How old is too old?

[Cold Spring]

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.

[James L. Martin]

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

[6pt-Sika]

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 .

[Mike of the Mountain]

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