How It Works
This scaler works in 4 steps.
Enter the reference formulation
Type each component and volume, or select a stored validated formulation.
Enter the reference batch volume
Type the batch size the formulation states, such as 10 L.
Enter the new batch volume
Type the batch to prepare, such as 1 L or 5 L.
Read the scaled recipe
The scaler returns each component volume and the final fill step.
The Formula
The formula multiplies every component by the same scale factor.
s = V_new / V_refVᵢ,new = Vᵢ,ref × sWater to V_new after all components- s:
- Scale factor
- V_ref / V_new:
- Reference and new batch volumes
- Vᵢ:
- Volume of component i
Scaling the WHO Formulation 1 from 10 L to 1 L (s = 0.1) gives 833.3 mL ethanol 96%, 41.7 mL hydrogen peroxide 3%, and 14.5 mL glycerol 98%, filled to 1,000 mL with water.
Conversion Table
The conversion table scales WHO hand rub Formulation 1 from the 10 L reference to 1 L, 500 mL, and 5 L.
| Component | 10 L reference | 1 L batch | 500 mL batch | 5 L batch |
|---|---|---|---|---|
| Ethanol 96% | 8,333 mL | 833.3 mL | 416.6 mL | 4,166 mL |
| Hydrogen peroxide 3% | 417 mL | 41.7 mL | 20.85 mL | 208.5 mL |
| Glycerol 98% | 145 mL | 14.5 mL | 7.25 mL | 72.5 mL |
| Sterile distilled or boiled cold water | To 10 L | To 1 L | To 500 mL | To 5 L |
Source: WHO Guide to Local Production of WHO-recommended Handrub Formulations. Follow the full guide for quality control steps.
What Is the Sanitizer Formulation Scaler?
The Sanitizer Formulation Scaler is a tool that scales a specified, validated formulation to a new batch size while keeping every component in the same proportion. The scaler multiplies each component by the ratio of the new batch volume to the reference batch volume.
Validated formulations, such as the World Health Organization (WHO) hand rub Formulation 1 (final 80% v/v ethanol, 1.45% v/v glycerol, 0.125% v/v hydrogen peroxide), state component volumes for a 10 L reference batch. The scaler reproduces that recipe at any size and keeps the make-to-volume step. Changing components or proportions changes the formulation, so the tool scales only.
Common Uses
There are 5 main uses of this scaler.
Local hand rub production
Facilities produce WHO formulations at the size they need.
Pilot batches
Producers make small test batches of a validated recipe.
Hospital pharmacy
Pharmacy teams scale compounding records.
Training batches
Trainers prepare 500 mL demonstration batches.
Production planning
Planners compute raw material needs per batch size.