Residential wood burning has been increasing in Minnesota. The majority of wood burned is for home heating, but recreational fires are the most common reason people burn wood. The increase is concerning because 51% of direct fine particle emissions in the state come from wood burning. Wood smoke also contains wood tars, gases, and soot, and chemicals such as carbon monoxide, dioxins, and volatile organic compounds (VOCs).
People who frequently breathe wood smoke are at risk for serious adverse health effects. Short-term exposure to fine particles in the air can aggravate lung disease, trigger asthma attacks and acute bronchitis, and may also increase the risk of respiratory infections. Scientists have also linked short-term exposures to heart attacks and abnormal heartbeats. Over time, breathing fine particles increases the chances of developing chronic obstructive lung disease (COPD), chronic bronchitis, cardiovascular disease, or lung cancer. In high concentrations, wood smoke can permanently damage lung tissue. Young children, the elderly, and people with asthma, lung, or heart disease are especially vulnerable to these effects.
In 2020-2021, Minnesotans burned 1.54 million cords of wood — enough to fill US Bank Stadium to overflowing!
Minnesotans use an estimated 290,000 wood-burning units such as stoves, furnaces, and boilers. About a third of them were manufactured before 1989, and pollute much more than current models. New wood-burning appliances sold in Minnesota must be EPA-certified to 2020 emission standards; dealers selling models that aren’t certified are violating the law.
If you're in the market for a wood-burning appliance, buy from a reputable dealer and have it installed by an National Fireplace Institute (NFI)-certified technician. Buy the right size for your home, and compare the listed emissions of stoves that you are considering. Often the lowest-polluting appliance is also the most efficient, meaning that they provide more heat per cord of wood.
For a few Minnesota counties, the Environmental Initiative offers financial incentives for stove upgrades through its Project Stove Swap. The program offers money to households in the Twin Cities metro area and several counties in northeastern Minnesota for swapping older, inefficient wood burning stoves for new models.
Open and recreational fires
The most important things we learned from our study on recreational fires is that small fires using clean, dry wood give off the least emissions.
The state fire code limits the size of outdoor recreational fires and portable fireplaces to 3 feet across. Anything larger requires a burn permit from the Minnesota Department of Natural Resources (DNR), which regulates open burning to minimize the risk of wildfires.
Consider alternative options for recreational fires, such as propane-fueled or “low-smoke” wood-burning fire pits. And it’s a good idea to check with your neighbors to make sure they are okay with it.
Local governments may set more stringent regulations for backyard recreational fires, such as restricting fires on air quality alert days, allowing them at certain times, or requiring permits. Check with your city and county to learn about restrictions in your area.