The element Mercury has attributes that have made its use widespread across industrial, commercial and residential sectors. Historically it has been used in thermometers, switches, thermostats, dental amalgam, and even the process of gold extraction. However, mercury is a known neurotoxin and is highly toxic through inhalation or ingestion. Mercury has unfortunately become widespread in the environment. Manmade devices are one important source of mercury, which is why such devices are either banned or have switched to other mediums (e.g. mechanical switches). Many of these mercury containing devices still remain in use. Thermostats, which can hold up to 4 grams of mercury are still being used in Connecticut. For a state that relies on Waste-to-Energy, for MSW disposal, capturing these mercury thermostats when they are removed from service is critical.

In 1998 several manufacturers of thermostats created a voluntary program to capture and recycle mercury thermostats, headed up by the non-profit Thermostat Recycling Corporation. Tied to heating and cooling wholesalers, this program sought to capture thermostats removed by HVAC contractors. Unfortunately, this voluntary program has resulted in a very low capture rate ____(link) again.


Against the backdrop of high mercury levels in the New England region, including Connecticut, the sales of mercury thermostats were banned in 2004. To increase the capture and recycling of thermostats still in service, Connecticut passed Public Act 12-54 (link). This statute contains a variety of provisions:

  • Manufacturers must establish a program to recover mercury thermostats. In Connecticut they are relying on the existing Thermostat Recycling Corporation (TRC).
  • Containers for captured thermostats are provided to wholesalers, retailers, contractors, and municipalities. Wholesalers and contractors are required to participate by July 1, 2014, and cannot sell thermostats (of any type) unless they participate.
  • Demolition contractors must remove and recycle mercury thermostats prior to beginning demolition.
  • Mercury thermostats cannot be disposed of in MSW.
  • Multiple disposal options exist for old mercury thermostats, including the TRC program, HHW collection events, and municipal transfer stations.