On Sat, 04 Jun 2005 04:05:59 +0100, David Peters
wrote:

On Fri 03 Jun 2005 23:16:22, The Natural Philosopher wrote:

Chris Lewis wrote:

According to Custos Custodum :

On Fri, 03 Jun 2005 13:59:36 +0100, Grunff
wrote:

David Peters wrote:

Why is isopropyl alcohol (propanol) reckoned by many people
to be a better general cleaner around the house than the
ethyl alcohol (ethanol) which is found in methylated spirits?


It isn't.


Ethanol has a lower toxicity. However, denatured ethanol
(meths) has pyridine added to it. Apart from being one of the
most vile smelling compounds, pyridine is relativly toxic.


It also rots rubber, which is why you should never use meths
for cleaning tape recorder pinch rollers.


Um, I think someone's confused. Methanol (which does eat
rubber) is _not_ denatured ethanol - it's methyl alcohol, aka
methyl hydrate aka CH3OH, aka "wood alcohol". Ethanol is
C2H5OH (aka ethyl alcohol).

Isopropyl alcohol is the next alcohol in the series: C3H7OH

The methanol/ethanol/propanol/butanol etc naming conventions
follow the same prefixes as methane/ethane/propane/butane etc.
(1, 2, 3 and 4 carbons).

Methanol is considerably more toxic than ethanol.

I don't know what the Grunff is referring to when he says
"meths". if he means methanol, he's wrong.

Methylated spirits is etahnol with enough mathoanol to make it
undrinkable exceptr by bums.

And Pyridine to make it obvious it's not bacardi.


I don't believe there is any methanol in UK "methylated spirits".
See the link in my footnote to my original posting which says:

"in the case of mineralised methylated spirits, with every 90
parts by volume of spirits there shall be mixed 9.5 parts by
volume of wood naphtha and 0.5 parts by volume of crude pyridine,
and to the resulting mixture there shall be added mineral naphtha
(petroleum oil) in the proportion 7.5 litres to every 2,000 litres
of the mixture".

http://www.opsi.gov.uk/si/si1987/Uks...n_5.htm#mdiv14

These are simply the additives for the different classes of methylated
spirits. What constitutes the basic 'spirits' is presumably defined
elsewhere.