A significant number of thermostats still on the wall contain mercury, which is a potent neurotoxin. Mercury is used as a component of a mechanical tilt switch in thermostats, consisting of a glass bulb filled with inert gas and approximately three grams of mercury. Since many thermostats contain more than one switch, the average thermostat contains four grams of mercury. Even though 15 states now have laws that ban or restrict the sale of mercury thermostats, mercury thermostats can still be legally sold in the remaining states. In 1994, there were approximately 63 million mercury thermostats in use within the residential sector alone, equal to about 277 tons of mercury. Improper waste handling and disposal of mercury thermostats can result in mercury releases, and only a small fraction of mercury thermostats are being collected despite an industry-funded program run by the Thermostat Recycling Corporation. There are three major factors for the poor recycling performance of thermostat manufacturers: lack of awareness of thermostat recycling programs, an inadequate number of convenient collection locations, and insufficient motivation. PSI is working with stakeholders to develop effective state thermostat recycling programs that meet aggressive performance goals, and to conduct a pilot project for the collection of thermostats (and fluorescent lamps) at retail outlets.
