Marco B
Subscriber
Hi all,
Just stumbled upon these two Kodak documents I hadn't seen before. It is a list of recommendations and guidelines for disposal of chemistry.
- Environmental Guidelines for Amateur Photographers
- Disposal Guidelines for Discontinued KODAK Photographic Processing Products
May be useful to some, as I have seen many questions and threads about this particular topic. Whether everyone will agree with each and every specific guideline Kodak gives in these documents, is another matter...
Some inconsistencies I have seen:
- Why Chromium bleach is listed as "dis-chargeable to sewer", I personally have no clue... I guess it may actually be based on the non-chromium containing ferricyanide bleach, but that isn't consistent with the "Non-ferricyanide or chromium bleach" header in the table showing disposal options in the "Disposal guidelines" document.
- The "Environmental guidelines" lists Kodak acetic acid based indicator stop bath as non-dischargeable to sewer, unless neutralized using sodium bicarbonate because of a supposed very low 1.0 pH. Now that might be true for acetic acid stop bath concentrate, but I have never measured anything more than pH 4-5 in fresh working solutions, and in fact, the indicator function for spend stop bath is actually based on a slow neutralization process with carried over hydroxide anions from the alkaline developer bath. This means, by the time the indicator stop bath turns blue to indicate a spend stop bath, the pH is near neutral, and you can safely dispose of it down the drain... (assuming the small amount of carried over developer can also go down the drain)
Marco
Just stumbled upon these two Kodak documents I hadn't seen before. It is a list of recommendations and guidelines for disposal of chemistry.
- Environmental Guidelines for Amateur Photographers
- Disposal Guidelines for Discontinued KODAK Photographic Processing Products
May be useful to some, as I have seen many questions and threads about this particular topic. Whether everyone will agree with each and every specific guideline Kodak gives in these documents, is another matter...
Some inconsistencies I have seen:
- Why Chromium bleach is listed as "dis-chargeable to sewer", I personally have no clue... I guess it may actually be based on the non-chromium containing ferricyanide bleach, but that isn't consistent with the "Non-ferricyanide or chromium bleach" header in the table showing disposal options in the "Disposal guidelines" document.
- The "Environmental guidelines" lists Kodak acetic acid based indicator stop bath as non-dischargeable to sewer, unless neutralized using sodium bicarbonate because of a supposed very low 1.0 pH. Now that might be true for acetic acid stop bath concentrate, but I have never measured anything more than pH 4-5 in fresh working solutions, and in fact, the indicator function for spend stop bath is actually based on a slow neutralization process with carried over hydroxide anions from the alkaline developer bath. This means, by the time the indicator stop bath turns blue to indicate a spend stop bath, the pH is near neutral, and you can safely dispose of it down the drain... (assuming the small amount of carried over developer can also go down the drain)
Marco
Last edited by a moderator: