Here are the quantities recommended by WHO for The Better (Spray) Recipe

• Isopropyl alcohol
• Glycerol or glycerin
• Hydrogen peroxide
• Distilled water
• Spray bottle

Mix 340gram fluid of alcohol with 2 teaspoons of glycerol – glycerol is an important ingredient because it keeps the alcohol from drying out your hands. If you can’t find glycerol, proceed with the rest of the recipe anyway and just remember to moisturize your hands after applying the sanitizer.

Mix in 1 tablespoon of hydrogen peroxide, then 85grams fluid of distilled or boiled (then cooled) water. Load the solution into spray bottles—this isn’t a gel, it’s a spray. You can wet a paper towel with it as well and use that as a wipe.

Note: if by any chance you choose to work with a lower-concentration solution of rubbing alcohol, use far less water; remember, at least ¾ of your final mixture has to be alcohol.)

If you must, you can add in a splash of essential oil to your concoction to make it smell nice. Just don’t use lavender. Everyone else uses lavender, and your sanitizer is superior. [Source: WIRED]