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Safe Mercury Thermostat Disposal for California Residents

Do you have a mercury thermostat in your home or workplace?

Many thermostats sold prior to 2006 contain a glass tube or “switch” of liquid mercury, which is toxic and hazardous to human health. That’s why in the state of California, it is illegal to dispose of a mercury thermostat in the trash. Instead, mercury thermostats must be disposed of at a qualified drop-off location to be recycled.

If you are a California resident looking to upgrade your old mercury thermostat or a service technician removing one or multiple from a building or facility in the state, make sure to properly dispose of it at a drop-off location and earn a $30 mail-in rebate per mercury thermostat in the process.

step 1:

Wearing protective gloves, carefully remove the thermostat from the wall and place it inside a sealed clear bag – collection locations may have these bags available if you do not. Do NOT disassemble or attempt to remove the mercury-containing glass tube inside the thermostat. Drop-off locations will not accept broken or disassembled thermostats.

step 2:

Enter your zip code to find your drop-off location here.

Step 3:

Download, print, and fill out the rebate form to receive a $30 mail-in rebate per mercury thermostat. Collection locations should also have these forms available and with carbon-backing to supply a copy of the form for you.

step 4:

Take your thermostat and completed rebate form to your drop-off location and speak with the location’s associate to place it in the labeled mercury thermostat drop-off container. Make sure the location’s associate staples the rebate form to the outside of a Ziploc bag with your mercury thermostat to keep those items together for processing. If you don’t use a carbon-backed rebate form from the location, take a photo of your form for reference. We advise you to also take a photo of your thermostat for reference of its applicability for the rebate.

Step 5:

You will receive your rebate in the form of a check when the thermostat has been verified as a mercury thermostat and processed at the safe disposal center. This process may take up to one year. If you have questions about the status of your check or would like to update your mailing address, please email

  • Mercury thermostats use a mercury switch/bulb inside the device to control room temperature. Through circuits, the mercury communicates with your furnace or air conditioner to keep a desired room temperature.
  • Was your thermostat purchased 2006 or later? Most likely, it is not a mercury-containing thermostat.
  • Digital thermostats do not use mercury.
  • If your thermostat was purchased prior to 2006 and is not digital, there is a chance it could contain mercury.
  • Note: Fully intact mercury-containing thermostats are safe. As long the mercury remains sealed in the glass bulb, and the glass is protected by the thermostat cover, you are unlikely to be exposed to mercury. It is important to handle mercury thermostats with care and dispose of them properly so that the sturdy casing, and the sealed glass bulb inside, remains intact.
  • Below are some example photos of mercury thermostats:

The following downloadable materials are available to help you learn more about thermostat recycling and share information with fellow neighbors, friends, and family members:

Commonly Asked Questions

How do I know if I come across a mercury thermostat?

To determine if your thermostat contains mercury, inspect the thermostat to see if it contains a lever or dial to control the temperature. Thermostats with this feature typically contain mercury. Homes or buildings whose HVAC systems haven’t been updated since the early 2000s. Areas of the state that may be lower income and therefore not updating their HVAC systems regularly or in the past decade. 

Why do mercury thermostats require special disposal?

In normal use, mercury-containing thermostats are safe and do not expose people to mercury. However, if mercury thermostats are improperly handled or disposed of, the glass tube of liquid mercury may break, causing the mercury to vaporize. This can cause serious health problems – particularly among children and pregnant women. Mercury-containing thermostats that are not disposed of at a hazardous waste collection site can expose sanitation workers, soil and groundwater to toxic mercury contamination. So, improper care and disposal of mercury-containing thermostats are dangerous to both public and environmental health.

What are the health risks of being exposed to mercury?

Mercury is toxic and exposure even in small amounts may cause serious health problems. Breathing mercury vapors can harm the nervous system, lungs and kidneys. Mercury vapors can also pass easily from the lungs to the bloodstream. Children under 14 are more sensitive to mercury than adults because of their developing brains and nervous systems – and may be irreversibly damaged by it. Mothers who are exposed to mercury and breast-feed may also expose their infant children through their milk.

What are the consequences of throwing a mercury thermostat in the trash?

Failure to properly dispose of mercury-containing thermostats can result in a $70,000 fine.

Who is eligible for the rebate?

A $30 per mercury thermostat incentive is available to consumers or service technicians that attests, under penalty of perjury, to both of the following:

• Their California state residency.

• That the returned mercury thermostat(s) were removed from a building or facility in California.

Any additional questions? Email