possible chemical contamination problem question

[brian steinberger]

Tonight I mixed up a new 1 gallon of rapid fixer. I had just finished off a chemical bottom that was filled with D-76. I emptied the bottle of D-76 but did not wash it out. While I was mixing the new fixer there were two one-gallon bottles sitting beside each other, the one of the old D-76, and the one that was waiting for the new fix. Well after mixed the fixer, I poured 1/2 gallon into a tank, cause I was getting ready to develop, and then I grabbed the wrong bottle and started to pour the other half gallon in the D-76 container!! OOPS!! So, I continued to process until I was done, and now what I have is, 1/2 gallon of nice clean fixer, and another 1/2 gallon of fixer that was temporarily dumped into a bottle that had previously been used for D-76 but hadn't been washed. I haven't mixed the two yet. Am I safe to use this haf gallon? Or should I just pitch it and work with the good half gallon that I have left? Sorry, this is a stupid long explaination, but I'm just an idiot.

[Kevin Crisp]

Brian: As a 16 year old, I realized that I could skip that silly stop-bath step since rapid fixer would stop development and clear the film too. Now I know better. But it worked just fine and the negatives still look good 35 years later. (The same isn't always true of the general fixer I used, skipping the stop bath step, the paper sometimes didn't hold up so well.) I'd put the slightly contaminated rapid fixer in with the fresh and use as per usual.

[John Berry ( Roadkill )]

Not to worry, It's the same end as if it never happened. The worst view is that the fixer has been used to develop one roll so far.

[Ed Pierce]

I would chuck it. It's not worth the risk. Your negatives are priceless and irreplaceable; a new gallon of fix costs five bucks.

[Erik Gould]

Chuck it? No, I wouldn't. Fixer is easily tested. Just take some scrap film and check if it clears. Make note the clearing time. Double that and there's your fix time. Pretty simple. I would only discard it if it didn't clear the film in a normal amount of time. I'd bet your fix is just fine.

[Donald Qualls]

A tiny bit of developer in the fixer (can't be as much as an ounce in your gallon of fixer, if you dumped the D-76 out of the jug at all carefully) won't hurt anything. There are all kinds of warning about dichroic fog if you have active developer in the fix, but that can't happen unless your fix is alkaline or you're using an amidol or ferrous sulfate developer. Given that your fix is acidic, it's nothing to worry about. It's also a bad idea to leave developer on negatives over a long term, but it'll wash out at least as rapidly as the fix does, so if you're washing adequately to begin with, the developer won't cause trouble there, either.

Going the other way is a significant problem only if you get enough (acid) fixer in the developer to change the pH and thus reduce the developer activity, or if you get enough (neutral to alkaline) thiosulfate into the developer to cause significant solvent activity, which can cause dichroic fog -- and not always even then. I've made and used monobaths on occasion, which are nothing more than developer and fixer mixed together and the pH corrected to a level that lets the developer work before the fixer finishes...