415 ILCS 5/3.284: Mercury switch.

"Mercury switch" means a product or device, containing mercury added during its manufacture, that opens or closes an electrical circuit or gas valve, or makes, breaks, or changes the connection in an electrical circuit, including, but not limited to, mercury float switches actuated by rising or falling liquid levels, mercury tilt switches actuated by a change in the switch position, mercury pressure switches actuated by a change in pressure, mercury temperature switches actuated by a change in temperature, and mercury flame sensors.