# Why shouldn't I reuse a water bottle? **URL:** \ **Category:** Factual Questions\ **Created:** [September 17, 2009, 9:02pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499 "2009-09-17T21:02:44Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![jebert](https://avatars.discourse-cdn.com/v4/letter/j/ec9cab/32.png) [@jebert](https://boards.straightdope.com/u/jebert)\ **Post date:** [September 17, 2009, 9:02pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/1 "2009-09-17T21:02:44Z")
I’ve heard that one should not reuse the plastic bottles used for bottled water. Why not? After all, the original water came in the bottle. If there’s any problem with stuff leaching from the bottle into the water, it wouldn’t matter if it was the original water or replacement water. If there is some problem with germs, as long as the original user is the one reusing the bottle, it would be the same germs the original user deposited in the first place. So, What’s the deal? ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [September 17, 2009, 9:25pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/2 "2009-09-17T21:25:30Z")
I’d say you have a good handle on the answer. Make sure it’s washed out well enough that bacteria don’t grow there, and there’s no problem. If you’re asking why some people _say_ that you shouldn’t re-use them, I’ve heard some mumbo jumbo about plasticizers (actually, just about “chemicals”) leaching out, but of course you’re right - there would be more leaching when the bottle is new. ---
**Author:** ![MarcusF](https://avatars.discourse-cdn.com/v4/letter/m/67e7ee/32.png) [@MarcusF](https://boards.straightdope.com/u/MarcusF)\ **Post date:** [September 17, 2009, 9:28pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/3 "2009-09-17T21:28:00Z")
I looked into this a few years back. There was a big scare on this, you know the stuff, we’re all doomed, your kids will die, you’ll turn into a hermaphrodite, etc, etc. It’s a while back and I’m working from memory but I traced the scare back to a couple of studies. One that suggested chemicals leach out of bottles when they’re washed and another that suggested a build up in harmful bacteria with reuse. Further checking showed that the washing research was using extremely high temperatures - much higher than domestic hot water - and the bacteria build up was from a study into Canadian pre-schoolers with all round dodgy hygiene habits. I may be misremembering the details but I know my conclusion was that there was no good reason for not reusing water bottles a reasonable number of times. Hope this helps - if you want to bother I’m sure you could find the same studies. ---
**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\ **Post date:** [September 17, 2009, 9:31pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/4 "2009-09-17T21:31:36Z")
This link may help reassure you that the above posts are accurate: [http://www.plasticsinfo.org/s\_plasticsinfo/sec\_level2\_faq.asp?CID=705&DID=2839](http://www.plasticsinfo.org/s_plasticsinfo/sec_level2_faq.asp?CID=705&DID=2839) ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [September 17, 2009, 9:39pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/5 "2009-09-17T21:39:10Z")
I was under the impression that the big scary news was encouraged by those who sell bottled water. If everyone re-used their bottles four or ten times, that would represent a dangerous drop in original sales. ---
**Author:** ![Justin\_Credible](https://avatars.discourse-cdn.com/v4/letter/j/a8b319/32.png) [@Justin\_Credible](https://boards.straightdope.com/u/Justin_Credible)\ **Post date:** [September 17, 2009, 9:44pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/6 "2009-09-17T21:44:18Z")
Uh-oh. I’ve been using the same water bottle for months and I’ve never washed it. Maybe it’s time for a new one. ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [September 18, 2009, 5:22am UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/7 "2009-09-18T05:22:43Z")
> [@DrFidelius](#): > > I was under the impression that the big scary news was encouraged by those who sell bottled water. If everyone re-used their bottles four or ten times, that would represent a dangerous drop in original sales. This times 100. It’s the same as “why can’t unopened Cocacola bottles be carried through airport security by a traveler:” it’s got nothing to do with it being a corrosive liquid and everything with being able to sell it to you at much-higher prices once you’re past security. I’m currently at Uni and the only item of food and drink officially permitted into (some) classrooms is bottled water. If I bought it I’d be plonking down $2/day into bottled water. On a student’s budget, it ain’t gonna happen. ---
