Tools needed

• A mixing container large enough for the total volume
• A liquid measure that can measure the amounts accurately
• A funnel
• A permanent marker and labels or tape
• Small, clean bottles (a spray top works well)

Preparation Instructions

1. Carefully measure the alcohol and pour it into the mixing container.
2. Carefully measure the hydrogen peroxide and pour it into the mixing container.
3. Carefully measure the glycerol / glycerin and pour it into the mixing container.
4. Carefully measure the sterile water. Do not exceed the amount listed. Pour it into the mixing container.
5. Stir well.
6. Immediately divide up the solution into its final containers (e.g. 500 ml or 100 ml plastic bottles) and place the bottles in quarantine for 72 hours before use. This allows time for any spores present in the alcohol or the new/re-used bottles to be destroyed.

• WHO-recommended handrub formulation
• For external use only
• Avoid contact with eyes
• Keep out of the reach of children
• Date of production and batch number
• Use: Apply a palmful of alcohol-based handrub and cover all surfaces of the hands. Rub hands until dry
• Composition: ethanol or isopropanol, glycerol and hydrogen peroxide
• Flammable: keep away from flame and heat

• The recipe starts with alcohol rather than total volume, since alcohol is more likely to be in limited supply.
• Final strength: Final strength (alcohol percentage by volume) is based on WHO guidelines of 75% for isopropyl or 80% for ethanol.
  • If starting with 70% or isopropyl or 75% ethanol, the final strength target is reduced to 65% to 70%, still above the 60% minimum recommended by the CDC
• Rounding: Metric calculations are rounded to milliliters or grams.
  • Many households don't have more precise measurement tools.
  • Small rounding differences or measurement errors will still produce an effective product, since the targets are well above the 60% minimum.

• Total volume calculation: total_volume = alcohol_volume * alcohol_percentage / final_strength
  • For example, 473 (ml isopropyl) * 0.91 (91%) / 0.75 (75% strength) = 573.9, rounded to 574
• Hydrogen peroxide calculation: total_volume * 0.0417 (4.17%).
  • This produces the final recommended percentage of 0.125% peroxide
  • 0.0417 (4.17%) * 0.3 (3% hydrogen peroxide) = 0.001251 (0.1251%)
• Metric weight: the calculations are done in milliliters, then converted to grams based on density.
  • Alcohol volume depends on temperature, so we assume 20°C / 68°F
    • Total weight is based on weight of alcohol plus the weight of the remaining water
    • Formula: (alcohol_volume * alcohol_percentage * density) + ( alcohol_volume * (1 - alcohol_percentage) )
    • Isopropyl density: 0.7854 g/ml
    • Ethanol density: 0.7892 g/ml
    • Ethanol density at 32°C / 90°F is 0.77927 g/ml, so for 1000 ml of 91% alcohol, it would weigh about 9 grams less than at 20°C / 68°F, about a 1% difference which seems acceptable at this scale.
  • Hydrogen peroxide weighs 1.45 g/ml. Since this uses a 3% solution (97% water) it weighs 1.0135 g/ml, close enough not to need conversion for the small amounts.
  • Glycerol / glycerin weighs 1.26 g/ml.
  • Water weighs 1 g/ml, so no conversion is necessary.