Infection control
WHO Hand Sanitizer Formula Calculator
Based on WHO-recommended formulations (2010). Combine ethanol or isopropyl alcohol with glycerin and sterile water to create hand rubs at 60–80% v/v alcohol. Mix only in well-ventilated areas away from flames and allow time for microbial spores to inactivate.
E.g., 96% ethanol or 99% isopropyl alcohol.
WHO recommends 60–80% v/v alcohol for effective hand rubs.
WHO formulation: 1.45% v/v glycerin (e.g., 15 mL per liter).
Optional 3% hydrogen peroxide (e.g., 42 mL per liter) helps inactivate spores in the solution.
Volumes (mL)
- Alcohol: 729.2
- Glycerin: 15
- Hydrogen peroxide: 0
- Sterile water: 255.8
Achieved alcohol concentration
72.9%
Target: 70%
Combine alcohol, glycerin, and sterile water in clean containers. Allow the mixture to rest at least 72 hours where possible.
Store in clean containers. Label with date/time, ingredients, and alcohol concentration. Keep away from children and flames.
How to Use This Calculator
Measure carefully
Use graduate cylinders or volumetric flasks for accurate measurements. Sanitize containers before use.
Add ingredients in order
Combine alcohol first, then hydrogen peroxide, glycerin, and finally sterile water. Mix gently with sterile stir bars or by inversion.
Let the mixture rest
WHO recommends a 72-hour quarantine period before bottling to allow spores to be destroyed by hydrogen peroxide.
Formula
Alcohol volume = (Final volume × Target alcohol %) ÷ Stock alcohol %
Water volume = Final volume − Alcohol volume − Glycerin − Hydrogen peroxide
All percentages are volume/volume (v/v). Ensure the final alcohol concentration remains between 60% and 80% v/v.
Full Description
Homemade alcohol-based hand rubs should follow WHO guidelines to ensure antimicrobial efficacy. The recommended formulations employ either 80% ethanol or 75% isopropyl alcohol, combined with glycerin to prevent skin irritation and hydrogen peroxide to inactivate bacterial spores in the solution.
Use caution: alcohol is flammable, hydrogen peroxide can irritate skin, and improper dilution may reduce efficacy. Commercially produced hand rubs are preferred when available. This calculator aids small healthcare facilities or laboratories in reproducing standardized recipes.
Frequently Asked Questions
Can I substitute other moisturizers for glycerin?
WHO recommends glycerin (glycerol). Substitutions can alter viscosity and antimicrobial activity; avoid unless validated.
Do I need hydrogen peroxide?
It helps eliminate spores in bulk preparation. If omitted, ensure containers and alcohol are sterile and use within a short timeframe.
Can I add fragrance or essential oils?
Fragrances may irritate skin and affect efficacy. If added, keep amounts minimal and ensure they are soluble in alcohol.
How should I store the final product?
Store in airtight containers at room temperature, away from heat and direct sunlight. Label with preparation date and concentration.