Primers in anything other than their original packaging will mass detonate. The risk is low but if one goes off, ther rest will.
I can remember old primer packaging where they were stacked in 10 rows of 10 each. Each row was only divided by a thin plastic strip and I can guess if one went, the whole thin could. Now they are all packed in their own compartment so its pretty safe.
As far as primer feed devices, Dillon has the best except when you are loading the pick-up tubes. I can see the whole thing going off in one's hand. Not a pretty sight. The feed tube on the machine is isolated by a heavy steel pipe that is vented at the bottom. The top would geyser the ceiling with primer cups, anvils and debris but the bottom would be the biggest vent. Its pretty safe. The RCBS/Blount CCI APS strips and machines are the safest but one must load the strips unless you are willing to buy only CCI and pay the premium for this packaging and equipment.
Other things I would worry about are plastic primer flip trays and feed mechanisms. I don't know if the plastic is a static dissipative type of material and I can see a problem arising from dust and static electricity setting it off. Here again, Dillon has a zinc tray that's not only conductive (no static problems), but also non-sparking.
Penetrating oil will desensitize priming compound but its still explosive. Cleaning the equipment/area with isopropyl alcohol until all green/yellow residue is gone is the only way to stay safe and not contaminate primers.
Primers are noting to fool with. I've heard of anvils and cups launched with sufficient velocity to imbed in muscle form an errant detonation.
WEAR YOUR SAFETY GLASSES! Handle bulk primers only in counts of 100 or less. Use tweezers to pick up spilt primers and account for all primers. Oh yes, wash your hands after any reloading as lead is everywhere thanks to the primers.