Dave Smith wrote:
>
> They are more concerned with food grade propane ?
>
> :-)

No, that's psychiatric issue. People who deny
the existence of food grade propane have issues
that need professional help. ;-)



Steve Wertz wrote:
>
> I think somebody was maybe confusing food grade gases such as CO2
> or N2O and figured there must be a food grade version of
> propane/butane, too...
>
> But instead of simply admitting his mistake, went to unnecessary
> lengths to try and cover it up.

Dave Smith wrote:
>
> WTF ?????
> Where the hell did you come up with this food grade propane stuff?

George wrote:
>
> Don't think there is such a thing. I think both propane
> and nat gas must include an odorant (usually methyl mercaptan).


This belief is refuted by several patents to food chemists
at Cargill, such as U.S. Patent 6,610,343:

http://patft.uspto.gov/netacgi/nph-P...S=PN/6,610,343

"Most preferably, the solvent is a category I solvent
approved by The Council of the European Committees
(Jun. 13, 1988 Council Directive) for use in food
processing. Food grade propanes and butanes generally
meet all of the above stated preferences."

And it is further refuted by a study made by a
scientist at the USDA:
http://www.ars.usda.gov/research/pub..._NO_115=121505

"A new commercial invention incorporating a supercritical,
low-pressure, liquified gas extraction process using
food-grade butane as the extraction gas is currently
being used to extract chocolate liquor and peanuts and
the oil and residue solids are both edible products."

And just for fun, here's one from the
Propane Education & Research Council (PERC):
http://www.propanecouncil.org/files/
11352_EEA_GoodPractices_Report_Final.PDF

"The requirement to add odorant can be waived in
special-use applications, such as aerosol propellants
and food and drug products where the odorant has a
detrimental effect on the final product."


Here's what PetroCanada said to a guy inquiring
about accumulation of impurities in propane-
powered vehicles. It sounds like pretty nasty
stuff for use directly on food.

Quoting from:
http://cars.rasoenterprises.com/Propane-Residuals.htm

"Most propane as it is produced at a gas plant
(the majority of product in Western Canada) or
refineries is very clean. However, during
distribution it can pick up contaminants such
as traces of gasoline or diesel fuel (if pipelined
through a common products pipe line, or in storage
caverns) or extract some plasticizers from hoses
and gaskets. Some of these contaminants,
particularly diesel fuel and lube oil range
materials, have low volatility - so as propane
is evaporated in a converter (changing from a
liquid to a gas), the contaminants remain behind
at a low point in the system - which can be the
bottom of the converter, or a low-lying loop
in a fuel pipe delivering propane vapours to
the carburetor. So there is no 'conversion' or
'breakdown' of propane into oily residues in
a converter - the residues are contaminants
left behind when the propane evaporates.
Unfortunately, the current propane specification
allows rather a lot of oily residues - up to
500 ppm. I've seen instances of 6 - 12 ppm
oily contaminants (6 - 12 litres of oil from a
million litres of propane used in a high volume
heating situation) being enough to cause problems
with build-up of the oil in the bottom of large
converters."

"While instances of contaminants in propane have
been on-going for decades, and appear in different
forms (oily materials, 'grease-like', 'black
shoe-polish', and waxy deposits), they are usually
sporadic, even seasonal, and we (the industry)
have not been successful in finding the sources
of all the contaminants. It is clear that potential
future uses of propane, such as fuel cells, will
require very clean product, and current
contaminants will be totally unacceptable."