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.
Rockfall. Falling rocks are a special category of the large family of gravitationally-driven phenomena called landslides. What are commonly called rockfall events generally fall into four technical definitions: rockfall, rock topple, rock avalanche, and rock slide.