A Science Question

[Doug_Tipple]

I recently had reason to look around in my hall closet, and I discovered that all three of my gallon plastic jugs of water had developed small leaks and were making a big mess. I had water-soaked Kleenex, toilet paper, and other cardboard boxes that were beginning to mold. The water had been in the closet for a couple of years, left over from when I used distilled water for a cool-mist humidifier. My only use for distilled water currently is for my steam iron, and I am not doing much ironing these days. After cleaning up the mess I started wondering what had made the water bottles start to leak, since they had never been opened. What are your thoughts on why the bottles developed leaks?

[dwest]

What type of plastic? I'd take them back, surely you still have the receipt in your tax files? I would.

[emmline]

Where were the leaks? Around the caps? In seams?

[crookedtune]

This worries me. Weren't the boundless landfills of plastic to be our legacy for all eternity?

[Doug_Tipple]

Where were the leaks? Around the caps? In seams?

The leaks were near the bottom of the jugs, not in seams.
The jugs are marked triangle 2, HDPE, high-density polyethylene, I believe

[Doug_Tipple]

Update: of the three votes thus far, one person has the correct answer, if there is such a thing. With all of the blurring of reality in the media these days, I'm beginning to wonder if truth even exists.

[Denny]

closet monsters

they're a big problem in the mid-west

the little ones are hard to catch

[s1m0n]

Distilled water contains only H20 molecules, so it has lost its ions, because these require the presence of other molecules in solution (usually in the form of salts, iirc) with water.

Water really likes to have ions around, and it likes them so much that it can break the ion bonds in other material and take over what it wants. One such material is plastic. Distilled water will corrode plastic like an acid* over time. For long term storage, you need to keep it in glass, not plastic.

*which it is, actually, in that distilled water has very low ph.

~~

Incidentally, this is also why it's a bad idea to drink distilled water. Once in your system, DW will pull salt ions through the walls of other cells. Enough of that will destroy the cells.

[dwest]

Water is the universal solvent after all. But nightmares live in closets, like any living organism they need water but I doubt they understand bottle caps. I use distilled water for my vehicle's' radiators and batteries, my insects and fish. We use chloramines for drinking water here, the fishys and the buggys don't like it.

[Innocent Bystander]

Explains a lot, dwest, we use water for drinking water.

[dwest]

Explains a lot, dwest, we use water for drinking water.

Funny thing, we use it the same way here, however when it comes to distillation we prefer certain distilled products from Scotland and Poland, we don't drink distilled water.

[Doug_Tipple]

No sense being in a big hurry, my mother used to tell me. Anyway, I will end this science quiz early. Six people voted on the quiz: (1) plastic eating parasites, (3) defective containers, (1) barametric fluctuations, (1) planned obsolescence. Simon may also be correct in his analysis, but my answer is "barametric fluctuations". I think that one could also argue that (defective containers) is also a correct answer, as the manufacturer certainly knew about the limitations of the containers over a period of several years. Not many people are going to be too concerned about leaking water, though.

Thin-walled plastic containers that are sealed will flex as the ambient atmosphere pressure changes. Polyethylene will easily flex with the changes, but over time this continual flexing will cause failure of the material, often at the edges of folds or creases caused by the flexing. An extreme example of the effect of atmospheric pressure can be easily seen if you drive in mountainous areas. I used to hike near the top of a mountain near Tucson, Arizona. I would close my plastic drinking bottle on top of the mountain (9,000 ft. elevation), get in my car and drive down the mountain to the valley floor (3,000 ft. elevation). I often found myself startled to find that my nearly empty drinking bottles had become totally crushed by the higher atmospheric pressure of the lower elevation.

The above example is a good reason that flammable liquids or other hazardous materials need to be kept in containers that have been especially designed for this use.

[Denny]

and not kept in closets that are in elevators

[dwest]

We don't care to buy bottled water but we keep a supply in our pantry as we are in an area that can suffer prolonged(weeks) power outages and compromised water supplies. We replace it every fall so this thread was a timely reminder.

[emmline]

I used to hike near the top of a mountain near Tucson, Arizona. I would close my plastic drinking bottle on top of the mountain (9,000 ft. elevation), get in my car and drive down the mountain to the valley floor (3,000 ft. elevation). I often found myself startled to find that my nearly empty drinking bottles had become totally crushed by the higher atmospheric pressure of the lower elevation.

Another example is how when I got off the airplane on Sunday, and opened my Sigg bottle to have a drink, it spewed at me.