Recycle Your Old Thermostat

Mercury thermostats use mercury switches to control room temperature through communication with HVAC equipment. Older thermostats often contain mercury. Is it time to recycle your old thermostat?

Mercury thermostats have bi-metal coils that contract and expand with room temperature. When the coil contracts or expands, it activates the mercury switch, which opens or closes a circuit to make the furnace, heat pump or air conditioner turn on or off.

The amount of mercury in each thermostat largely depends upon the number of switches it contains. The mercury in a thermostat will pollute the air, land or water if not managed properly at the end of its useful life. The mercury could be released if the thermostat is broken, crushed or burned during waste handling at a landfill or incinerator.

Even in small quantities, mercury can cause significant health and environmental problems. Mercury released into the atmosphere can be transported long distances and deposited in aquatic eco-systems, where it converts to methyl mercury – the most toxic form. This is why it is so important to recycle your old thermostat.

Mercury is a danger to the development of babies and young children. The CDC estimates that 300,000 to 630,000 infants born in the U.S. have mercury levels that are associated with loss of IQ. New evidence indicates that methyl mercury exposure may increase the risk of cardiovascular disease in humans, especially adult men.

Methyl mercury accumulates and magnifies in the food chain, so for people, the main source of exposure is in fish consumption. If mercury accumulates and reaches levels that pose risks to humans, states issue fish consumption advisories to provide information to their residents on the amount and types of fish that are safe to eat.

Twenty-seven states have statewide advisories for all their fresh water lakes and rivers, and 13 states have statewide advisories for their coastal waters. So for the safety of all, remember to recycle your old thermostat!