Many Americans are looking to escape high heating bills and have found what seems to be the perfect solution: outdoor wood boilers. Commonplace now along rural roads, they look like sheds with chimneys on top, and circulate water into homes for heating systems or hot water.

But they aren’t as innocuous as they may look. Which is why Earthjustice, on behalf of several health and environmental groups, filed a lawsuit Wednesday over the EPA’s failure to update standards for these units. But we aren’t the only ones crying foul. Filing a similar complaint were the states of New York, Connecticut, Maryland, Massachusetts, Oregon, Rhode Island, and Vermont and the Puget Sound Clean Air Agency.

The issue in a nutshell: these units emit high volumes of particulate matter (which can lodge deep within the lungs causing serious cardiovascular and respiratory harm) carbon monoxide, nitrogen oxides, volatile organic compounds, hazardous air pollutants and carcinogens. We know all these chemicals are toxic soup for our lungs and health. And EPA’s failure to update the standards means that homeowners install thousands of new wood-burning boilers, furnaces and stoves each year that produce far more dangerous air pollution than cleaner units would.

In fact, according to this Albany Times Union story, in 2008 the New York attorney general’s office found that outdoor wood boilers emit far more soot than other residential wood heaters, about 12 times as much soot as EPA-certified wood stoves, 1,000 times as much as oil furnaces, and 1,800 times as much as gas furnaces.

What we are seeking in our lawsuit is essentially for the EPA to fulfill its obligations under the Clean Air Act. The agency determined in 1987 that these units “contribute significantly to air pollution which may reasonably be anticipated to endanger public health and welfare”, and the law requires the EPA to review emissions standards for such health harming sources of air pollution every eight years. Under the law, the EPA should have reviewed and updated the standards in 1996, 2004 and 2012.

Here is what Tim Ballo, the Earthjustice attorney handling this case, had to say about the lawsuit:

Woodsmoke from these devices is a significant source of dangerous fine particulate matter and because they emit close to the ground and their use is concentrated in certain areas including the Northeast, Northwest and Midwest, they have an enormous impact on wintertime air quality in those areas. The EPA needs to update its standards, which fail to cover the most heavily polluting types of wood burning equipment.