DIY Hand Sanitizer

  • Admin

    Quick and Easy

    • Ethanol (96%)
    • Aloe vera gel
    • Tea tree oil

    Mix 3 parts isopropyl alcohol to 1 part aloe vera gel. Add a few drops of tea tree oil for the smell.


    • Ethanol (96%)
    • Glycerol
    • Hydrogen peroxide
    • Distilled water

    Less sticky than the previous recepie and the recommended mixture by the WHO.

    Mix 2.5 dL ethanol with 30 millilitre of glycerol (keeps the alcohol from drying out your hands).
    Mix in 15 millilitre of hydrogen then another 60 millilitre of distilled or boiled (then cooled) water.

    These proportions will give you a spray that can be applied to hand towels for wiping of hands and surfaces. Use less water if you want a more gel-like substance.

  • Hero Member

    Anyone know for how long the Coronavirus can survive on a surface and still pose a threat? For example, if someone with Cornavirus at a factory in China coughs all over a new multimeter,
    alt text
    which is then shipped to you in your country, when is it safe to touch it without first disinfecting it?

    The same question for electronic or any other parts. Anyone know? My wife thinks that heat is enough to kill it, which may be a solution for electronic parts that you reflow. I don't like the idea of baking a sensitive multimeter or other sensitive equipment though.

    It seems that the question was only just very recently answered by actual science. As reported by Wired and others, it can survive on plastic or metal for up to 3 days. If that's the upper limit (?), then by the time you receive it I guess it should be safe. Previous predictions were that it could last up to 9 days on surfaces:

  • @NeverDie Recall reading it can survive only 4-5 hours so you should be safe enough from origin...
    A misting with chlorus or alcohol is recommended for work surfaces etc, so a spray and wipe down would erase any possible re-infection.
    Electronics are less likely to be damaged by alcohol mist, >=60%

  • Hero Member

    @zboblamont said in DIY Hand Sanitizer:

    A misting with chlorus or alcohol is recommended for work surfaces etc, so a spray and wipe down would erase any possible re-infection.

    By "chlorus", do you mean chlorous acid? I'm interested to learn what people are using. Here we're using peracetic acid as a high level disinfectant, but it's hard to acquire even without a pandemic, and with the pandemic supplies have dried up.

    alt text

  • @NeverDie Hilarious cartoon but so apt, the UK suffers from a similar idiot...
    By chlorus I meant sodium hypochlorite solution, essentially dilute bleach. Fine for worktops or plastics but reacts with metals etc. hence alcohol less aggressive and quickly evaporates.

  • @NeverDie I heard that on smooth surfaces you should allow 24 hours to be safe. I don't think it will survive the journey from China.....

    Get one of those nebuilser sprays they use for cooling down in hot countries and fill it with 99.9% isopropyl alcohol and spray with that. Although it should evaporate almost immediately you should still allow plenty of time in a warm place for it to fully dry out just to be safe.

  • Hero Member

    @skywatch I'm not sure about this virus, but 99.9% IPA might evaporate too quickly to give the dwell time needed for effective disinfecting. If a quick misting and fast evaporation works though, then I'd be all in favor of that approach.

  • @NeverDie You may have a point, and with electronic items the addition of water to lower it to 'rubbing alcohol' levels would not be desireable.

    So best thing might be to still use 99.9% but spray item inside a zip-lok bag and seal it for an hour. Then open and dry in a warm ventillated area......Afterall, how long do those hand sanitiser gels stay around? They seem to be gone in a matter of seconds after rubbing hands with them.

  • Hero Member

    @skywatch That's why they're called sanitizers rather than disinfectants. The criteria is different. cleaner < sanitizer < disinfectant < sterilizer. Even with disinfectants, there are different "levels", with "high level" disinfectants doing the best job of killing. Technically speaking, what we most want is an effective virucide.

    At times it feels like we're living a science fiction novel, but really this is all pretty well understood by microbiologists and the like. For the rest of us don't live in that world day-in and day-out, though, I found this document, which is general in nature, to be useful in getting up to speed:

  • Don't overthink this, if extreme and immersive sterilisitation was essential why would humans be told to wash hands with soap for 20 secs, or alcohol>60% or dilute hypochlorite wipedowns be accepted as adequate for worktops... 😉

  • @NeverDie What really makes me laugh is the hoards of people buying up antibacterial soap. It is a corona "virus", not corona bacteria. What they should be getting is an antiviral, not anti bacterial!

  • Hero Member

    Here we're using 0.13% Benzalkonium chloride as our hand sanitizer. It doesn't dry the skin, and it still has killing power for supposedly up to 3 hours after it dries/evaporates. Big Clive mentions it in his video on DIY hand sanitizers:

    Emergency DIY hand sanitizers (read the description) – 07:02
    — bigclivedotcom

    Not that it matters much at the moment, since for now everyone is pretty much locked down at home and not going out. My entire neighborhood within auditory range has become eerily silent.... No one on the streets, and almost no traffic either. Over just a couple of days, the US has practically stopped, whereas even late last week some of my neighbors thought kids should stay in school or else the delays would wreck their summer plans. One even said that it was less deadly than the flu, because the flu had so far killed more people this year. How's that for logic? It's just amazing to me how some people can be so thick headed, even after I tried to relate to them what had already happened in Italy, and was sure to happen here soon if nothing was done, but there it is.

  • What I find bemusing is that it was in the absence of soap and water that I first came across gel sanitiser in war zones, but are folks really using both techniques in tandem nowadays ?
    The sad aspect of bulk buying of the stuff in Covid panic mode, has left many of the vulnerable prone due to resulting shortages, care homes a particularly concerning example...
    As further information on hand sanitisers, thought this a reasoned article...

  • Hero Member

    @zboblamont Good to know. So, maybe BAC isn't a good choice then. And too late to buy everclear, as that's now sold out everywhere. I rather not use IPA as a hand sanitizer, as suggested in the OP, but maybe that's all that's left.

    I think I'll stick with the peracetic acid for a disinfectant (it's not for use as a hand sanitizer though). From what I've read, as a disinfectant it's top notch.

  • Hero Member

    I just had 15 pounds of cheese delivered, and it's now sitting in it's own private quarantine drawer in the refrigerator. Anyone know how long the virus can survive on a plastic surface at, say, 36F (1C)? I think I read that the virus dies at high and low temperatures, but I'm just not sure how low is low, and for how long it needs to be. I think the 3 day rule may have been for ambient temperature (20C).

    I'm all googled out for now, so give a shout if you know the answer.

  • Hardware Contributor

    @hek we have plenty of hydro alcoholic gel available here in Vietnam, and they all contain ethanol and not IPA, which is a skin irritant and doesn't seem to be a good idea to use for hand sanitizer as you need high concentration for alcohol to be efficient on the virus. You should change the recipe of your "quick and easy" version, to use ethanol as recommended by WHO.

    For the survival of the virus new studies show a survival up to 3 days on some surfaces like inox. But that's the best case scenario for the virus, on most surfaces and in most conditions it seems it will just die in a matter of hours. So unless you have a very fast shipping (would be surprising with the number of international flights plummeting), you have nothing to fear.

    And now the main risk if you are in the US, EU etc is probably from the employees of the delivery company, as there are probably way more active cases in the US/EU than in China outside of the Hubei province. So when you receive a package, open it outside, get rid of the packaging, and if you're paranoid let it wait a few days in garage/storage room. Then wash your hands carefully, and you risk nothing.

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