I was trying to remove some sticky label gunk from a Plexiglass label holder with isopropyl once. As the alcohol dried, the box was instantly spiderwebbed with cracks throughout its structure. Somehow the alcohol caused it to just come apart.
Plastics are a different beast-much more sensitive to solvents.
Hmmm. I just took a look at the MSDS for isopropanol. It seems that you actually could consume a small amount of it without experiencing instantaneous catastrophic global organ failure (not that I’m inclined to try it, mind you).
So if I were a 90 kg. mouse, the LD50 would be 324 grams, or 413 ml.! Hell, I’ve drunk the equivalent amount of ethanol and wished I were dead the next day. I really could see a diehard alky trying to get drunk on the stuff.
That’s not the end of the story. Aldehydes are typically pretty unstable in that they’ll oxidize pretty quickly. That is, acetaldehyde will become acetic acid, or relatively harmless vinegar, while the formaldehyde (embalming agent) will be oxidized to formic acid (the poison used by some ants).
That’s not the end of the story either (ie how do those acids react with tissue on a molecular level and render you blind?), but it should put the result of consuming those substances into a more identifiable context.
Anyway, this is the structure of isopropanol:
CH3-CH-CH3
|
OH
Assuming that the enzymes that work their magic on ethanol and methanol can do the same for isopropanol (I’m not sure what difference it would make to have the -OH group in the middle of the carbon chain rather than at the end), there’s only one product from the oxidation of that compound:
CH3-C-CH3
||
O
This is acetone. One doesn’t drink acetone.
Protected coatings on glasses. 
Yeah - but it’s a rare thing. That was one guy out of thousands of people with drug/alcohol problems we’d seen in the years I was there.
Perhaps. I really don’t know that much about his medical/drinking history. I do know that he had entirely given up on ethanol years before. I don’t know if he’d refuse it if he couldn’t get isopropyl (given that iso is laughly easy to come by and so much cheaper than ethanol) but rubbing alcohol was clearly his poison of choice.
IPA also damages rubber. You can use it to clean mouse-balls, VCR belts, etc., but they have to be in pretty good condition to begin with and you need to dry it off ASAP. I learned the hard way not to use it on a dried up old tape roller.
I’ve also heard that IPA can dissolve the fibers in some synthetic carpets.
As far as IPA and Rubbing Alcohol on tape heads: The former is okay to great depending on concentration (at least 90%, 99% best), the latter is a big no-no.
If I recall correctly, most of my tape players recommended isopropyl alcohol for cleaning the heads, but specifically said not to us “rubbing” alcohol, which is what was commonly available in grocery stores or department stores. For Isopropyl alcohol you usually had to go to a pharmacy, or a parts store like Radio Shack, or an audio equipment store.
The difference was that rubbing alcohol wasn’t pure (as you said) and usually contained some oils that were beneficial for skin, but left a residue on the tape heads. Pure isopropyl alcohol just evaporated away to basically nothing left.
On preview, I also agree with ftg in that while you could clean the heads with alcohol, you were always warned not to clean any pinch rollers or other rubber parts. Over time they really damaged the rubber, making it “dry” and inflexible.
I am not quite sure what youare trying to say. Acetone is pretty harmless and its LD50 (oral rat) is even slightly less toxic than isopropanol (acetone ORL-RAT LD50: 5800 mg/kg)
Are you thinking of vinyl records? Apparently the vinyl used for LPs is formulated with “plasticizers” that make the surface more resilient. Cleaning the record with isopropyl alcohol is said to dissolve the plasticizers, leaving the surface more vulnerable to wear from the pressure of the stylus.