Mercury (element) is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alternatives such as alcohol- or galinstan-filled glass thermometers and thermistor- or infrared-based electronic instruments. Likewise, mechanical pressure gauges and electronic strain gauge sensors have replaced mercury sphygmomanometers. Mercury remains in use in scientific research applications and in amalgam for dental restoration in some locales. It is also used in fluorescent lighting. Electricity passed through mercury vapor in a fluorescent
Safety barrier Safety barrier A safety barrier is a component which prevents passage into a dangerous area, commonly used to mitigate risk. Safety barriers may be hard barriers physically restricting passage or soft barriers that control circuits based on the presence of foreign bodies. A safety barrier is a component which prevents passage into a dangerous area. It is commonly used to mitigate risk in the Hazard-Barrier-Target model, as studied in safety science. Work Safe Victoria (an Australian organization) defines a Safety Barrier as a device that: Hard barriers are fixed or removable guards which prevent entry. There include fences, traffic barriers,