[Alt-photo] Re: Food Grade Chemicals

[sam wang]

The ferric ammonium citrate I received many years ago for cyanotype was food grade. I think as long as you can find it, food grade or not makes no difference.

For many years casein was mainly available commercially as a food source, and smallest quantity you could buy was 50 lbs, at about $1/lb.

Sam

On Jul 11, 2013, at 7:26 AM, eric nelson <emanphoto at gmail.com> wrote:

> 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-photography.html)
> and I'm hoping for a more concise discussion from personal experiences or
> 2nd hand experiences even. :)
> 
> e
> 
> -- 
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