Period 6 element 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 alcohol-filled, galinstan-filled, digital, or thermistor-based instruments. It remains in use in scientific research applications and in amalgam material for dental restoration. It is used in lighting: electricity passed through mercury vapor in a phosphor tube produces short-wave ultraviolet light which then causes the phosphor to fluoresce, making visible light. Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray other metal resembles tin but discolors when exposed to air. The
Process safety management tested and operating in a safe manner. A process includes any group of vessels which are interconnected or separate and contain Highly Hazardous Chemicals (HHCs) which could be involved in a potential release. A process safety incident is the "Unexpected release of toxic, reactive, or flammable liquids and gases in processes involving highly hazardous chemicals. Incidents continue to occur in various industries that use highly hazardous chemicals which exhibit toxic, reactive, flammable, or even explosive properties, or may exhibit a combination of these properties. Regardless of the industry that uses these highly hazardous chemicals, there is a potential for an