A surgical mask is used inside the operating room or during other sterile procedure areas to protect the patient environment from contamination. Surgical masks have ties so that they can be adjusted for fit, and are tied over the top of a surgical or bouffant cap.
rockfall. 1  an act or instance of the falling of rock, as in a cave-in or an avalanche. 2  a mass of rocks that have fallen: to be trapped under a rockfall.
A rockfall or rock-fall[1] refers to quantities of rock falling freely from a cliff face. The term is also used for collapse of rock from roof or walls of mine or quarry workings.