If the powder is in labeled containers, it should be ok, just start at minimum loads and work up, sometimes manufacturers will make a powder of the same name and will change its characteristics slightly over time.
If the powder looks like it has been mixed, get rid of it- as someone else mentioned, dump it on your lawn.
Do any of you use Hercules ( now Alliant) 2400? If so how strong is the oder?
I'll check mine when I get home in the morning.