Thermometers Illegal in Garbage & Drains Contains Mercury Household Hazardous Waste HHW must be dropped off by appointment – click for more info. How to Check for Mercury A silver, metallic liquid will be visible from inside the bulb or vial if the thermometer contains mercury. Do Not Put in Garbage Thermometers containing either mercury or digital components should be disposed of as hazardous waste. Never throw them in the garbage. Digital Thermometers Are E-Waste Remove any batteries and dispose of them as household hazardous waste. Then dispose of digital thermometers as e-waste because they contain small electronic parts. Ways to Reduce Don't Buy Mercury Mercury is a highly toxic substance. Avoid purchasing mercury to reduce the amount that leaches into lakes and rivers. Invest in Quality To reduce waste, invest in a quality thermometer that will last a long time. Did You Know? Mercury-Free Medical Devices Only Decades ago, healthcare facilities in U.S. and Europe were responsible for contributing most of the mercury polluting our environment. Once they realized the dangers of mercury exposure, they phased out the use of medical devices containing mercury.