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
Toxic Substances Control Act of 1976 safety studies. In this extent of TSCA, the EPA’ s ability is restricted to share information including the company’s identities, the chemical’s structures to any public groups except the designated contractors, or to law enforcement officials. It is important that the state and local environmental non-governmental agencies, environmental advocates and other public groups in obtaining chemical information in order to develop contingency plans and effective emergency responses in cases of highly toxic exposures. However, the EPA can only disclose confidential business information when it determines such disclosure is necessary to protect human health or the environment from an unreasonable risk.