I believe they say a few years (3-5 based on climate). But on a survival board that I frequent, one of the guys said he had stuff in his garage for something like 12 or 15 years and used it and it worked fine.
22 posted on 12/22/2011 9:49:37 PM PST by Ghost of Philip Marlowe
(Prepare for survival. (Karl Denninger has jumped the shark. Do not visit his blog.))