Unsafe without a hole: a dangerous cryoextractor.
Due to the absence of an exhaust hole for the expanding gas, a disposable cryoextractor shot its activator button like a bullet out of its top against the ceiling--barely missing the head of the assisting surgeon.
D002387:Cataract Extraction / Q000295:instrumentation*; D003452:Cryosurgery / Q000295:instrumentation*; D004209:Disposable Equipment / Q000592:standards; D005107:Explosions; D006801:Humans; D008875:Middle Aged; D013525:Surgical Instruments / Q000592:standards*