Can plastic leak into water from a HDPE "2" plastic container at room temperature?

Here in USA supermarkets often sell water in plastic 1 gallon jugs. These jugs seem to all be stamped with the text "HDPE" (meaning that the material is High-density polyethylene) and a resin number of "2" on the bottom.


I had one of these jugs, containing distilled water, on a counter in the kitchen, and another one in the refrigerator. For some reason the water on the counter had a light plastic taste, whilst the water in the fridge did not.


Could this taste be because of plastic leaking into the water? Or what else could cause the plastic taste?




HDPE 
has a molecular weight more than several hundreds of thousands, 
"leaking" is plainly impossible. 
This taste is the tase of stale water, nobody knows 
what that taste is actually. 
Maybe its just the taste of not cold enough water,
lacking some dissolved air, or some bacteriae 
develop after contact with air and light. 
(google for pseudomonas) 
The only substance which ever got into the jug prior 
to the water is the air (or some other gas?) used to  

inflate the jug in production. 
But that cause would impair the taste of the water in 
the fridge as well.


BTW why do You drink such botteled water? 
What about the tap water in your town/city/village? 


 7

This should've been a comment as it only backs up Georg's answer, but it just got too long for that.


Plastic doesn't "leak", scientifically. However, it can go through [the degradation process](http://en.wikipedia.org/wiki/Polymer_degradation).


You don't provide enough info for anyone to decide, but if you're certain that *was* the "plastic" taste (I don't have much idea how you do) it's possible it may have gone through degradation, though I can tell you 95 percent of the time it isn't. And that's simply because if the plastics were too unstable to resist minor chemical or energetic "attacks" (read the wikipedia article for degradation to see what I mean), they wouldn't have produced it like that.


There is the urban hoax that doing stuff like pressurizing a mineral-water bottle by freezing the water inside releases dioxins that are carcinogenic and which cause the change of the taste of water, but this, is **not** true. (See [here](http://cancer.about.com/od/cancercausesfaq/f/freezingwaterbo.htm).)


Georg's answer pretty much sums it up, but I think it's better to add: It may also be possible that you (or anyone else, or mistakenly the company itself) put the "tasty" water in contact with soluble mineral salts. Thus, you drink [hard water](http://en.wikipedia.org/wiki/Hard_water) and swear for its taste!


 3

I agree with the other answers, it is definitely not HDPE, however, it could be one of the chemicals known as plasticizers that are used in the process. There is always leftover plasticizer in the bottle and these are known to leach into water. 


The NIH sponsored multiple studies on the levels of this, one of them published here:


<http://www.ncbi.nlm.nih.gov/pubmed/21400322>


 2