Disinfecting Water Using Household Bleach

If you cannot boil water, disinfecting it using household bleach is an effective alternative. This guide will explain how to safely disinfect water with bleach, the correct proportions, and considerations for safety and effectiveness.

Why Use Bleach to Disinfect Water?

Household bleach can be used to kill most harmful microorganisms, including bacteria and viruses, making water safer to drink when boiling is not an option.

  • Emergency Situations: Natural disasters or compromised water supplies may require an alternative method to boiling.
  • Effective Against Pathogens: Bleach can kill harmful bacteria, viruses, and some protozoa.
  • Widely Available: Unscented liquid chlorine bleach is commonly found in homes and stores.
How to Disinfect Water Using Bleach

Follow these steps to properly disinfect water with household bleach:

  1. Use Unscented Bleach: Ensure that the bleach contains 6% or 8.25% sodium hypochlorite and does not have added fragrances or cleaners.
  2. Filter Cloudy Water: If the water is cloudy, let it settle and filter it through a clean cloth, coffee filter, or paper towel.
  3. Measure the Correct Amount: Use a clean dropper to add the appropriate amount of bleach per gallon of water (see the table below).
  4. Stir and Let Stand: Stir well and let the water sit for at least 30 minutes. It should have a slight chlorine odor. If not, repeat the dosage and wait another 15 minutes.
  5. Reduce Chlorine Taste: If the chlorine taste is too strong, transfer the water between two clean containers and let it stand for a few hours before drinking.
Volume of Water Amount of 6% Bleach Amount of 8.25% Bleach
1 quart/liter2 drops2 drops
1 gallon8 drops6 drops
2 gallons16 drops (1/4 tsp)12 drops (1/8 tsp)
4 gallons1/3 tsp1/4 tsp
8 gallons2/3 tsp1/2 tsp
Limitations of Bleach Disinfection
  • Does Not Remove Chemicals: Bleach kills pathogens but does not remove heavy metals, pesticides, or other chemical pollutants.
  • Short Shelf Life: Liquid bleach degrades over time, especially if stored in warm conditions.
  • Requires Proper Measurement: Too much bleach can be harmful, while too little may not effectively disinfect the water.
FAQ About Using Bleach for Water Disinfection
  • Can I use scented bleach? No, only use unscented bleach labeled for disinfection.
  • Does bleach remove all contaminants? No, it only kills biological pathogens. Filtration is needed for chemical and particulate removal.
  • How long should I wait before drinking the treated water? At least 30 minutes. If the water is very cold, wait up to 60 minutes.
  • How do I know if the bleach worked? The water should have a slight chlorine smell. If not, repeat the process.
Helpful Resources
Alternative Filtering Methods & Related Pages