Wood smoke

Wood smoke: what is it?

Smoke from burning wood contains a vast array of compounds that are health and environmental hazards: fine particles, carbon monoxide (CO), volatile organic compounds (VOCs), nitrogen oxides (NOx) and several irritants.

Wood smoke: where is it found?

As you might guess, wood smoke comes from wood-burning appliances. And when it comes to pollution, not all stoves and fireplaces are created equal. According to Environment Canada, a non-certified wood stove emits as many fine particles into the air over a 9-hour period as does a certified model in 60 hours—or a mid-size automobile that is driven 18,000km!

Smoke gets into the air in your home in various ways: 

• When you open the fireplace or stove (e.g., to add more fuel); 

• It can leak through cracks in a defective or poorly maintained stove or fireplace; 

• If wood is burning in a nearby house, building or lot, the smoke can get in to your house through openings like doors, windows or an air exchanger intake.

How can wood smoke affect my health?

Some of the substances emitted when wood burns are carcinogens, pure and simple. Others, such as fine particles (smaller than the width of a human hair) can penetrate far into the lungs and have adverse effects on health.

Health impacts the very from one contaminant to another, and are more severe with high concentrations of contaminants in the air.

Potential impacts due to high concentration
of wood smoke in the air

_{Source: Direction de la santé publique de Montréal-Centre}

The health risks and effects, of course, vary depending on a person’s sensitivity. They are more severe for:

• People with existing cardiac or respiratory ailments, and for very young children; Children are more active than adults, so they breathe in more air. Smoke also affects them more, among other reasons because their respiratory systems are still developing.

• Elderly people and those suffering from asthma.

What should I do about wood smoke?

1. Make modifications to your existing fireplace

There are various things you can do to improve your fireplace's energy efficiency. We recommend dealing with specialists who are qualified to perform the necessary retrofitting in compliance with the National Building Code. 

2. Choose a new fireplace  

In Quebec, the Regulation respecting wood-burning appliances forbids the manufacture, sale and distribution of non-certified wood-burning appliances. 

Appliances certified by the U.S. Environmental Protection Agency (EPA) or the Canadian Standards Association (CSA Standard B415.1) heat more efficiently while releasing fewer contaminants.

If you live in Montreal, the only appliances you are authorized to use on a regular basis are those that emit a maximum of 2.5 g of fine particles per hour, in compliance with the latest updates to the EPA standard, which will apply nationally as of 2020.

3. Maintain your appliance

• Have your fireplace and chimney swept once a year or, if you burn more than six cords of wood per year, at mid-season as well;

• Have the entire system inspected and cleaned at least every three years by a technician certified by the Association des professionnels du chauffage.

4. Change your heating habits

• Burn less wood;

• Use clean, dry firewood that has been split and stacked properly to allow air to flow around the logs and dry them out;

• Opt for green products like densified wood logs. They emit 30 to 50% fewer toxic substances than natural wood and, what’s more, are 20 to 35% more energy-efficient;

• Don’t run your kitchen range hood when wood is burning in the fireplace: negative pressure (aka backdrafting) can cause smoke to be drawn into the house.

Health Canada: Avoid wood smoke