I found some older Ilford fRapid Fixxer recently (liquid). How old, I have no idea, but there was a lot of it so I thought I would give it a go. I am too cautious to use it for film, but I thought for paper, what the hell, why not? How would I test to make sure it is doing what it should? I use an Edwal product to test fixer, the stuff where you put a few drops in the fixer and if you get a precipitate, the fixer is no good. But that probably wouldn't work with a new (even if outdated) fixer.
Any thoughts on this? If it is any help, there was no dust in the container, so I am figuring no more than a few years old.