DIY (Do-It-Yourself) Hand Sanitizer Formula
for Coronavirus COVID-19

Based on World Health Organization (WHO) Formula

Due to the outbreak and spread of Coronavirus (COVID-19) disease, hand sanitizers are in short supply. You can easily make your own sanitizer using drugstore materials: alcohol, glycerin, and hydrogen peroxide.

This do-it-yourself (DIY) homemade hand sanitizer is based on a formula recommended by the World Health Organization (WHO) patient safety pamphlet Guide to Local Production: WHO-recommended Handrub Formulations. WHO is an agency of United Nations that promotes world-wide health.

Making hand sanitizer video
Watch the Video



To make one-third quart of hand sanitizer:

1 cup 99% isopropyl alcohol  -OR-  1 cup + 4 teaspoons 91% isopropyl alcohol
1 Tablespoon hydrogen peroxide 3%
1 teaspoon glycerin
Water to make a total of 1 and 1/3 cups (1/3 quart)

Watch the Video



To make one quart of hand sanitizer:

3 cups 99% isopropyl alcohol  -OR-  3.25 cups 91% isopropyl alcohol
3 Tablespoons hydrogen peroxide 3%
1 Tablespoon glycerin
Water to make a total of 4 cups (1 quart)



To make 320 ml of hand sanitizer:

240 ml 99%  -OR-  265 ml 91% isopropyl alcohol
15 ml hydrogen peroxide 3%
5 ml glycerin
Water to make a total of 320 ml



To make 1 liter of hand sanitizer:

750 ml 99%  -OR-  830 ml 91% isopropyl alcohol
40 ml hydrogen peroxide 3%
15 ml glycerin
Water to make a total of 1000 ml (1 liter)



Mixing Instructions

  1. Put on glasses or goggles to protect your eyes in case of accidental splashing.
  2. Combine the first three ingredients in a container.
  3. Add clean water to reach the target volume.
  4. Mix thoroughly by stirring or shaking.
  5. Pour the mixture into dispensing bottles.
  6. Label each dispensing bottle "Hand Sanitizer 75% Alcohol".

If your water is not absolutely clean, first boil it and allow it too cool to room temperature. If your containers and ingredients are not absolutely clean, allow 72 hours for the hydrogen peroxide to kill any spores present, and keep the solution away from sunlight and UV light, which break down the hydrogen peroxide.

The consistency of the final product is a liquid, not a gel. A spray bottle is useful for applying the sanitizer to your hands without dripping. Be sure to direct the spray at your hands. Label the container and keep it away from anyone who might misuse it.

More Videos:

Scaling Math: WHO Hand Sanitizer Formula Home Use
91% Isopropyl Alcohol Usage (Calculate Amount to Use)
70% Isopropyl Alcohol Usage (Do Not Add Water)
Ethanol 180 & 140 Proof (Calculate Amount to Use)

Derivation of Reduced Formula

Exact WHO formula to make 10 liters:

Isopropyl alcohol 99.8%: 7515 ml
Hydrogen peroxide 3%: 417 ml
Glycerol 98%: 145 m

Water to make 10000 ml (10 liters)


To make 320 ml, multiply all quantities by 320/10000:

alcohol: 7515 ml x .0320 = 240 ml = about 1 cup (237 ml)
Hydrogen Peroxide 3%: 417 ml x .0320 = 13.3 ml = about 1 tablespoon (15 ml)

glycerin: 145 ml x .0320 = 4.6 ml = about 1 teaspoon (5 ml)
water to make:  10000 ml x .0320 = 320 ml = about 1/3 quart (315 ml)

To make 1 liter, multiply all quantities by 1000/10000 or 0.1

To make 1 quart, multiply all quantities by 946/10000 or .0946 (a quart is 946 ml)

To make X ml, multiply all quantities by X/10000

If you are using isopropyl alcohol that is less than 100%, adjust the amount that you use such that the pure alcohol content is the same. For example, if the recipe calls for 750 ml pure alcohol (to make 1000 ml of sanitizer), and you are using 91% alcohol to start:

750 ml = .91X

X= 750/.91 = 824 ml

In this case you would use less water at the end to achieve the same 75% alcohol content for the final 1000 ml of sanitizer.

If using ethanol instead if isopropyl alcohol, WHO's formula calls for 80% ethanol content instead of 75%.

