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
Food safety-risk analysis review and editing by food safety and science communities. A proper risk assessment is a constantly revolving process consisting of the following steps: (i) hazard identification, (ii) hazard characterization, (iii) exposure assessment, and (iv) risk characterization. "The identification of biological, chemical, and physical agents capable of causing adverse health effects and which may be present in a particular food or group of foods." This is often considered the most important step in a risk assessment as an unidentified hazard in the early stages of the production process can cause devastating effects in later stages. "The qualitative and/or quantitative evaluation of