Thermos's ACCU-SAFE Non-Toxic Thermometers are filled with a biodegradable organic liquid and dye, which eliminates the hazards of mercury in the case of breakage and/or disposal. The safety-coated thermometers protect against breakage and contain the liquid and glass inside the coating for safety and easy disposal. A Certificate of Accuracy is included with each thermometer. Each thermometer is serialized and has blue liquid against a white background for ease of reading.