Ethanol 96%: 8333 ml
Hydrogen peroxide 3%: 417 ml
Glycerol 98%: 145 ml
Water to make 10000 ml

About the Ingredients

Isopropyl alcohol (also known as rubbing alcohol and isopropanol) is the ingredient that kills germs. It is sold in drugstores at different strengths, typically 70%, 91%, and 99%. The target strength for the hand sanitizer is 75%, so you need to start with at least the 91% strength product.
Note: Do not use 99% alcohol directly as hand sanitizer. Some water is needed for the sanitizer to work. The final product must be between 60% and 95% alcohol, per CDC Guideline for Hand Hygiene in Health-Care Settings
Glycerin (also known as glycerol) is a clear, thick liquid used as a moisturizer in skin care products and as a food igredient. It helps prevent your hands from drying out. You can it in the drugstore with other skin care products, and in health food stores.

Hydrogen peroxide 3% is an antiseptic sold in drugstores with other disinfectants. The small amount used in the formula is not effective for sanitizing the skin. Its purpose to kill any spores in the hand sanitizer itself, as alcohol is not effective against spores.

The WHO pamphlet recommends that you not add any other ingredients such as fragrances or gelling agents. Some home formulations use aloe vera gel, which might be OK, but it has not been evaluated for possible interactions with other ingredients.

The formulas for making 1 quart, 1/3 quart, 320 ml, and 1 liter of hand sanitizer are the same as the WHO formula, but with the amounts scaled down for single-family use.

The final ingredient target concentrations are:
Ethanol (also known as ethyl alcohol or grain alcohol), the alcohol in liquor, is an alternative ingredient that is not as easily available as isopropyl alcohol. Note that hard liquors are typically 80 to 100 proof (40% to 50% alcohol), too weak to work as hand sanitizer. If you plan to use ethanol instead of isopropyl alcohol, see the original WHO pamphlet for the formula.

Effectiveness of the WHO Formula

The Centers for Disease Control and Prevention (CDC) recommends ordinary soap and water for washing hands at home. Use alcohol-based hand sanitizers only when soap and water are not available.

Use the DIY hand sanitizer like any other. Apply enough to wet your hands thoroughly. Gently rub all surfaces of both hands, including fingertips and nails, until the alcohol evaporates. The CDC provides hand sanitizer usage and safety information.

CDC research has shown a hand sanitizer must be 60% to 95% alcohol by volume to be effective. Most commercially sold sanitizer products are 62% alcohol. The 75% strength used in this formula is even more effective against viruses.
Note: Alcohol is a fuel. For fire safety information, see the WHO formula pamphlet.
Disclaimer from WHO: "All reasonable precautions have been taken by the World Health Organization to verify the information contained in this document. However, the published material is being distributed without warranty of any kind, either expressed or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event shall the World Health Organization be liable for damages arising from its use."

Other Formulas on the Web

Many hand sanitizer formulas on the Internet use too little alcohol to achieve the required 60% minimum for effectiveness.

In the WikiHow article How to Make Gel Alcohol Hand Sanitizer, Method 1 is generally good, although usage of aloe vera gel has not been evaluated for possible interactions with the alcohol. Method 2 adds essential oils that have no sanitizing benefit. Method 3 uses 80 proof vodka as an ingredient, which is only 40% alcohol to start, and dilutes it using 3 parts aloe vera gel to 1 part vodka, resulting in a final 10% alcohol content.

The syracuse.com article Coronavirus supplies: How to make hand sanitizer with ingredients you have at home calls for 2/3 cup isopropyl alcohol 91% and 1/3 cup aloe vera gel. Later it says that this mixture is 65% alcohol, which would be correct if 99% alcohol were used. The actual percentage is 61% when mixed as directed.

The Good HouseKeeping article How To Make A Natural Hand Sanitizer With 3 Simple Ingredients uses plain vodka as an ingredient, diluted 3:1 by aloe vera gel and other ingredients. Most vodkas are 80 proof or 40% alcohol, so the resulting mixture is only 12% alcohol.

The Live Simply article DIY Hand Sanitizer uses 2 parts rubbing alcohol (no strength specified) and 3+ parts other ingredients. Even if 100% alcohol is used, the final mixture is only 40% alcohol.
 
For more information on hand sanitizer composition, see the Hand Sanitizer WikiPedia article.

References

WHO: Coronavirus Disease (COVID-19) Outbreak
Guide to Local Production: WHO-recommended Handrub Formulations
NCBI Data on WHO-recommended Handrub Formulations
Emerging Infectious Diseases Hand Sanitizer Alert



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