It’s illegal in the state of California to throw out a mercury thermostat with your regular trash. There is a fine of up to $70,000 for each mercury thermostat that is not recycled. The Thermostat Care safe thermostat recycling program of California helps individuals and businesses properly dispose of old mercury thermostats that pose a health hazard to communities and the environment. Consumers Contractors HHW Retailer/Wholesaler Find Locations by County.