How old is too old?
 

We were given some powder when a friend of the family passed. As you can see some of the powder must be older to be in those metal cans and the three pound container. Any idea how old this is and whether or not it would still be usable?

Open the can and check by smell; the typical but slight ether/alcohol solvent odor indicates the powder is likely still good. On the other hand a sharp acidy smell is an indication of powder that's deteriorating. Bad news.

Here's a old paper 15lb canister of Red Dot that still has about 5lbs left. It smells good and shoots good.

I got a 12 pound metal keg of Red Dot a couple years ago with the provision that I could load some with it and shoot them to make sure the stuff functioned properly . I loaded some and it worked fine .

If it has begun deteriorating, use it to burn stumps.