How long does bleach last?
Household bleach keeps its full disinfecting strength for only about 6–12 months, so a bottle meant for treating water should be replaced at least once a year.
| Household Bleach | |
|---|---|
| Unopened | About 6–12 months at full strength |
| Opened | The same; it keeps weakening over time |
| Ideal storage | Cool and dark; heat speeds up its breakdown. |
Storage tips
- For water: use plain unscented bleach, 8 drops of 6% (or 6 drops of 8.25%) per gallon of clear water, and wait 30 minutes (EPA guidance).
- Never mix bleach with ammonia or acids.
Signs it has gone bad
- Batteries: white crusty residue, swelling or leakage at the terminals
- Bleach: a weak smell; it may no longer be strong enough to disinfect water
- Fuel: darker color, a sour or varnish-like smell, or separation into layers
- Canisters and cylinders: rust, dents, damaged valves or a gas smell