ShelfYears

Does bleach expire?

Yes — Clorox rates a bottle at one year from the day it was made, and since no expiration date is printed, the production code stamped on the neck is the only place that day appears.

Updated

Bleach
Sealed
About 1 year
Opened
About 1 year
HYPOCHLORITE BREAKDOWN
Degraded performance

Sealed: About 1 year Tier 1

Clorox's figure is one year: "Bleach will last for one year when stored in a cool dry place away from direct sunlight and heat." The clock starts at the production date on the bottle, not at the checkout. CloroxPro's own spec sheet backs it up, listing a 12-month shelf life for the 121 fl. oz. Clorox Germicidal Bleach bottle.

After opening: About 1 year Tier 1

The same number. Clorox says the one-year window "applies to both unopened and opened bottles" — the sodium hypochlorite decays into salt and water either way, and the cap is not what is holding it back. What an open jug on a warm, bright shelf loses is time: heat and direct sunlight get it to the same place sooner.

How to tell it's gone off

  • Read the production code on the neck of the bottle — it is the only date Clorox prints, and the decoder below turns it into a day.
  • A faint chlorine smell from the bottle where a fresh jug is sharp and unmistakable.
  • The liquid has gone from pale straw-yellow toward water-clear.
  • The code decodes to more than a year ago — that is Clorox's own cutoff for sanitizing and disinfecting.

If you use it anyway

Degraded performance

Old bleach fails quietly, which is the whole problem with it. Clorox's position is that out-of-date bleach "should not be used for any EPA registered disinfecting or sanitizing applications, but it can be used for cleaning" — the active has fallen too low to kill what it is meant to kill, while the bottle looks and pours exactly the same. Nothing is damaged and nothing becomes more dangerous. You simply do not get the disinfecting you thought you paid for.

Why it goes off — HYPOCHLORITE BREAKDOWN

Bleach is sodium hypochlorite in water, and sodium hypochlorite is unstable by nature — it comes apart into ordinary salt and water on its own, from the day it is bottled. Clorox's description of what happens at the one-year mark is that "the natural breakdown of the sodium hypochlorite bleach active into salt and water rapidly accelerates." Heat and sunlight move that along well before the date.

Every page here commits to one of four states — Harmless · Degraded performance · Equipment damage · Safety issue. How the verdicts work.

How to store it

Clorox's own terms: "a cool dry place away from direct sunlight and heat." A cupboard qualifies; a sunlit windowsill and a garage that swings from freezing to 100°F do not. There is no expiration date on the bottle by design — Clorox's reasoning is that "if the product isn't properly stored, an expiration date won't be accurate" — which is why the production code is there instead.

Never mix bleach with ammonia-based cleaners.

Reading the Clorox date code

Clorox stamps a production code on the neck of the bottle instead of an expiration date. CloroxPro reads it character by character: "The first two characters — A5 — are the code for the production facility. The third and fourth characters — 20 — are numbers that indicate the year of production, in this case 2020. The fifth, sixth and seventh characters — 064 — are numbers that indicate the day of production" on the Julian calendar, counted 1 to 365. Anything printed after those seven characters is line and time information, not part of the date.

Worked examples
Printed code Made on
A82223411 August 22, 2022
A520064 March 4, 2020

The decoded day is what's printed on the container — it tells you the product's age, nothing about this page. More formats.

Sources