Disinfecting Water with Household Bleach
Measured, unscented bleach can disinfect clear water when boiling isn't possible.
Question 1
The goal
Disinfect clear water using chemicals available in most homes.
Question 2
Materials
- Unscented liquid chlorine bleach (6–8.25% sodium hypochlorite)
- Eyedropper
- Clean container
Question 3
Substitutes
- Purpose-made chlorine dioxide tablets
- Iodine tablets (not for pregnancy or thyroid conditions)
Where to find it
| Material | Household | Wilderness | Urban / scavenged |
|---|---|---|---|
| Unscented bleach | Laundry room (check label & date) | Pack purification tablets instead | Grocery, pharmacy, hardware store |
| Eyedropper | Medicine dropper | Measured cap from tablet kit | Pharmacy |
Question 4
Step by step
- 1
Check the label: unscented, no added cleaners, 6% or 8.25% sodium hypochlorite.
- 2
Filter or settle cloudy water first — chlorine works poorly in murky water.
- 3
Add 8 drops (6%) or 6 drops (8.25%) per gallon of clear water. Double for cloudy or very cold water.
- 4
Stir and wait at least 30 minutes.
- 5
Smell it: a faint chlorine odor means it worked. If not, repeat the dose and wait another 15 minutes.
Saved steps go to My Survival Notebook.
Question 5
The science
Hypochlorous acid oxidizes cell membranes and enzymes of microorganisms. Organic matter consumes chlorine, which is why clear water matters.
Question 6
Dangers & limits
- Never use scented, splash-less or color-safe bleach.
- Does not reliably kill Cryptosporidium.
- Does not remove chemical contamination.
Question 7
How you know it worked
A faint chlorine smell remains after 30 minutes.