Flare replacement

I have a shrink wrapped Orion flare and distress kit with an October 2007 
expiration date.  Is there any reason I can't just open it up and replace 
the pyrotechnics?  Surely the whistles, signal mirrror, etc. are going to
be 
just as good a decade or so from now as they are today.

I would keep the old flares in an appropriate container "just in case".  I

know someone who blew a finger off shooting off an expired flare New Years

Eve but it was very old.  I wouldn't keep the expired ones more than a
date 
cycle.

-- 
Roger Long