Mercury can be found in various devices in residential buildings. When a mercury-containing product breaks and the mercury is spilled, the exposed mercury can evaporate and become an invisible, odorless toxic vapor. To prevent mercury releases, these products should be used and stored safely, and managed properly at the end of their useful lives. This fact sheet specifically addresses pre-demolition removal of mercury-containing gas pressure regulators, mercury-containing boiler heating systems, and thermostats. For information on proper removal and management of other mercury-containing products in homes, go to and