Does Bottled Water Expire?

No. According to FDA there is no limit to the shelf life of bottled water, as long as it was produced properly and stays unopened.

FDA does not require an expiration date on bottled water either. The dates you see are voluntary, added by manufacturers to manage inventory rather than to tell you when the water stops being safe.

So a sealed bottle in a cool cupboard is fine long past whatever is stamped on it. That is the direct answer, and it is where almost every other page stops.

The question underneath

If water does not expire, why does every preparedness guide tell you to rotate it every six months?

Because that rule is not about water. It is about your container and your fill.

CDC’s six month figure applies to water you bottled yourself. It assumes a clean food-grade container, treated municipal water going in, and cool dark storage. What can go wrong is the seal, the container, and whatever got in at filling time and has had six months to multiply. None of that applies to a factory-sealed bottle filled under controlled conditions.

Same substance. Different confidence about the container. That is the entire difference, and once you see it the rule stops being arbitrary.

Heat is the real expiry date

If anything genuinely ends the life of stored water, it is temperature.

Plastic is slightly permeable, and heat accelerates everything: leaching from the container into the water, degradation of the plastic itself, and any biological activity inside. Consumer Reports cites a study finding that at 167°F, antimony leaching exceeded FDA limits within five days. Set against EPA’s actual limit, that temperature is a closed car rather than a cupboard.

That is a hot car, not a cupboard. But it establishes the direction, and it is why the same case of water is a different proposition in a basement and in a metal shed in August. Heat is also why the industry’s own advice is to store bottled water in a cool place away from household chemicals, since permeable plastic can pick up what is stored beside it.

If your water lives somewhere hot, the honest answer is to move it rather than to pick a date for it.

What actually goes wrong

Seals fail on containers that have been moved, stacked or knocked. A drum that has been full for three years may have a lid that no longer seals, and you will not know until you look.

Light grows algae. A clear container on a sunny shelf grows things an opaque one in the dark never will.

Contamination at filling. If it went in dirty, six months is generous. This is why treating at the fill matters more than treating at the drink.

People forget. By a wide margin the most common failure. Water gets stored once, the household feels prepared, and four years later nobody has checked a seal or turned over a container.

Rotate for the containers, not the water

The useful reframe: you are not rotating because the water went bad. You are rotating because it proves the system works.

Turning over a container tells you the seal still holds, the spigot still turns, the plastic has not gone brittle and the whole thing is still where you think it is. That is worth knowing on an ordinary Saturday rather than during an outage.

This is also why the published intervals contradict each other so badly: they are hedges against your container, not measurements of your water. Use the old water on the garden and refill. It costs nothing and it is the only test you will ever run on your own supply.

Put in your containers

Enter what you have and when it was filled, and this returns the date each one is due, along with which ones are already past it. Commercially bottled water is handled separately, because it does not follow the same rule.

Print the list, or put the dates in a calendar. The failure mode here is not chemistry. It is memory.