From: Sil Horwitz (silh@earthlink.net)
Date: 06/16/03-04:50:53 PM Z
-------Original Message-------
From: Richard Urmonas <rurmonas@senet.com.au>
Sent: 06/16/03 05:38 PM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: a question about chemistry and septic tanks
>
> On 2003.06.17 03:10 Devra Goldberg wrote:
> to clarify, what i should say is that i'm not actually
> _dumping_ anything, save, of course, for the tmax.
> the question i really am asking is, is it safe to
> process a cyanotype or a gum print and them dump the
> water?
>
> and if no, how does one contain the cyanotype water
> while processing--since it's running water, as opposed
> to still water for gum?
Gum print water has dichromate in it. This is nasty stuff
and really should be disposed of as chemical waste.
Cyanotype is one of the least toxic photo processes, someone
else may be able to comment on safety in dumping it. If I was
dumping it I would probably spread it around the garden, rather
than down a septic tank. All silver processes are bad, so
any waste from a silver based process should be handled appropriately.
>From Sil --
If we were talking about kilograms of these "toxic" chems, then I would have to agree with what has been said about disposal. But we are not: we are using very small quantities. As I presented in great detail in my talk at the 2nd APIS, most of the materials we use in the quantities we use are not hazardous. There are micrograms of chrome compounds, for example, in most environments. To be specific: all developers break down in both sewage and septic tank environments, so are not a problem. Fixer also breaks down, but the silver content is critical: a few micrograms of silver waste will not corrupt systems, but if you are commercial and dispose of gallons/multiliters of the stuff daily, you will have to make disposal arrangements unless you precipitate the silver, after which the fixer is non-toxic to sewage systems. If you do use large quantities, then the Kodak pamphlet on proper disposal is the authority. In addition, Kodak (and probably others) have disposal instructions (mainly for commercial quantities) on their website. Be cautious, not hysterical.
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