Mercury is the only metal that is liquid at room temperature which vaporizes quickly. The vapors are colorless, tasteless and odorless and are virtually undetectable without specialized equipment. These characteristics enable repeated and prolonged exposure to occur. Symptoms of prolonged exposure include nausea, depression, inflammation of the mouth and gums, allergic reactions and damage to the central nervous system which is irreversible. In addition, when mercury is improperly disposed, it can bioaccumulate in natural ecosystems, adversely affecting many top predators.
In an effort to eliminate mercury from the University of Texas Health Science Center Houston, the Environmental Protection Program has established a Mercury elimination and reduction program. This program consists of systems designed for recycling mercury containing lamps, thermometers, dental amalgam and batteries, as well as providing non toxic thermometers to researchers in exchange for mercury containing thermometers.
These replacement thermometers, which are manufactured by Miller & Weber Inc. contain PerformaTherm which is the first non-mercury thermometer with the performance of mercury. The blue liquid is safer than both mercury and most traditional spirit thermometer liquids. The proprietary formula is biodegradable, nontoxic, noncaustic, and nonhazardous. PerformaTherm meets all ASTM standards for accuracy, tolerance and uncertainty; performance measures are shown in the chart below.
Performance Comparison for Thermometers (Miller & Weber, 2003)
|Tolerance||+-0.1 ºC||+-0.1 ºC||+-2.0 ºC|
|At Ice||+-0.02 ºC||+-0.02 ºC||+-0.5 ºC|
|Over Range||+-0.05 ºC||+-0.05 ºC||+-0.5 ºC|
|Response Time||< 3 min||< 3 min||15 min|
Researchers can request to trade in their mercury containing thermometers for non toxic thermometers, at no cost, by calling 713-500-5837, or by emailing CATER@uth.tmc.edu. PerformaTherm thermometers range from -20 °C to 110 °C.