Distilled Water

[PuffTheMagicDragon]

I have had the same gallon jug for a year or a little more and it seems fine. I keep it under the sink in the bathroom so it is dark and cool. No problems.

[CgarDan]

I pretty much had the idea that's how it works but helps when u get the same answer from a few people

[Stryprod]

The only plausible scenario is that minute amounts of petro byproducts from the plastic bottle could become introduced into the water especially when the bottle is heated up or has been in your cabinet for approx. 5 years. Hence why most people recommend replacing emergency water after a few years but obviously you will use all of it way before then so you are fine.