**Author:** ![Superhal](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Superhal](https://boards.straightdope.com/u/Superhal)\ **Post date:** [September 18, 2009, 5:26am UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/8 "2009-09-18T05:26:07Z")
I heard they deteriorate over time, but if anybody has a definitive answer that would be great. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [September 18, 2009, 6:24am UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/9 "2009-09-18T06:24:23Z")
I’ve been using the same 20 oz. bottles for several years. I refill them from gallon jugs, after rinsing them with hot water. ---
**Author:** ![Floater](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Floater](https://boards.straightdope.com/u/Floater)\ **Post date:** [September 18, 2009, 10:12am UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/10 "2009-09-18T10:12:13Z")
> [@Justin\_Credible](#): > > Uh-oh. I’ve been using the same water bottle for months and I’ve never washed it. Maybe it’s time for a new one. > [@panache45](#): > > I’ve been using the same 20 oz. bottles for several years. I refill them from gallon jugs, after rinsing them with hot water. I’ve used the same plastic bottle for years. I never rinse it with hot water and I just refill it with tap water. No problems. ---
**Author:** ![Serenata67](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/serenata67/32/10646_2.png) [@Serenata67](https://boards.straightdope.com/u/Serenata67)\ **Post date:** [September 18, 2009, 1:50pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/11 "2009-09-18T13:50:57Z")
I should show the girls at work this… they think I’m weird for re using my Gatorade bottles. They’re big and work well for me! ---
**Author:** ![cjepson](https://avatars.discourse-cdn.com/v4/letter/c/a9adbd/32.png) [@cjepson](https://boards.straightdope.com/u/cjepson)\ **Post date:** [September 18, 2009, 3:19pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/12 "2009-09-18T15:19:57Z")
> [@Serenata67](#): > > I should show the girls at work this… they think I’m weird for re using my Gatorade bottles. They’re big and work well for me! I’m happy for you, but what about the Gatorade bottles? ---
**Author:** ![HorseloverFat](https://avatars.discourse-cdn.com/v4/letter/h/8e8cbc/32.png) [@HorseloverFat](https://boards.straightdope.com/u/HorseloverFat)\ **Post date:** [September 18, 2009, 3:47pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/13 "2009-09-18T15:47:25Z")
> [@](#): > > [http://www.plasticsinfo.org/s\_plasti...D=705&DID=2839](http://www.plasticsinfo.org/s_plasti...D=705&DID=2839) A link from the plastic industry. Pardon me if I’m a little skeptical. Yes, reuse is generally safe but its important that they dont mention putting these things in dishwashers or other stresses. While I think these things are generally safe for adults, the controversy is about washing them with strong chemicals and exposing them to heat in a dishwasher or microwave, something that they arent designed to handle and never are exposed to when bought new. If you read more about this stuff you’ll see terms like “typical use conditions.” Guess what? Reusing a polycarbonite bottle for months isnt typical use. > [@](#): > > Why not? After all, the original water came in the bottle. They dont offgas much until they age or are stressed. So its safe at first but then potentially becomes toxic. A canadian study found bisphenol A, which isnt being caused by bacterial as suggested by the link above. Essentially youre taking a chance with BPA. Perhaps moreso in children than adults, but there controversy rages on for a reason. I avoid reusing anything with recycling code 7 on the bottom because those have a higher chance of releasing BPA. Granted, thats being extra careful, but from what I have read there’s alot of research to be done to decide one way or another. Considering a quality plastic bottle thats not polycarbonate costs like a dollar, why reuse this potentially dangerous junk? [From wikipdia](http://en.wikipedia.org/wiki/Bisphenol_A#Human_exposure_to_bisphenol_A): > [@](#): > > Bisphenol A has been known to leach from the plastic lining of canned foods[66] and, to a lesser degree,[citation needed] polycarbonate plastics, especially those that are cleaned with harsh detergents or used to contain acidic or high-temperature liquids. A recent Health Canada study found that the majority of canned soft drinks it tested had low, but measurable levels of bisphenol A.