The bill by Democratic Assemblyman Ira Ruskin would require manufacturers to set up and maintain collection and recycling programs for old thermostats.  Sierra Club California Director Bill Magavern says those contain considerable amounts of mercury-- a toxic metal that can affect brain and nerve function. Magavern says you can’t just throw those old thermostats away. 

 “Even though it’s against California law there’s almost nobody who knows it’s against the law and even when they do know there are not many free and convenient ways for people to recycle their old mercury thermostats…” 

A lobbyist for Honeywell—who makes thermostats says the company is working with the author of the bill.  Some manufacturers including Honeywell have already established a program for recycling.