If you are thinking along those lines, see if you can find some plastic coffee cans. The lids seem to snap on well. Maybe a covering made from saran wrap just prior to snapping on the lid may offer an additional seal. I use them mostly for storing brass and where I work there are plenty of empties.
I pulled about 45 rounds of Yugo 8mm last night, and put the powder in the Fritos can. At the local gun shop, they have the old metal powder containers. I might pick up one or two and move the powder to there.
As for identification, I peeled the label off the Yugo box and taped it to the container.