[Alt-photo] Re: Food Grade Chemicals

[BOB KISS]

DEAR ERIC,
	Many moons have passed, Kimosabe, since my father worked for Merck
and Co...somewhere around the late 30s and then he was a pharmacist's mate
on ships in the Merchant Marines during WW II.  But he taught me at the very
beginning of my photographic endeavors (around 12 years old) that
Photographic Grade chemicals were well below Food Grade in purity and only
slightly better than Technical Grade.  Now this was half a century ago so I
don't know if either the grading system has changed or my memory serves me
properly.  The only time I would truly care about better than food grade
(Lab or Reagent grade) would be with very expensive metal salts (silver,
gold, platinum, palladium) and other reagents in their respective processes.
Other than that you should be fine. 
			CHEERS!
				BOB

-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org
[mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of
eric nelson
Sent: Thursday, July 11, 2013 7:26 AM
To: alt-photo-process-list at lists.altphotolist.org
Subject: [Alt-photo] Food Grade Chemicals

This is a cross post so sorry if you've getting it again.

I've *finally* found ONE chemical supplier here that has some of the
chemicals I need and use, but it turns out that they only supply "food
grade" chemicals.

Now this means that the prices can be cheap, which is good.  While talking
to them, I asked about their prices, which they don't list on their site. (
http://www.ucs1986.com/chemical.htm)  They asked me which chems I wanted,
so quickly scanning the list online I figured Sodium metabisulfite would
give me a good benchmark as to their prices.  1 kilo is 82 THB which equals
$2.63.

Score!

Umm, maybe!

So my question is, how usable are food grade chemicals in photography?  My
guess is that with something like a metal salt (not sure what that would be
doing in "food") in food grade might not be the best choice.  This subject
has been covered at length on this apug posting,  but goes on ad nauseum (
http://www.apug.org/forums/forum37/61248-food-grade-chemistry-ok-use-photogr
aphy.html)
and I'm hoping for a more concise discussion from personal experiences or
2nd hand experiences even. :)

e

-- 
Eric Nelson Photography
086 343 1612
http://ericnelsonphoto.tumblr.com/
https://www.facebook.com/EricNelsonPhotographyBangkok
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