Hand Sanitiser: WHO-Recommended Alcohal Based Handrub Formulations

How to make Alcohol-based hand sanitizer

 

The basic components of an alcohol-based hand sanitizer:

  • Alcohol
  • Humectant/Emollient
  • Disinfectant

Alcohol

The major component of alcohol based formulation is, of course, alcohol. For this, the most commonly used is either 96% Ethanol or 99.8% Isopropyl alcohol. Of these, the easily available one is Isopropyl alcohol, otherwise known as Rubbing Alcohol. Please don’t use other types of alcohol (Methanol, Butanol, or others) since they are toxic.

Humectant/Emollient

Humectants are moisturizers that will help to prevent the drying of the skin. For WHO formulation, WHO recommends one that is miscible in water and alcohol, is non-toxic, or a hypoallergenic. A popular humectant that meets all these requirements is 98% Glycerol. You can also use other humectants such as Aloe Vera Gel.

Disinfectant

An effective disinfectant is added to this formulation to eliminate contaminating spores. An efficient choice is Hydrogen Peroxide. Its also a mild antiseptic as well as an oxidiser. Please keep in mind that the concentration of Hydrogen Peroxide should not exceed the recommended amount.

Hand Sanitiser Using WHO-Recommended Handrub Formulations

The following recipe is based on the guidelines for local production of WHO-recommended hand rubs formulations.

To make 1 L (1000 ml) Isopropyl alcohol-based hand sanitizer, you will need:

  • 8% Isopropyl Alcohol – 751.5 ml (approximately 3 US Cups and 3.5 US Table Spoons)
  • 3% Hydrogen Peroxide – 41.7 ml (approximately 2 US Table Spoons and 2.5 US Tea Spoons)
  • 98% Glycerol – 14.5 ml (approximately 1 Table Spoon, 1 tbsp = 14.7868 ml)
  • 3 ml Distilled Water or Cooled Boiled Water (approximately 3/4 of a US cup+ 1 US Table Spoon)

To make 1 L (1000 ml) Ethanol-based hand sanitizer, you will need:

  • 96% Ethanol – 833.3 ml (approximately 3.5 US Cups and 1 US Tea Spoons)
  • 3% Hydrogen peroxide – 41.7 ml (approximately 2 US Table Spoons and 2.5 US Tea Spoons)
  • 98% Glycerol – 14.5 ml (approximately 1 Table Spoon, 1 tbsp = 14.7868 ml)
  • 111 ml Sterile distilled or boiled cold water

Steps:

Mix all ingredients in a bowl thoroughly using a spoon or pour all ingredients into a glass or plastic bottle and mix by gently shaking the bottle.

Now close the bottle.

Keep the bottles closed for 72 hours before use. This allows time for Hydrogen Peroxide to destroy any spores present in the alcohol or the bottles used.

If you are making large quantities at one go, store in smaller containers of around 100 ml, so that the alcohol does not evaporate much with each time you use.

Some rubbing alcohols are made with Ethanol.

99.8% Isopropyl Alcoholimage

3% Hydrogen Peroxideimage

98% Glycerolimage

Some things to keep in mind:

Final concentrations:

Isopropyl Alcohol 75% (v/v) for Isopropyl based hand sanitiser and Ethanol 80% (v/v) for Ethanol-based hand sanitiser – (Please note that WHO based formula has a higher alcohol concentration).

Glycerol 1.45% (v/v)

Hydrogen peroxide 0.125% (v/v)

Do keep in mind that glycerol is very viscous. While measuring glycerol, the measuring cup should be rinsed with distilled or boiled and cooled water to be added and then emptied into the bottle.

Instead of glycerol, you can use aloe vera gel. Other humectants or emollients may be used for skin care, provided that they are mixable in water and alcohol, non-toxic, and hypoallergenic.

Since alcohols are highly flammable, store the ingredients and final formulation away from heat sources. Keep in mind that the flash points of isopropyl alcohol 75% (v/v) are 17.5°C and 19°C, respectively.

You may add essential oils that are you are not allergic to.

How to Use Hand Sanitiser

It’s important to mention that hand sanitisers are not the best method to prevent infection especially when your hands are dirty. The most effective method is to wash your hands thoroughly with soap for at least 20 seconds. To use hand sanitiser for the purpose of disinfectingfrom germs, rub hand sanitiser (just like how you wash your hands) over all the surfaces of your hands and fingers until your hands are dry. This should take around 20 seconds.

Steps:

Apply a palmful of the product in a cupped hand.

Cover all surfaces of your hand

Rub hands palm to palm

Right palm over left dorsum with interlaced fingers and vice versa

Palm to palm with fingers interlaced

Backs of fingers to opposing palms with fingers interlocked

Rotational rubbing of left thumb clasped in right palm and vice versa

Rotational rubbing, backwards and forwards with clasped fingers of right hand in left palm and vice versa

Once dry, your hands are safe

The whole process should take 20 to 30 seconds

If you are buying hand sanitiser for the sake of protection from coronavirus disease, make sure that it contains at least 60% alcohol. Many hand sanitisers available in the shops are alcohol-free with ingredients like benzalkonium chloride.

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