You already own a water purifier. It's in your laundry room.
Plain household bleach — the boring, unscented kind — is what the EPA itself points to for emergency water disinfection. The catch is that the math has to be right, and an emergency is a bad time to be searching for it on a dead phone. So here it is, worth reading twice now.
First, check the bottle
The label needs to say 6% or 8.25% sodium hypochlorite, and nothing else fancy. Per the EPA: no scented bleach, no color-safe bleach, no bleach with added cleaners. Those additives are fine for laundry and not fine for drinking. If the bottle in your laundry room is "mountain fresh" scented, put a plain one on the next grocery list.
The math
Per the EPA's emergency disinfection guidance:
| Water | 6% bleach | 8.25% bleach |
|---|---|---|
| 1 quart | 2 drops | 2 drops |
| 1 gallon | 8 drops | 6 drops |
| Cloudy, colored, or very cold | double it | double it |
Then stir it and let it stand for 30 minutes. The water should have a slight chlorine odor — that faint pool smell is how you know it worked. If it smells like nothing at all, the EPA says to repeat the dose and wait again.
A regular medicine dropper is the right tool here. Keep one taped to the bleach bottle and this whole page becomes a ten-second job.
When to boil instead
Bleach handles bacteria and viruses. But if you can boil, boil — it's the gold standard. Per the EPA: bring water to a rolling boil for one full minute, or three minutes above 5,000 feet. Let it cool on its own, then store it covered.
And know what neither method fixes: chemical contamination. If officials say the water has fuel or industrial runoff in it, no amount of bleach or boiling makes it safe. Stored water is the answer to that one — which is why the real move is storing enough now that you rarely need this chemistry at all.
The order of operations
When the tap becomes questionable, work down this list:
- Stored water first. It's already safe. That's the whole point of it.
- Boil if you have heat and the water is clear of chemicals.
- Bleach when boiling isn't an option.
- A quality filter covers the day-to-day taste and bacteria cases — see our water filter reviews for what each type actually removes.
Not sure how much stored water your household actually needs? Our free water calculator turns your household size into an exact gallon number in about a minute.