# Expiration date on water ? **URL:** \ **Category:** Factual Questions\ **Created:** [September 24, 2000, 8:01am UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355 "2000-09-24T08:01:47Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Jorge](https://avatars.discourse-cdn.com/v4/letter/j/9fc29f/32.png) [@Jorge](https://boards.straightdope.com/u/Jorge)\ **Post date:** [September 24, 2000, 8:01am UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/1 "2000-09-24T08:01:47Z")
The bottle of “purified” water I got here has a stamped expiration date (“Best before 3/4/02”). The label claims less than 5 ppm dissolved solids, and that it’s [apparently tap] water put through reverse osmosis. Why would it expire ? From picking up plastic odors from the jug ? ---
**Author:** ![yojimbo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yojimbo/32/232_2.png) [@yojimbo](https://boards.straightdope.com/u/yojimbo)\ **Post date:** [September 24, 2000, 8:43am UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/2 "2000-09-24T08:43:53Z")
The [Bottled Water Web FAQ](http://www.bottledwaterweb.com/qna.html) says : > [@](#): > > You may notice that most bottled water containers sold at retail bear a two-year expiration date. This acts as a lot number and is for stock rotation purposes. It does not mean the product is substandard after that date. Thus, bottled water purchased in bulk is good indefinitely if stored appropriately ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [September 24, 2000, 9:55am UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/3 "2000-09-24T09:55:51Z")
- - - Maybe if you get water bottled in glass containers, with good lids it’s good indefinitely, but most I see is in plastic containers that very often don’t seal perfectly - namely the gallon-milkjug-type containers. These frequently have minute holes, especially around the seams. I’d bet that if you kept it long enough that it would grow algae eventually. - The store where I work occasionally skips the order for a day or two in order to sell out and clear the shelves; the dates on ours are 12 or 14 months, and we don’t sell them out of date. I haven’t found a jug older than about five or six months (but sometimes they reach us two months old already). - MC ---
**Author:** ![funneefarmer](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@funneefarmer](https://boards.straightdope.com/u/funneefarmer)\ **Post date:** [September 24, 2000, 9:20pm UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/4 "2000-09-24T21:20:31Z")
To throw one more link at you, which contains the same link that yojimbo has allready supplied… [SDMB - Shelf-life of bottled water](http://boards.straightdope.com/sdmb/showthread.php?threadid=12731) ---
**Author:** ![Lance\_Turbo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lance_turbo/32/6156_2.png) [@Lance\_Turbo](https://boards.straightdope.com/u/Lance_Turbo)\ **Post date:** [September 25, 2000, 6:40am UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/5 "2000-09-25T06:40:57Z")
> [@](#): > > \*Originally posted by Jorge \* > **"Best before 3/4/02"** That’s not a true expiration date, that’s a guidline for the store and the consumer. Plastic bottles do break down. The water you have will taste best before 3/4/02, and after that date it might taste a little more like plastic than one would want. Something that spoils easily will be marked, “Sell by …” or something similar. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [September 25, 2000, 3:14pm UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/6 "2000-09-25T15:14:24Z")
bacteria love to breed in bottled water. It’s their favorite breeding place. Bottled water has a lot more bacteria than your ordinary faucet water [which is in motion]… ---
**Author:** ![LazarusLong42](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@LazarusLong42](https://boards.straightdope.com/u/LazarusLong42)\ **Post date:** [September 25, 2000, 6:13pm UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/7 "2000-09-25T18:13:09Z")
> [@](#): > > \*Originally posted by handy \* > \*\*bacteria love to breed in bottled water. It’s their favorite breeding place. Bottled water has a lot more bacteria than your ordinary faucet water [which is in motion]… \*\* Um. No. In order for bacteria to breed, they have to have some source of food, usually sugar. Bacteria can’t breed in bottled water because it has no food source. I’ll give you that there might be more living bacteria in bottled water (they won’t die in there, even if they can’t reproduce), because tap water generally has chlorine in it to kill them. However, bottled water will never have algae in it, which tap water may, along with algae by-products such as methylisobornane. (My mother works as a chemist in a water plant. She won’t touch tap water any more, and she’s only worked there about nine months. You figure it out.) LL ---
**Author:** ![lawoot](https://avatars.discourse-cdn.com/v4/letter/l/35a633/32.png) [@lawoot](https://boards.straightdope.com/u/lawoot)\ **Post date:** [September 25, 2000, 7:33pm UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/8 "2000-09-25T19:33:56Z")
I took a class taught by one of the Denver Metro health Districts years ago, when I worked as a Domino’s Pizza manager. There is only ONE product that is required by law to have a TRUE expiration date: Baby Formula. All others are basically marketing scams to get you to buy more often… ---
**Author:** ![ren](https://avatars.discourse-cdn.com/v4/letter/r/ed655f/32.png) [@ren](https://boards.straightdope.com/u/ren)\ **Post date:** [September 25, 2000, 7:55pm UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/9 "2000-09-25T19:55:29Z")
I hardly consider the expiration date on a bottle of milk to be nothing more than a scam. ---
**Author:** ![Saltire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saltire/32/553_2.png) [@Saltire](https://boards.straightdope.com/u/Saltire)\ **Post date:** [September 25, 2000, 8:20pm UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/10 "2000-09-25T20:20:18Z")
If you are keeping bottled water for a long time, I guess you’d want to keep it in the dark. If it has any microbes in it (i.e. it isn’t distilled), some of them can photosynthesize sugars to live on if they have light. In that case, your water could go green on you. Still doesn’t seem like a lot of risk there, however. ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [September 25, 2000, 8:23pm UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/11 "2000-09-25T20:23:11Z")
The hard clear plastic water bottles are the only ones worth buying. The soft whitish translucent ones tend to contaminate the water more quickly. ---
**Author:** ![lawoot](https://avatars.discourse-cdn.com/v4/letter/l/35a633/32.png) [@lawoot](https://boards.straightdope.com/u/lawoot)\ **Post date:** [September 28, 2000, 6:33am UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/12 "2000-09-28T06:33:36Z")
> [@](#): > > \*Originally posted by ren \* > \*\*I hardly consider the expiration date on a bottle of milk to be nothing more than a scam. \*\* OK it’s not a scam… but it’s also NOT an expiration date… it’s a ‘sell by’ date, which is put on more for the benefit of the grocer, and not for the consumer. Milk is generally still good for a few days after that date (although that’s usually the date that I start doing the ‘sniff test’) ---
**Author:** ![AWB](https://avatars.discourse-cdn.com/v4/letter/a/bb73d2/32.png) [@AWB](https://boards.straightdope.com/u/AWB)\ **Post date:** [September 28, 2000, 12:30pm UTC](https://boards.straightdope.com/t/expiration-date-on-water/34355/13 "2000-09-28T12:30:45Z")
> [@](#): > > \*Originally posted by Jorge \* > \*\*The bottle of “purified” water I got here has a stamped expiration date (“Best before 3/4/02”). The label claims less than 5 ppm dissolved solids, and that it’s [apparently tap] water put through reverse osmosis. > > Why would it expire ? From picking up plastic odors from the jug ? \*\* After the expiration date, the hydrogen and oxygen bonds will fall apart. If you open in near an open flame – **KABOOM!** :D:D:D:D:D:D