Xane T. wrote:
On 15 Dec 2004 13:12:17 -0500, (Roy Smith) wrote:

Denatured Alcohol is absolute ethanol with a little methanol added
to
it, to intentionally make it unfit to drink. Since you can't drink
it, the government isn't interested in taxing or controlling it, and
it's much more widely available than absolute. For most uses as an
industrial solvent (such as for disolving shelac), the little bit of
methanol doesn't really matter. If memory serves, the addition of
the
methanol also aids in the removal of the last bits of water during
the
distilation process.

It's not always methanol. The bottle of Ace brand denatured alcohol
is
denatured with both methanol and MEK, it's more poisonous than it
needs to be. I think the Kleen Strip brand is the one that has only
methanol to denature it.

ISTR that the brand with "SLX" on the label was denatured with methanol

only. I avoid anything with ketones because they are quite toxic as
well as more noisome. At one time sulphuric acid was used as a
denaturant. I remember an episode of "Untouchables" with Robert
Stack as Eliot Ness in which the villian was a chemist who had found
a way to 'renature' denatured alcohol. Assuming there was _some_
historical basis for that episode this may have been a referance
to using sulphuric acid as a denaturant.


What's sold in most drugstores as "rubbing alcohol" is isopropanol
(typically 70%, the rest is water). To the best of my knowlege,
it's
not toxic, at least in small quantities. The reason it's sold in
drug
stores is because it evaporates fast, so it makes a great cooling
rubdown.


All alcohols are toxic. Ethanol is just the least toxic, well maybe
some of the fancy alcohols used in mouthwash might be less toxic than
ethanol but I doubt it. Isopropynol is plenty toxic, you just do not
absorb enough through occaisional exposure to unbroken skin to be a
concern. I _think_ methanol is better absorbed through the skin, but
is less toxic when ethanol is also present, oddly enough.

In fact I'm pretty sure that all organic solvents and almost all
organic liquids, excepting some oils, are toxic. Certainly all
the common ones are *quite* toxic.

... Ethyl alcohol is also sold as 'rubbing alcohol', which I believe
is also a form of denatured ethanol. The label I read at CVS last
night had all sorts of odd ingredients in it other than ethyl
alcohol,
in fact it looked /more/ poisonous than woodworking denatured stuff.

Quite often the ethyl alcohol (aka ethanol, aka grain alcohol) sold
for rubbing alcohol is denatured with methanol just like the denatured
alcohol sold for shellac thinner. The other stuff on the label may
well have been added to enhance it's effect when used for, well,
rubbing, or whatever you're supposed to do with it.

--

FF