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  #1  
Old 07-28-2005, 08:01 AM
deevee deevee is offline
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Difference Between Rubbing Alcohol and Methanol

The only thing I use rubbing alcohol for is to dab on the odd zit that pops up or to disinfect small cuts and scratches. The bottle is empty but I have a big jug of methyl hydrate in the basement. Is there any reason why I cant just use that instead?
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  #2  
Old 07-28-2005, 08:05 AM
CalMeacham CalMeacham is offline
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Rubbing alcohol is isopropyl diluted with water. It's got three carbons

"Methyl hydrate" (I swear I've never heard it called that, but Googling confirms it's a synonym) is methanol or methyl alcohol, with one carbon.

Completely different compounds. I wouldn't drink either one. I don't think rubbing methabnol on you is harmful, but check anyway.
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  #3  
Old 07-28-2005, 08:10 AM
xbuckeye xbuckeye is offline
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IANAD, but I handle methanol, ethanol, and isopropyl alcohol and there is no reason why it would hurt to use methanol over the others. Methanol is harder on fingernail polish than isopropyl alcohol.
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  #4  
Old 07-29-2005, 04:25 AM
scm1001 scm1001 is offline
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Interestingly the LD50 values for methanol (5.8 g/kg), ethanol (7.1 g/kg) and isopropanol ((5.8 g/ kg) (i.e the amount that will kill half of the test animals) are very similar. I suspect that methanol has more low level toxicity (i.e harmful effects).

However, methanol is classed as toxic and do not use on the body!
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Old 07-29-2005, 06:34 AM
xbuckeye xbuckeye is offline
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Quote:
Originally Posted by scm1001
Interestingly the LD50 values for methanol (5.8 g/kg), ethanol (7.1 g/kg) and isopropanol ((5.8 g/ kg) (i.e the amount that will kill half of the test animals) are very similar. I suspect that methanol has more low level toxicity (i.e harmful effects).

However, methanol is classed as toxic and do not use on the body!
LD50's only apply if you are drinking it. I don't think the OP is taking it internally or using it in culinary applications. I would recommend against taking any of them internally. I also wouldn't bathe in any of them. Intermittent small exposure, like the OP describes, has never caused anyone I have ever known any medical problems.
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  #6  
Old 07-29-2005, 09:24 AM
Enola Straight Enola Straight is offline
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IIRC, methanol can be absorbed directly through the skin.
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  #7  
Old 07-29-2005, 09:24 AM
Ruken Ruken is offline
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I'd stay away from methanol. At non-fatal doses it can still cause considerable nerve damage and blindness. Absorbtion through the skin can occur, although this isn't as fast as drinking it or breathing the fumes. Isopropanol still isn't good for you, but it's less volatile (less inhalation danger) and won't make you blind (I think).

You can search for "msds [alcohol name]" for many many links to safety information if anyone is interested.
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Old 07-29-2005, 12:02 PM
deevee deevee is offline
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Thanks folks. Although I will buy isopropynol on shopping day I think it's safe to dab my zit with a little methanol.
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  #9  
Old 07-29-2005, 12:07 PM
UncleBeer UncleBeer is offline
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Quote:
IIRC, methanol can be absorbed directly through the skin.
Correct. Here's the Material Safety Data Sheet (MSDS) for methanol.
http://avogadro.chem.iastate.edu/MSDS/methanol.htm
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