These thermometers are ideal for use in laboratories, universities, food/beverage, environmental, wastewater and many other general-purpose applications where the use of mercury or other hazardous liquids is not desired. Each thermometer features a black liquid and yellow back glass which creates a distinct contrast making this thermometer very easy to read. All Enviro-Safe glass thermometers contain an environmentally friendly non-mercury liquid that is 100% certified as non-toxic, non-hazardous, and fully biodegradable. In case of breakage the liquid can be cleaned up easily with soap and water. These thermometers come complete with ring top anti-roll fitting, individual serial number, statement of accuracy, recyclable packaging, and are RoHS compliant.