Mercury and other heavy metals, improperly managed, pose danger to human and environmental health. Common sources of mercury include, thermometers, light bulbs, and thermostats. Used mercury thermostats have no place in our landfills and should be properly recycled. Replacing mercury thermostats with energy saving programmable electronic thermostats increases the opportunity to prevent pollution.


There are more than 50 million mercury-containing thermostats in homes across the United States. Mercury has been used in thermostats since the 1950s.
A mercury-switch thermostat uses mercury in a sealed glass bulb. Each bulb contains approximately three grams of mercury, which is about the size of a dime. (These facts provided by Honeywell, Inc.)
liquid mercury


Elemental Mercury
symbol= Hg,
atomic number= 80,
density= 13.53 g/ml

Peaks to Prairies provides the following information and related links for states and regions wishing to develop mercury thermostat recycling programs based on the success of the Montana Weatherization Program. Please contact Mike Vogel if you have questions or need further assistance. Montana Mercury T-Stat Recycling Logo

In the fall of 1999, the Montana State University Extension Service developed a program to reduce the amount of mercury going into Montana landfills from mercury containing thermostats. The Montana Department of Public Health and Human Services (DPHHS), Human Resources Development Council (HRDC) and MSU Extension Low Income Weatherization Assistance Program were the partners needed to make this happen. HRDC technicians make weatherization improvements to homes across the state including up to 2000 furnace modifications and changeouts throughout the year. To implement the mercury reduction program, the Weatherization Program (with funding from DPHHS) provided training to technicians to properly collect and recycle the many mercury thermostats discovered in these retrofits.

Technicians collect mercury thermostats from clients and store them in a padded envelope in a lined PVC bucket. The bucket is properly labeled under “universal waste regulations“.  Accompanying each bucket is a thermostat collection log, MSDS sheets and a mercury spill clean-up kit. Technicians turn in thermostats to an Extension Service representative at quarterly or semi-annual trainings. The thermostats are then taken to an approved storage facility and shipped to a recycler when an appropriate number is accrued. With increasing national concern about PBT’s, this has been an effective measure to prevent air, soil, and water problems caused by this obvious source of mercury in landfills in our region.




Click on the following links to read about other programs in Ohio and Indiana.

Montana’s program takes P2 one step further by replacing the mercury thermostats with electronic programmable thermostats  adding an energy conservation component.  With traditional thermostats, the same temperature is maintained unless the occupant is diligent in manually adjusting the unit.  Programmable thermostats allow for automatic adjustments while occupants are asleep or away from home.  Programmable thermostats offer as much as a 50 percent rate of return. (Source: Energy Efficiency & Renewable Energy Network, Business sponsor Johnstone Supply of Billings  contributed financially to this aspect of the program which  Montana State University Extension Service continues to manage.

Examples of Documents Used in the Program:
Mercury Thermostat Collection Protocol (pdf)
Programmable Thermostat Installation Log (pdf)
Mercury Thermostat Removal Log(pdf)

Recycling Opportunities:
Ohio EPA  Office of Pollution Prevention – list of recyclers
South Dakota  DENR – list of recyclers
Salesco Systems USA: 800/368-9095
Bethlehem Apparatus
Mercury Waste Solutions Incorporated

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