shelf life of raw photographic chemicalsgreenspun.com : LUSENET : B&W Photo - Printing & Finishing : One Thread
The thought dawned on me today after going through some of my raw, unmixed chemicals; what is the shelf life of these chemicals. Fixer components, paper developer components, ferri, etc.. The chemicals are kept sealed and in dark, cool conditions. Do they begin to lose any of their original potency or begin to break down? If their is a published source for this information, I would appreciate it if anyone could point me in the right direction. Thanks.
-- brian jefferis (email@example.com), May 29, 2000
I think this was mentioned in the last or next to last issue of Photo Techniques magazine. Most raw chemicals have infinite shelf life if properly stored, with some exceptions, usually developers. I know Glycin stores poorly in raw form, and Pyro will darken with age. Phenodone (sp?) also has a limited life, though I have some that's getting rather elderly and still seems OK.
-- Conrad Hoffman (firstname.lastname@example.org), May 29, 2000.
The ionic compounds ie sodium thiosulphate (hypo), sodium carbonate, pot ferricyanide, etc etc are stable in sealed containers. If they are in loosely sealed containers they might oxidise, evaporate, or absorb/loose water. Most organics compounds are also stable and much the same applies. Always best to keep chemistry in dark place.
I agree with Conrad.
-- david strachan (email@example.com), May 30, 2000.