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The environmental risk is from unexposed silver halide that you rinse off the film in the fixing step. The developer isn't really the harmful chemical; though

The environmental risk is from unexposed silver halide that you rinse off the film in the fixing step. The developer isn't really the harmful chemical; though do read the MSDS for the developer you use and follow its instructions. (I wouldn't want to absorb it through my skin, breathe too much of the vapor, drink it, etc. True of the chemicals I use to clean my bathroom, too. Risk can be mitigated through proper safety measures!) People reuse fixer, or at least I do, but there is a point where it's exhausted and needs to be discarded. My understanding is that the environmental risk from hobbyist developing is exceedingly low and dispose of it accordingly. If I were deeply concerned, I'd just let the liquid evaporate and store the solids in a plastic bag in a drawer. (That seems to be the NileRed approach to metal waste. When you're tired of the bag, you pay for professional service to take it away.)

totetsu 5y ago
if fix is supposed to keep the paper from discoloring over time, which is not immediately aparent, how do you know when your fix needs to be replaced?
- jrockway 5y ago
  I am not sure about discoloration -- I don't develop paper very often, and I don't use fixer for any reason other than to remove unexposed silver halide. (Without a fixing step, you could expose the film to light and run it through the developer again, and have another image. Or most likely, just completely ruin the negative. Fixers claim to do a lot of things, but washing away silver halide is the reason it's a mandatory step.) For measuring exhaustion, I look at the datasheet to estimate the area of film that it can fix before exhaustion, and keep track with tick marks on my bottle. I typically use Ilford Rapid Fixer diluted 1+9 (100mL fixer -> 1L of working solution). 5L of fixer develops 2000 8x10 sheets, so 100mL does 40 sheets. I mostly shoot 4x5, so that's 160 sheets. When there are 160 tick marks on the bottle, I discard it and make a new batch. (Honestly, expiration dates are really my limiting factor. 6 months in a tightly capped bottle.) Film photography is 99.9% bookkeeping and 0.1% art ;)
  - totetsu 5y ago
    I have recently been using my room as a pinhole camera. I have wasted so much paper and money to also come to that conclusion. Next on my to buy list is that Ilford darkroom paper light meter. But it's hard to take notes in the dark.
JKCalhoun 5y ago
I have been dropping steel wool into the developer and letting it sit for a day or so. I had read about this in a few forums — I assume the iron reacts in some way with the developer to create a chemical less toxic.

totetsu 5y ago

if fix is supposed to keep the paper from discoloring over time, which is not immediately aparent, how do you know when your fix needs to be replaced?

jrockway 5y ago
I am not sure about discoloration -- I don't develop paper very often, and I don't use fixer for any reason other than to remove unexposed silver halide. (Without a fixing step, you could expose the film to light and run it through the developer again, and have another image. Or most likely, just completely ruin the negative. Fixers claim to do a lot of things, but washing away silver halide is the reason it's a mandatory step.) For measuring exhaustion, I look at the datasheet to estimate the area of film that it can fix before exhaustion, and keep track with tick marks on my bottle. I typically use Ilford Rapid Fixer diluted 1+9 (100mL fixer -> 1L of working solution). 5L of fixer develops 2000 8x10 sheets, so 100mL does 40 sheets. I mostly shoot 4x5, so that's 160 sheets. When there are 160 tick marks on the bottle, I discard it and make a new batch. (Honestly, expiration dates are really my limiting factor. 6 months in a tightly capped bottle.) Film photography is 99.9% bookkeeping and 0.1% art ;)
- totetsu 5y ago
  I have recently been using my room as a pinhole camera. I have wasted so much paper and money to also come to that conclusion. Next on my to buy list is that Ilford darkroom paper light meter. But it's hard to take notes in the dark.

JKCalhoun 5y ago

I have been dropping steel wool into the developer and letting it sit for a day or so. I had read about this in a few forums — I assume the iron reacts in some way with the developer to create a chemical less toxic.