[67] While most exposure is through diet, exposure can also occur through air and through skin absorption.[68] > > Studies by the CDC found bisphenol A in the urine of 95% of adults sampled in 1988–1994[69] and in 93% of children and adults tested in 2003–04.[70] Infants fed with liquid formula are among the most exposed, and those fed formula from polycarbonate bottles can consume up to 13 micrograms of bisphenol A per kg of body weight per day (μg/kg/day; see table below).[71] The most sensitive animal studies show effects at much lower doses, while the EPA considers exposures up to 50 µg/kg/day to be safe.[38][72] In 2009, a study found that drinking from polycarbonate bottles increased urinary bisphenol A levels by two thirds, from 1.2 micrograms/gram creatinine to 2 micrograms/gram creatinine.[73] > > Consumer groups recommend that people wishing to lower their exposure to bisphenol A avoid canned food and polycarbonate plastic containers (which shares resin identification code 7 with many other plastics) unless the packaging indicates the plastic is bisphenol A-free.[74] The National Toxicology Panel recommends avoiding microwaving food in plastic containers, putting plastics in the dishwasher, or using harsh detergents, to avoid leaching.[75] ---
**Author:** ![Serenata67](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/serenata67/32/10646_2.png) [@Serenata67](https://boards.straightdope.com/u/Serenata67)\ **Post date:** [September 18, 2009, 4:06pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/14 "2009-09-18T16:06:40Z")
> [@cjepson](#): > > I’m happy for you, but what about the Gatorade bottles? They like the feeling of being full again… teehee… 😃 ---
**Author:** ![Captain\_Awesome](https://avatars.discourse-cdn.com/v4/letter/c/a698b9/32.png) [@Captain\_Awesome](https://boards.straightdope.com/u/Captain_Awesome)\ **Post date:** [September 18, 2009, 4:54pm UTC](https://boards.straightdope.com/t/why-shouldnt-i-reuse-a-water-bottle/510499/15 "2009-09-18T16:54:03Z")
The FDA considers bottled water to be ‘safe indefinitely’, including reviewing the potential for hazardous chemicals to migrate into the water with time. Such plastics (typically polyethylene terephthalate, or PET) don’t contain bisphenol A (BPA). However, there has been some recent [research](http://www.abc.net.au/science/articles/2009/04/29/2555698.htm) outlining the potential for estrogen-like compounds to leach from PET bottles. These levels are small, but the long term effects on human health have yet to be quantified. You are much safer, with respect to these sorts of chemicals, in drinking tap water. Refilling a plastic bottle with tap water will actually _reduce_ expose in comparison to buying a new bottle, where the water has been in contact with the plastic for a prolonged time. It’s maybe worth bearing in mind that the researchers doing the study have themselves switched to drinking tap water. If you are concerned, materials such as stainless steel or glass are a safer bet for storage. Aluminum is perhaps less wise. Whilst it is neurotoxic and a metalloestrogen only in _very high_ doses (which wouldn’t occur in water bottles; a greater source is your antiperspirant anyway), these are lined to prevent such leaching, and somewhat ironically, the epoxy to do this may be a source of BPA. Risk of microbial contaminants are relatively tiny. Tap water is chlorinated, and bacterial growth isn’t really a concern. In fact bottled water is no less sterile than tap water, and sometimes [worse](http://www.nrdc.org/water/drinking/bw/chap3.asp#figure8). No one collapses with cholera or typhoid from re-using a water bottle, unless they’re severely immunocompromised. In terms of relative risk of any of the above, they still fall statistically well short of other day to day issues concerning health, probably to the extent of tripping over said bottle, or impaling yourself on broken glass, should you decide to carry such an alternative around with you.