Making a Home-made Hand-sanitizer

During this COVID-19 crisis, we want to remain safe and healthy.

As such, making our own hand sanitizer is a nice way to prevent the spread of infection.

Let's understand the ingredient used in making a homemade hand-sanitizer.

1. Disinfectant (D)— the basic ingredient to outright destroy the cell walls of target microbes. It is usually a concentrated alcohol.

2. Humectant (H) — a chemical to maintain moisture on the skin to prevent dehydration from alcohol. Undiluted alcohol is flammable and can ignite with the heat produced on our skin. Also, it is highly volatile and vaporizes at around 17-19°C. Humectants reduce flammability and volatility.

3. Sterilant (S) — a chemical to prevent contamination of the basic ingredient from non-target microbes like spore-forming cryptosporidium, clostridium difficile and norovirus; all of which are remain alive in concentrated alcohol.

Any sanitizer will have a similar composition of chemicals having each of the basic properties.

Other additions are to either make the product user-friendly or to reduce the production cost. This includes fragrances that do not add anything to its antimicrobial activity.

I brought a laboratory grade hand-sanitizer; each costing ₹400 for 500 mL.

100g AHD (alcohol-based hand disinfection) special solution of the hand-sanitizer contained

• 75% v/v ethanol IP (denatured with acetone 0.5%) — D

• 2.5 % v/v chlorhexidine gluconate IP — S

• Glycerine, butane-2-one, macrogolglycerol cocoate, Lactic acid — H

The World Health Organization (WHO) has approved the following ingredients for making 1 L hand-sanitizers using distilled water,

• Ethanol 96% (833.3 mL; 80% v/v) or Isopropyl alcohol (rubbing alcohol) 99.8% (751.5 mL; 75% v/v) — D

• Hydrogen peroxide 3% (41.7 mL) — S

• Glycerol 98% (14.5 mL) — H

Herbal remedy experts crank it up a notch by adding naturally derived ingredients,

• Isopropyl alcohol 99% — D

• Aloe vera gel (added as 2:1 proportion of alcohol to Aloe Vera)— S

• Tea tree oil, lavender oil, clove oil, eucalyptus oil, lemon juice or vitamin E — H

It is reasonable to know why each ingredient is relevant in making a homemade hand-sanitizer.

While the disinfectant alcohol is the most important ingredient, presence of a humectant prevents the alcohol's corrosive action on our skin.

A sterilant is generally optional, but the sanitizer may develop spores if kept for long and harm us through alcohol-resistant microbial action.

If you are short of complex chemical ingredients, it is a good idea to maintain rubbing alcohol or ethanol composition between 60% and 95% v/v. This has been a proven effective range to destroy microbes on our skin.

A humectant can be substituted by using moisturizers like essential oils, or a chemist shop's hydrogen peroxide. The latter improves the sanitizer's longevity.