Less than five percent of the tens of thousands of thermostats containing mercury that are removed annually from California homes and commercial buildings are recycled. Discarding this toxic material with household trash is dangerous and against the law.

California's Mercury Thermostat Collection Act of 2008 requires contractors, wholesalers, and manufacturers to collect and recycle all mercury-filled devices they remove from service. The law specifically requires contractors who remove mercury thermostats to:

• Leave the thermostat and mercury ampoule (glass bulb) intact.
• Store the device in a container labeled “Universal Waste—Mercury-Containing Equipment.”
• Take the stored thermostats to a recycling facility within one year of removal.

A 2009 survey cited by the state Department of Toxic Substances Control (DTSC) indicated that C-21 Building Moving/Demolition contractors and C-20 Warm-Air Heating, Ventilating, and Air-Conditioning (HVAC) contractors remove approximately 300,000 mercury-filled thermostats each year. Last year, only 13,340 thermostats were recycled, which illustrates that contractors are a critical first link in recycling mercury thermostats.

The law recognizes wholesalers and distributors as a second critical link and requires these businesses to provide thermostat collection bins inside their facilities. This makes it simple for contractors to regularly drop off any mercury thermostats they have removed. Older thermostats that were installed up until the early 1990s each contain approximately three grams of mercury. Improper disposal of these thermostats means tons of mercury could reach the state's landfills, waterways, and residents.

For more information on proper mercury disposal, check DTSC's website or call 1-800-728-6942.