water-based solutions.

      Hygroscopicity: At 70% ethanol will literally “suck” all the water out of any textile fiber causing extreme shrinkage, dessication that could be permanent.  Almost all fibers have a latent “water of constitution” – water that is chemically attached to the fiber and fundamental to fiber properties such as strength, flexibility, drape and color.  Loose that water by leaching it out with ethanol and there is no getting that water back into the fiber! Also, this reaction is exothermic – that is that heat is given off at the fiber as the water of constitution is lost.  In the case of protein fibers, the temperature at the fiber level can exceed the temperature of shrinkage of the protein and the whole thing can collapse into gelatin!

      70% ethanol is 140 proof alcohol. Inhaled, it will have you flat on your back in minutes and probably pretty nauseous, along with some upper respiratory damage.  Secondly, it is a serious solvent for fats – This much ethanol will not only dissolve and extract the fats from your skin, it will do the same for your liver, eyes, etc.  There are some NASTY health implications here!

      ANY source of ignition – a static spark from your clothing, an on-off switch on the wall, a cell phone, a electric motor in a printer or computer, a water heater, an air conditioner – can ignite 70% ethanol into a MASSIVE ball of fire.

      Does anyone know where this recommendation is written in the literature? Let’s get the numbers right!

      Remember that at relative humidity below 62%, all conidia and spores (sexual and asexual “seeds” of mold) are inactive and the mold hyphae is dead. You do not have to KILL mold, you only have to dry it in conditions less than 60% Relative humidity.  The pigmented staining caused by stressed mold is another story, altogether. But alcohol is NOT needed to kill mold.  Mold conidia are ubiquitous in the air so there is no way to avoid it other than lower the RH.


    • #132551
      Charlene Martin

      Thank you Dale for this extra information. The 70/30 ratio was included in a 2012 post on this board about mold on a corn husk doll, but I didn’t seek additional authoritative sources.


      I was reviewing the Tara Kennedy webinar from Feb. re: mold when I noticed your post. She addressed lowering the temp. to freezing to kill active mold, but added that air-drying can reactivate it.  Dale, I am able to maintain 30% RH in my collection – so according to what you mentioned, the spores (not the mold) would be dead and in a dried state that will facilitate the mold and spore removal? Tara recommended a HEPA vacuum to remove the dried mold/spores, is that all that is needed? Are there recommended HEPA vacuum/filter brands/models, or can I be cost-effective when I shop?


      Thank you to everyone who joins this discussion, I am learning a lot!


    • #132550

      On the flowering and vegetative, branched portions of mold, there are huge numbers of conidia so using a HEPA vac nozzle covered with nylon window screen as a “pick-up” above the textile while you gently brush the mold plant materials off the textile with a soft brush is an excellent idea.  But be careful not to do this “cleaning” activity in collections rooms or offices.  Weara fine particle mask and clothing or a smock that you can remove and launder separately after your work is done. Otherwise you’ll be walking around with extra conidia up your nose all day long!

      Mold conidia are allergens and in large numbers can make people ill, so pulling them away into an airstream created by a HEPA vac and trapping them is a good idea.  Just remember that all those spores and conidia now live in the HEPA filter in huge numbers so change the filter outdoors, in good ventilation, standing “up-stream” and wear a fine particle mask and washable clothing.

      Cleaning your worktable, tools, vacuum nozzle and work area is strongly advised too, because the conidia will have been shed in large numbers during the cleaning process. Surfactant (dish washing detergent) and water (like washing dishes in the sink) is very effective but to truly disinfect, using rubbing alcohol 70% isopropyl and water just as you buy it from the drug store.  Hmmm, I wonder if THIS is the original source of the misunderstanding?) This is also an excellent degreaser so wear nitrile gloves that you can then wash or dispose of.


      At 30% RH all the mold in your collections are passive rather than alive. For diminishing staining, really get a textile conservator involved.  Good luck and post other questions!

    • #132549
      Charlene Martin

      Whoops, reversed some data: at 30% RH, the mold is dead, the spores are not. So the question remains: can a HEPA filter/vacuum be used to remove the dried mold and spores?

      Thank you!




    • #132548

      70/30 ethanol/water is the standard treatment for mold. If a textile is moldy,the mold will be killed by a quick wetting – spraying is often the easiest way to apply small amounts where needed and limit the amount of alcohol used. Vacuuming first with a HEPA-filtered vacuum cleaner is helpful if there’s a lot of mold. There is no justification for using that solution for washing. No amount of alcohol, however, will prevent mold growth if the piece is put back in the environment that encouraged the mold growth in the first place.

    • #132547

      Barbara – Didn’t Mary-Lou Florian’s extensive research on mold show that isopropyl was more effective at killing conidia – making them non-viable -than ethanol? If the mold is in a passive state, there is nothing to “kill”.  Does the literature someplace suggest spraying things as a matter of course? What’s the point?

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