Do Fireworks Go Bad?

While at the house in Deltaville cleaning up and preparing for our party, I came across some fireworks that have been around for quite some time.  These particular explosives were a birthday present to one of my kids (seriously, why didn't I ever receive explosives as a gift??).  So the question was, do bottle rockets go bad?
I looked this up on the handy dandy internet and in short, no, there is no expiration date on fireworks.  However, there is a chance the humidity could make them a tad unstable.  So, we're going to get my dad the retired firefighter to set them off and see what happens.
Can't be worse than nearly blowing up a sailboat, or having a mortar fly straight for the audience, or have a firework fall and shoot inches from the truck hood.  I'm not admitting that happened before, just that those scenarios could be worse.

Bring on the explosives!