Much of our year-round comfort is brought to us by thermostats – those little boxes that sit on the wall and automatically turn the heating or air conditioning on or off to keep our homes and workplaces at a pleasant temperature.
But, did you know? Many of these thermostats contain one or more mercury switches.
The mercury is contained in sealed bulbs, so is quite safe during normal operation, but if that mercury is released through breakage, most likely during disposal, then it has the potential to contribute to environmental contamination and the ongoing disaster of mercury poisoning.
On average, these thermostats contain about four grams of mercury. That’s about the same amount found in 1000 fluorescent tubes or compact fluorescent lamps, and US data provides an indication of the scale of the problem. The mercury thermostats sold in the US in 2004 alone contained 14.5 tons (13.2 tonnes) of mercury.
The use of mercury in thermostats dropped significantly after California banned their sale in 2006. Total mercury sold in US thermostats in 2007 was down to 3.5 tonnes. However, these products have a long lifespan and a large number are still in use today.
Ecocycle’s Business Development Manager Daryl Moyle said while we don’t have hard data on mercury thermostats for Australia, he predicted the numbers would be high.
“Each floor of a high-rise office building might have half a dozen thermostats, most homes will have at least one, and there’s a variety of other building types with temperature controls. These thermostats don’t all contain mercury, but it’s reasonable to conclude that mercury-containing thermostats in Australia number in the millions,” he said.
So, what happens to mercury thermostats as they are replaced?
“Very few come to us for recycling, so it’s likely that most of them end up in landfill,” Mr Moyle said.
While many state governments have stepped in to ban mercury-containing lighting, Mr Moyle said he isn’t aware of any specific regulations applying to thermostats.
“Given the relatively large amount of mercury each thermostat contains, that’s something that needs to be addressed,” he said.
US leads the way
In 1998 several American thermostat manufacturers established a non-profit stewardship program called the Thermostat Recycling Corporation (TRC). In total, it has collected 2.1 million thermostats containing 10 tons (9.1 tonnes) of mercury.
“Logistically, the TRC model works in a similar way to our lamp and battery recycling programs so it’s something we could replicate quite easily,” Mr Moyle said.
“We will be talking to state governments and the HVAC (heating, ventilation and air conditioning) industry to better define the scale of the mercury thermostat problem as we investigate the development of a specific collection program.”
An important component will be educating HVAC contractors, building managers, demolition companies, office and shop fitters and home renovators of the existence and hazards of mercury thermostats, and appropriate disposal options.
Safely recycle mercury thermostats in Australia
Ecocycle can safely recycle the mercury contained in mercury thermostats.
HVAC contractors who are regularly replacing mercury thermostats are welcome to contact us on 1300 32 62 92 to discuss solutions. Or fill out the form below and we’ll be in touch.