Yes, pellet stove smoke is toxic and should not be breathed in. Every effort should be made to ensure the pellet stove smoke is exhausted away from where people are congregating.
Burning biomass toxins are carcinogenic. Carcinogenic means “having the potential to cause cancer“.
See below extract from an article published by the National Library of Medicine titled “Potential adverse health effects of wood smoke”.
“Wood smoke is known to contain such compounds as carbon monoxide, nitrogen oxides, sulfur oxides, aldehydes, polycyclic aromatic hydrocarbons, and fine respirable particulate matter. All of these have been shown to cause deleterious physiologic responses in laboratory studies in humans. Some compounds found in wood smoke–benzo[a]pyrene and formaldehyde–are possible human carcinogens.”
Pellet stoves are not unique to creating toxic smoke. All burning biomass (aka wood) produces some sort of toxicity content in the smoke.
Pellet stoves will typically produce less smoke than most other forms of biomass heaters. Pellet stoves produce less smoke than traditional wood stoves because the pellets are very clean burning when compared to other fuels like firewood and coal.
Pellets are produced with a very low moisture content and therefore burn hot and clean. A hot and clean burn vaporizes most of the smoke and any toxins with it. This however does not mean there are no toxins, just less toxins.
Another reason pellet stoves produce less toxins is that the material the pellets are manufactured from is very consistent, and contains very few contaminants. Pellets are usually made of the primary ingredient only, that being any of the following, wood shavings, sawdust, cane mulch, tree bark, and many other similar biomass products. This is great for people with asthma who operate pellet stoves.
You can learn more about how pellets stoves work here.
How to reduce the risk of inhaling toxic pellet stove smoke
- Ensure the pellet stove is regularly maintained.
- Ensure the pellet stove door is not left open when operating.
- Clean the pellet stove regularly, pay particular attention to door seal, ensure they maintain a tight seal.
- Clean the flue regularly, a clear free flowing flue helps to ensure a good draft, which help draw the smoke out the flue.
- Do not burn pellets that are wet or have been contaminated in some way.
- Ensure the pellet stove is installed by a professional, the flue should be positioned so that it exhausts smoke well away from where people congregate. The flue should not be placed near windows or other roof vents.