Abstract: A hand-operated canister opener tool, and method, for opening a frangible, plastic-walled, hollow canister (such as one containing a cryptographic, secret, military code) having two pivotally connected elements carrying a canister piercing member for piercing the canister to examine its contents before discard, and a canister receiving member surrounding the canister for safety during piercing for preventing ejection of shrapnel-like, sharp, plastic chips likely to cause bodily injury.