While I know that the URAC expiration dates should be closely followed, I was under the impression that so long as the DAP remains dry, that it will last almost indefinitely. I have not had mine long enough to test that theory, but I bought a large container (5 lb) under that impression.
Russ
Not sure where I read that about the shelf life, RB. I would call the 800 number on the packaging to verify, though. I have also read that refrigeration may also help?