Developing Chemicals

I have some chemicals that are about 20 years old. Most of them are in powder form that need to be mixed with water. I can't find any expiration date on the packages. Do dry chemicals expire or loss quality with time?

My gut feeling is that they would be all right as long as the packages haven't been opened, have no stains on the outside and when opened the power seems consistently white. That said, your negatives are valuable and the cost of replacement chemicals relatively inexpensive that I personally wouldn't risk it. <p> If you want to give it a try you can test the fix with a leader from a roll of film. Soak an inch or two of the leader in water for a few minutes. Then to test the fix place it in the fix solution. Time how long it takes to completely clear. The clearing time should be approximately 1/2 half the recommended fixing time. This is also a good way to test fixer you have used previously. For example if it takes 4 minutes to clear then you fix for 8 minutes to be safe even if the <i>fresh</i> recommended fixing time is 5 minutes. Once the actual fixing time approaches twice the recommended time it is time to use fresh fixer. <p> As far as the developer you can use a test or unimportant roll you feel has been exposed properly and see how the negatives look. But again I would start from scratch with fresh chemicals. Hope this helps.

We've experimented with 55 year old powders at school and they work like the day they were made. As aleady mentioned, if the packages are intact and there is no obvious hardening or staining, there's a chance it may be fine. But you never know, so the risk is all yours.