No cause that would be soooo illegal in terms of how the canisters are made. I'm 99% sure that if duster had CO2 stored inside it it would make the canister explode on the shelf if not during manufacture or transportation.
That being said it's actually difluoroethane (some may be tri or tetra) I believe the one you want is actually harder to find these days.
OP: Just take a screw driver or something and pry it off. From my experience it's kind of like taking the top off an Axe or Old Spice body spray can. Just get a screwdriver or something thin that you can push underneath get some leverage and pry it off.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE