Googling, I find a couple references:
Store your primers in a cool, dry place away from sources of heat, and keep them in their factory packages because these are designed to protect the primer and to isolate the effects if one should detonate. Do not dump a bunch of them into some kind of jar or can. Trust me, you do not want to be anywhere around a bunch of exploding primers! MG Julian Hatcher relates a story in the 3rd edition of Hatcher's Notebook, page 525, about a technician in some ballistics lab bouncing down a hall with a bucket of primers. The darn things exploded with fatal consequences to the technician.
If you have a copy of Hatcher's Notebook (doesn't everyone?) read the section on primer explosions.....the story of the guy shaking a Mason jar full as he walked along....
The pictured box of primers is sitting on my wooden workbench. It doesn't get jostled.
But now you've got me thinking.