What Happens To Your Old Mercury Thermostat?

Do you live in an older building with a round thermostat on your wall? Millions of Americans do.

If you do, or if your thermostat is more than ten years old and not electronic, chances are it contains one or more mercury switches. As recently as 2004, American manufacturers (principally Honeywell, White Rodgers, and General Electric) used almost 14.5 tons of mercury annually to produce thermostats, the average thermostat containing about four grams of mercury .

This mercury becomes a serious problem when the old thermostats are replaced and then discarded.  If the glass ampoule containing the mercury is broken or crushed during waste handling or disposal, the mercury will be released into the environment since mercury is volatile at room temperature. At least some of this mercury ultimately finds its way into our waterways, builds-up in fish each time a larger fish eats a mercury-tainted prey, and contributes to the widespread fish consumption advisories throughout the country issued to protect children from the chemical’s harmful effects to their development.

Keeping mercury thermostats out of the trash, and ensuring their safe and proper management, is ostensibly the goal of a voluntary industry-sponsored program set up by thermostat manufacturers. They created a non-profit corporation called the Thermostat Recycling Corporation, or TRC, and started collecting mercury thermostats nationally (except in Alaska and Hawaii) in 2001. 

Unfortunately, the program is not working well, and, in fact, is collecting only a small percentage of available mercury thermostats, as documented in a recent report issued by NRDC and other organizations. The report, Turning up the Heat II, is our second review of the program; after the first report TRC stopped publishing its state-by-state program results on the actual number of mercury thermostats and the actual amount of mercury collected (except where state law requires TRC to submit the data), making it more difficult to find out what’s going on.

The experience of the TRC program in California is both instructive and important for the future. Faced with a program that collected fewer than 6,000 thermostats in 2007, California enacted legislation in 2008 mandating a collection program for thermostat manufacturers, and requiring the manufacturers to estimate the number of mercury thermostats available for collection annually. The law also requires the California Department of Toxic Substances Control (DTSC) to issue rules specifying quantitative performance standards for the TRC program, and to make changes to the TRC program if those standards are not met.

TRC’s 2009 study found that between 5.1 million and 10.5 million mercury thermostats were still in use in California, containing (at four grams of mercury per thermostat) between 22.5 and 46.2 tons of mercury.  TRC also reported that over the next seven years, more than 200,000 mercury thermostats would be coming out of service every year, and over the next 16 years after that, more than 100,000 mercury thermostats would still be coming out of service annually.  

In 2011, TRC collected 19,927 mercury thermostats in California, representing 4.1% to 8.5% of the available mercury thermostats that year in California according to TRC’s study. In 2012, TRC’s collection results declined to 18,291 mercury thermostats, representing 4.1% to 8.6% of the available thermostats for that year.

Within the next several months, DTSC will finalize the mandated quantitative performance standards for the program. Once this happens, TRC will be held accountable for its lack of performance to an agency with explicit statutory authority to compel program changes when standards are not achieved. Beyond California, the states of Illinois and Rhode Island have similar statutory frameworks and upcoming rulemakings.

One program change expected to surface in California if TRC does not meet the required performance standards is the use of a financial incentive payable to contractors and homeowners to encourage thermostat returns. Financial incentives have been proven to increase collection rates.  Maine and Vermont, the two states thus far with financial incentives, have the highest per capita collection rates in the country.  Nevertheless, TRC and the thermostat manufacturers argue the incentives are not effective because not everyone who turns in thermostats in those states requests the incentive. So what? Not everyone who buys a product waits for a sale or a rebate from the manufacturer, but overall sales are higher because many take advantage of the incentive. If the objective is to increase collection rates, and the incentive spurs a significant portion of the contractors to do the right thing, then it is working. And it will be more effective than relying upon enforcement alone, given the number of contractors involved and the challenges involved with catching a contractor throwing a mercury thermostat in the trash.

We’ll be watching developments on this issue in California and other leading states closely because there’s an important opportunity here for preventing needless mercury pollution.