Kodak is notoriously conservative on storage life estimates. You can usually at least double their figures IME.
Originally Posted by brianmquinn
OTOH, as I said, mix up only enough to do the film you need to process, and dispose of the solutions. Storage life of working strength is, to me, a non-issue. Storage life of partially full opened concentrates IS, but doesn't seem to be a problem with E6. I kept the old Unicolor stuff long enough to use up an entire gallon, better part of a year best I remember, with no problems at all.