Methanol? (WHY?)

[Tim Keenan & Rebecca Counts]

Also sprach JIMRPT:

JIM>  Alcohol in any form if abused is toxic, and so is milk, butter, 
vitamin A, B,
> C, etc., etc.  Common sense needs to be used when applying any liquid in an
.....

Now, hold on thar, pardner-- I have no wish to get into a fractious 
debate, here, but it is clearly disingenuous to compare the toxicity of 
organic solvents to that of common foodstuffs.

Vitamin A is indeed toxic in reasonably small quantities, but you are 
not likely to be exposed to them except if you eat large quantities of 
shark liver. It is fatuous to talk about "toxicity" in the same breath 
with milk and butter (or vitamin C for that matter). Toxicity is a direct 
interference in a metabolic process. It was not my intention to be 
alarmist, but most people are entirely unaware that methanol is readily 
transported into the blood via the skin and lungs.  The Merck Index reads 
"poisoning may occur from ingestion, inhalation, or percutaneous 
absorption. Death from ingestion of as little as 30 ml has been reported 
"(thats 2 tablespoons to Americans).  Chronic poisoning leads to visual 
impairment.

Just for the list's information, from the US Federal Register, Volume 36, 
Number 105 (as quoted in the CRC Handbook of Chemistry and Physics) the 
limits for exposure in air for a few common solvents (parts per million):

Ethanol			1000
Acetone			1000
Gasoline		500	(Hexane, Heptane, Octane)
Methylene Chloride	500
2-butanone 
 (Methyl ethyl Ketone)
 (lacquer thinners)	200
Methanol		200
Toluene			
 (contact cement solv)	200
Naptha			100
Turpentine		100

The thing about methanol is that it is an extremely small molecule--only 
1 Carbon atom with 3 hydrogens and oxygen attached to another hydrogen.  
Because of this, its absorption thru skin is very rapid.  

I certainly never suggested not using it, but just that one should be 
aware of these things.  Certainly if denatured alcohol (which is ethanol 
with a small proportion of poisons such as methanol, benzene, 
aniline, methyl violet added to it so that anyone foolish enough to drink 
it will get his protestant just desserts) is as effective for the 
purpose, it would be a better choice. The LD50 (lethal dose for 50% of 
subjects)  for ethanol (in rats, of course, not people) is 13.7 g/kg.  
That means that someone like me would have to take 1.27 kg of absolute 
ethanol to kill me.  That would be a several quarts of 80 proof liquor.  
That is a lot more than 2 tablespoons.

JIM>We should not be using any liquid that is volital in an
> enclosed - non ventilated space period....this includes fingernail polish and
> fingernaill polish remover (laquer thinner w/oils) both of which are highly
> toxic at the same levels as methanol.

Not exactly.  Nail polish/removers contain acetone and/or butanone, which 
 are somewhat less toxic than methanol (acetone is 1/5 as toxic in air).

JIM>  Can anyone think of anything more toxic
> than lye? Lye is an important component of most of the commercially available
> soaps of all descriptions.

Lye (sodium hydroxide) is not "toxic" in any normal sense of the word--it 
is caustic, and will directly damage tissues *as lye*, but in soap is is 
used in the saponification process to change fats into soap.  It becomes 
part of the chemical structure of the soap, and is not present as 
hydroxide at all.  Some of the most toxic chemicals known to humanity are 
used in the manufacture of vinyl (polyvinyl chloride, polyvinyl acetate), 
but vinyl plastics per se are not toxic.

JIM> Gasoline is much more toxic than Methanol and you breath those 
vapors on an
> everyday basis.

No.  Gasoline (in air) has a limit 2.5x greater for human exposure, and, 
as I mentioned, because the molecule is 6 to 12 times larger, it is not 
as readily absorbed through the skin.  And I make every effort not to 
breathe gasoline vapours, which are much more obvious to the nose than 
methanol vapours.

JIM> OK. If you spill any on yourself use that toxic lye, to wash off the 
toxic
> alcohol, with plenty of  water ladened with that toxic chlorine, along with
> the toxic oxygen and the toxic hydrogen.
> 
> Methanol highly toxic? of course........but so is milk... just use common
> sense folk.
> Just another view.
> Jim Bryant (FL)

Why do they call it "Common Sense"? It ain't all that common, or all that 
sensible.

Tim "sayin' so don't make it so" Keenan
H.B.Sc., M.Sc.
Noteworthy Piano Service
Terrace, BC.