How this instrument works
The World Health Organization published its Guide to Local Production: WHO-recommended Handrub Formulations in 2010, to help pharmacies and health facilities produce hand sanitizer locally, built on the technical background in the WHO's 2009 Guidelines on Hand Hygiene in Health Care. It specifies two formulations. Formulation I is ethanol-based: 8333 mL of 96% ethanol per 10-liter batch, for a final concentration around 80% ethanol. Formulation II is isopropanol-based: 7515 mL of 99.8% isopropyl alcohol per 10-liter batch, for a final concentration around 75% isopropanol. Both add 417 mL of 3% hydrogen peroxide and 145 mL of 98% glycerol per 10 liters, topped up with sterile or previously boiled water to the target batch volume.
Each ingredient has a specific job. The alcohol is the active antimicrobial component, effective against most bacteria and enveloped viruses at these high concentrations. The hydrogen peroxide isn't there to disinfect skin — it's included at a low concentration to help inactivate bacterial spores that might be present in the alcohol, glycerol, or containers used during production, and it isn't meant to remain active in the finished product at any meaningful level. The glycerol is a humectant: it moisturizes skin and offsets some of the drying effect of using a high-concentration alcohol repeatedly, which matters for whether people keep using it correctly rather than avoiding it.
This calculator only does the arithmetic of scaling the WHO's reference 10-liter recipe to any batch size — it doesn't replace the WHO's full production guidance on equipment, technique, and quality control. Mix only in a well-ventilated area, away from any open flame, stove, pilot light, or other heat or spark source — concentrated alcohol is flammable. Label containers clearly with contents and mixing date, and keep both the finished product and the raw ingredients out of reach of children. This recipe was designed for supervised local production with accurate measuring equipment; it is not a substitute for pharmaceutical-grade commercial sanitizer in clinical or other critical settings where quality assurance matters most.
- Enter the batch volume you want to produce, in liters.
- Choose the WHO formulation: Formulation I (ethanol) or Formulation II (isopropanol).
- Read off the alcohol, 3% hydrogen peroxide, 98% glycerol, and water volumes in mL, scaled to your batch size.
- Combine in a well-ventilated area away from any flame or heat source, following the WHO's local production guidance for equipment and technique.
Worked example — a 1-liter batch of Formulation I
Scaling the WHO's 10-liter ethanol recipe down to 1 liter: 8333 ÷ 10 = 833.3 mL of 96% ethanol, 417 ÷ 10 = 41.7 mL of 3% hydrogen peroxide, 145 ÷ 10 = 14.5 mL of 98% glycerol, and 1105 ÷ 10 = 110.5 mL of water — the same 80% final ethanol concentration the WHO specified, just resized to a smaller batch.
A full 10-liter batch of Formulation II instead calls for 7515 mL of 99.8% isopropyl alcohol, the same 417 mL of peroxide and 145 mL of glycerol, and 1923 mL of water — more water than Formulation I, because isopropanol is used at a slightly lower final concentration (about 75%) than ethanol (about 80%).
Questions
Why does the recipe include hydrogen peroxide if it isn't meant to disinfect skin?
It's there to help eliminate bacterial spores that could be present in the raw alcohol, glycerol, or the containers and equipment used during local production — a quality-control step for the manufacturing process, not an active ingredient in the finished handrub. It isn't intended to remain active in the final product at any meaningful concentration.
Why does Formulation II need more water than Formulation I?
The two formulations start from different alcohol concentrations (96% ethanol versus 99.8% isopropyl alcohol) and target slightly different final alcohol concentrations (about 80% versus about 75%). That difference in starting and target concentration is what changes how much water is needed to reach the correct final dilution for each.
Is WHO-formula hand sanitizer as effective as a commercial product?
Mixed accurately to the WHO's specified concentrations, it's considered effective against most bacteria and enveloped viruses. But effectiveness depends entirely on hitting the correct final alcohol concentration, which depends on accurate measurement and correct raw-ingredient strength — this recipe was designed for trained pharmacy or health-facility production with proper equipment, not as a casual improvised recipe. Pharmaceutical-grade commercial sanitizer remains preferable for clinical or other critical-use settings.
What alcohol concentration do the raw ingredients need to be?
Formulation I calls for 96% ethanol; Formulation II calls for 99.8% isopropyl alcohol. Using a lower-proof alcohol — for example, ordinary spirits — won't reach the WHO's intended final concentration and will produce a weaker, less reliable product.
Does the water in the recipe need to be sterile?
The WHO's guide specifies sterile distilled water or water that has been boiled and cooled, to reduce the chance of introducing microbial contamination during production, rather than untreated tap water.
Is it safe to mix this at home?
Mix only in a well-ventilated area, away from any open flame, stove, pilot light, or other spark or heat source, since concentrated alcohol is flammable. Label containers clearly with the contents and mixing date, and store both raw ingredients and the finished product out of reach of children. This WHO guidance was written for supervised local production in pharmacies and health facilities with accurate measuring equipment, not as an informal home project.
Can this replace commercial hand sanitizer during a shortage?
The WHO designed this guidance specifically for situations where commercial supply is limited, intended for production by pharmacies and health facilities following the full technique and quality-control steps in the guide — not just the ingredient ratios this calculator scales. For routine personal or household use when commercial product is available, that remains the simpler and more consistently quality-controlled option.
References
- World Health Organization — Guide to Local Production: WHO-recommended Handrub Formulations, WHO/IER/PSP/2010.5 (2010)
- World Health Organization — WHO Guidelines on Hand Hygiene in Health Care (2009)
Read this first: This instrument computes a screening figure from population formulas — it is not a diagnosis, and it cannot see the whole picture a clinician can. Use it to inform a conversation, not to replace one.