DIY Sanitizer – End alcohol % is NB

DIY Sanitizer – End alcohol % is NB

Stop buying all the toilet paper

Unless you’ve been living under a rock, which I mean is not physically possible so maybe on an isolated island, you should be aware of Covid-19 spreading all over the place. This has lead to people doing dumb things like buying up all the toilet paper. I mean I suppose its a priority for some but why not all the toothpaste? That’s also a stock-able item in case of the apocalypse. So if you’re out buying all these things. Stop. Its not fair to those who don’t have the means to stockpile.

Soap and isolation is the best defense

Wash your hands and stay away from hugging and kissing people, especially strangers. You should be doing that anyway, its weird to hug strangers. Soap (any soap) and water is the best option for keeping your hands free from the virus. This is because the soap takes all the microbes and viruses and encapsulates them and washes them off the surface of your skin. There is no need then to “kill” them since they’re just washed away. 20 seconds of washing is the recommended time.

Sanitizers or sanitisers

The second best thing you can do to keep clean is to use a sanitiser. This is for when you are out and about and just don’t have a place to wash your hands. The best choice is an alcohol based one because the Covid-19 virus has an envelope around it which is broken down by the alcohol. The non-alcohol based products have other ingredients as substitutes, like benzalkonium chloride, that are more effective against bacteria not enveloped viruses.

How hand sanitisers protect against infections. DIY sanitiser.
Compound chem made this great infographic

Another thing to remember is that oily dirty hands may inhibit the effectiveness of the sanitiser so this is a short term solution until you can go and wash your hands with soap.

The sanitiser needs to cover your skin and be “wet” for 20 seconds or so. Make sure you use enough.

DIY sanitisers – alcohol dose is NB

In RSA the virus has just started spreading and there has been a little bit of panic-buying leaving most stores with no sanitiser left. Soap is fine, like I said, but alas sanitisers are the favourite and sell out fast.

Essential oils will not protect you. I repeat, essential oils will NOT protect you. There is no evidence that tea tree oil and other essential oils will effectively denature the Covid-19 virus. There just hasn’t been enough time to do the studies. Alcohol has been studied many times with similar enveloped viruses and has proven to be effective. Trust the science not the social media influencers trying to sell you a product.

Now that doesn’t mean that if you have any amount of alcohol in the mixture, then its effective. It needs to be above 60% minimum to work. So these recipes using Vodka (40%) as an alcohol source are just not going to work. Your final concentration of alcohol is the important thing because it takes into account the final volume of liquid.

WHO DIY sanitiser recipe

The recipes I would trust and which seems to be the most cost effective are the ones recommended by WHO (World Health Organisation). These are liquid and used in a spray bottle.

Formula 1 – makes 1L

  1. Ethanol (96%) – 833.3 mL (End concentration of 80% in volume)
  2. Glycerine (gycerol) – 14.5 mL
  3. Hydrogen peroxide (3%) – 41.7 mL
  4. Top up to 1L mark with distilled water

Formula 2 – makes 1L

  1. Isopropanol (rubbing alchol/surgical spirits – 99.8%) – 751.5 mL (End concentration of 75% in volume)
  2. Glycerine (gycerol) – 14.5 mL
  3. Hydrogen peroxide (3%) – 41.7 mL
  4. Top up to 1L mark with distilled water

Another option is to use aloe vera as a carrier instead of glycerin but just remember your alcohol concentration is the most important part. Technically you could leave out the glycerine, however, the alcohol is very drying so if you do, remember to moisturize afterwards. If you reeeealy want to, you can add some fragrance with lavender oil etc but just a few drops which won’t drastically affect your end alcohol concentration.

The hydrogen peroxide is in there to protect the formula from bacterial contamination and doesn’t actually act as the sanitiser on your skin.

Keep your mixture in a closed spray bottle to prevent evaporation.

So just remember that washing your hands is the most important thing. Don’t touch your face and don’t buy up all the things in the shops. Just be calm and considerate. If you can’t find hand sanitiser and you feel you need it in your life, make your own DIY hand sanitiser but make sure its at least 60% alcohol based.


  1. Wired
  2. Labmuffin – there’s a great excel calculator you can use if you’re unsure.
  3. WHO

2 thoughts on “DIY Sanitizer – End alcohol % is NB

  1. Very helpful, the most basic and simple thing that your own mom, gran and great gran drummed into you “wash your hands before and after doing anything” and if in any doubt just go back and wash them again. AL

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