A fiery stack of wood logs.
Wood-burning stoves can emit fine particulates and nitrogen oxides, among other pollutants.

Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2021. E&E News provides essential news for energy and environment professionals. 

Even as the federal government and states dangle tax breaks to encourage sales, buyers of new wood stoves can’t be sure that their purchases aren’t spewing dangerous levels of pollutants, according to a biting new report that calls for an investigation by either Congress or the agency’s inspector general.

Stoves and other appliances — which the report says are used in millions of homes as an energy source — are a top source of fine particulates, commonly dubbed soot, linked to a variety of cardiovascular and respiratory problems, including higher odds of premature death in some circumstances.

Yet EPA’s current system “provides no confidence” that stoves and other wood-fired heating appliances perform at the level required by federal standards, Northeast States for Coordinated Air Use Management (NESCAUM), a group of state air quality regulators, said in the report, released Monday.

Among the specific concerns raised by the Boston-based group: testing that may give an artificially low reading of the amount of pollution that stoves and other wood-fired hearing appliances spew in real-world conditions, slipshod test certification procedures, and lax EPA oversight.

“You can’t assume because it’s EPA-certified that it was tested according to the requirements,” Lisa Rector, a program and policy director for NESCAUM and the report’s lead author, said in an interview.

At stake is whether stricter Obama-era emissions limits that took full effect last year are in fact delivering on forecasts of less pollution.

“If EPA’s program for certifying wood heaters is not assuring that new devices are in fact cleaner than the ones they are replacing, then these efforts may be providing no health benefits while wasting scarce resources,” the report says, calling the certification program a “systemic failure.”

The group, made up of air pollution agencies from eight states, calls on either Congress or EPA’s inspector general to scrutinize two EPA branches — the Office of Enforcement and Compliance Assurance and the Office of Air Quality Planning and Standards — “with a focus on identifying practices to improve agency oversight and enforcement” of the wood stove program.

In an email, an EPA spokesperson did not address the report’s specific findings but said agency officials are working to understand the concerns raised by NESCAUM and other entities.

At the Hearth, Patio & Barbecue Association, a trade group for stove makers and retailers worried that states could begin setting their own regulatory regimes, spokesperson Emily McGee said in a statement that the industry has faith that EPA is “using the appropriate methods to ensure a consistent and respectable certification program.”

“Allegations that this process is not working as planned need to be carefully studied and if needed, adjustments made,” McGee said.

At the Alliance for Green Heat, another advocacy group often critical of the industry’s positions, President John Ackerly said the report fails to acknowledge that the current system has resulted in a “breed of far, far cleaner stoves.”

“By and large, I think the system is not nearly as broken as this report suggests,” Ackerly said in an interview. But the findings do indicate “a huge need for EPA to get more serious,” he added.

In 2015, the Obama-era EPA strengthened the standards on new stoves and other hearers for the first time in more than a quarter century on a two-step implementation timetable. Despite industry lobbying for a delay, the second step took effect last May as scheduled, although the Trump administration made clear that it would do little to stop the sale of higher-polluting models that dealers still had in stock.

By EPA’s projections, the stricter limits have already cut releases of fine particles, volatile organic compounds and carbon monoxide by thousands of tons annually. Over the long term, the expected health savings are supposed to be in the billions of dollars.

But those forecasts hinge on the presumption that newly made appliances actually comply with the standards. In the report, the regulators group found grounds for doubt. EPA’s system for certifying that new heaters meet the latest standards is dysfunctional and “easily manipulated by manufacturers and testing laboratories,” the authors write.

Researchers found that certification labs routinely rely on “atypical” burn methods that produce better emissions results but are unlikely to be used by the average homeowner, according to the report. While EPA in mid-2019 identified “discrepancies and concerns” about unusual testing conditions, 40 certified test reports filed after that point “continued to contain at least one of the problematic practices” previously singled out by the agency, it says.

And while EPA first adopted emissions standards for new wood-fired appliances in 1988, it has yet to carry out a single audit to verify that a specific model “actually performs consistent with its certification test results,” the report says.

Meanwhile, 10 states, including Idaho, New York and Maryland, now offer tax breaks or rebates to encourage the purchase of new home heaters.

As part of a $900 billion COVID-19 relief bill passed late last year, the federal government also hopped aboard the biomass bandwagon by offering a 26% tax credit toward stoves that meet a set efficiency threshold.

In addition, so-called change-out programs subsidized by taxpayers or enforcement settlement money have spent millions of dollars in recent years to replace older appliances with cleaner-burning models. But in Libby, Montana, where every stove not certified by EPA was replaced from 2005 to 2008, studies later found that the drop in particulate matter emissions was far less than predicted, according to the report.

“This history indicates that without reliable certification procedures,” the authors wrote, “replacing old stoves with newer models may not result in pollution reduction benefits.”