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Water purification with bleach
When boiling is not possible, ordinary unscented household bleach can disinfect water. Enter how much water you have.
The EPA table
| Water | 6% bleach | 8.25% bleach |
|---|---|---|
| 1 quart or 1 litre | 2 drops | 2 drops |
| 1 gallon | 8 drops | 6 drops |
| 2 gallons | 16 drops | 12 drops |
| 4 gallons | 1/3 teaspoon | 1/4 teaspoon |
| 8 gallons | 2/3 teaspoon | 1/2 teaspoon |
Double the amount if the water is cloudy, coloured or very cold.
Step by step
- If the water is cloudy, let it settle and filter it through a clean cloth, paper towel or coffee filter.
- Use regular, unscented chlorine bleach. Do not use scented or colour-safe bleach, or bleach with added cleaners.
- Add the drops with a clean dropper, stir, and let the water stand for 30 minutes.
- It should have a slight chlorine smell. If not, repeat the dose and wait another 15 minutes.
Bleach does not remove chemicals or heavy metals, and it works less well on cloudy water. If you can, boil water instead.
For planning and general information. In an emergency, follow the instructions of your local authorities and call your emergency number (911, 112, 999 or 000).