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
Explosives safety of Former Used Defense Sites (FUDS) and Former Toxic Chemical Agent Sites where munitions from all branches of service disposed of A&E by burial or dumping up until the end of the Vietnam War. The USATCES acts as the Army’s safety watchdog for disposal of chemical ammunition at the Army’s Chemical Disposal Facilities. As part of Army's Ordinance Corps under TRADOC Specially trained Civilian Explosives Safety Personnel [Quality Assurance Specialist (Ammunition Surveillance) (QASAS)] and Safety Specialist that have received specialized training in A&E Safety) from the USATCES are deployed worldwide, wherever the U.S. Army has A&E. Their mission is to