overheated hand sanitizer

[WM]

I left a small plastic bottle of hand sanitizer in my car the other day. The bottle was inside another bag, so it wasn't in the direct sunlight but it was about 85 degrees and sunny all day. When I retrieved it, the bottle was expanded as though it had been at altitude, and the plastic seemed stiffer. The gel itself seemed ok. What's the deal? Is it dangerous to leave this stuff out in the heat?

 

[Ed_The_Gypsy]

I expect that the alcohol in it came out of solution when the temperature went up. The vapor pressure increased A LOT! A full bottle might pop open and make a mess. The alcohol is flammable and may be dangerous to breath. Keep the bottles small and in a zip-lock bag just in case. I wouldn't leave it out in the heat.

 

[REattempt]

The bottle expanded because alcohol (primary ingredient) has a high vapor pressure (and concequently a low boiling point). Alchohol is known as a volatile solvent because it evaporates easily. The bottle expanding was simply the alchohol boiling off.

There really isn't any "problem" except if there is anyway for the gas (and liquid) to escape, it will leak out. As long as there is no source of ignition, leaving it in the heat isn't really a problem.


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[braumeister]

Keep the bottles small and in a zip-lock bag

See?
Maybe next time you'll listen to your friendly TSA agent.

 

[Nords]

Would heating a bottle of sanitizer kill off its bacteria or encourage faster growth?

I hope that's a trick question...

 

[Texas Proud]

Live in Texas where the temp inside a car gets to 140 degrees pretty fast if left in the sun.... never had a problem with our sanitizer bottle...

 

[Telly]

Live in Texas where the temp inside a car gets to 140 degrees pretty fast if left in the sun.... never had a problem with our sanitizer bottle...

Yep, she blew up long before we got to the car!

 

[WM]

Interesting - thanks. It was a small bottle, but mostly full. So what you'd actually want is a large bottle that's mostly empty - not much alcohol to boil off, and more room for it to expand, right? When I saw it, I was happy it hadn't oozed everywhere. From the look of the bottle, there was a lot of pressure built up!

 

[braumeister]

One other thought:
I'm guessing that when you loosened the cap to relieve the pressure, some of that vaporized alcohol was released into the atmosphere. Do that several times and the level of alcohol remaining in the sanitizer might be low enough to render it much less effective at its sanitizing job.

 

[LOL!]

If the alcohol boiled off, then the bottle would not have expanded since "boil off" implies the alcohol escaped. Perhaps the word to use is "vaporized".

Now suppose you had this in the sunlight in your car such that the light was focused on the gel such as can occur with a magnifying glass or some mirrors. Would this thing explode and strew flaming napalm all over the inside of your car? I suggest you try the experiment.

An overseas colleague left a 12-pack of soda in his rental car last weekend. Eight of the 12 cans popped and disgorged their contents.

 

[LightningDawg]

I have several partially used bottles in my car....and it gets well over 100 degrees inside during the day. No problems with any of them.

 

[WM]

One other thought:
I'm guessing that when you loosened the cap to relieve the pressure, some of that vaporized alcohol was released into the atmosphere. Do that several times and the level of alcohol remaining in the sanitizer might be low enough to render it much less effective at its sanitizing job.

I wondered about this, but when I opened the bottle (at room temperature) it didn't seem to release any pressure. Certainly the bottle didn't go back to its normal shape. Assuming it was a closed system, did the vaporized alcohol re-liquefy as it cooled and mix back in? I can't tell any difference in the gel, it's not like it dried up or anything.