Woodsmoke from indoor and
outdoor burning is unhealthy, especially for kids and adults with asthma, bronchitis
or other lung conditions. Here are some
important tips for reducing
woodsmoke and burning cleaner fires:
How is woodsmoke unhealthy?
In a conventional fireplace or
older woodstove, smoke and fumes such as carbon monoxide
are released directly into the air inside and around your home. When cold air is present,
invisible particles from the smoke stay close to the ground, penetrating nearby homes and
buildings. These particles are so small that when we inhale, they completely bypass our
usual defense system - the nose and upper respiratory system. Instead, they lodge deep in
the lung tissue, triggering chemical damage and structural changes.
Health impacts range from minor
irritation of the eyes, nose and throat, to significant
and long-term damage to the cardio-respiratory system.
Perhaps one of the most
important things to be aware of, however, when considering the
safety of your fireplace or woodstove, is the potential for back drafting of carbon
monoxide, a colorless, odorless toxic gas created by incomplete combustion. Back
drafting, which brings the toxic gas back into your home, can occur when a fireplace flu
is blocked, disconnected or leaking. Carbon monoxide can cause flu-like symptoms (nausea,
headache, fatigue) to more serious conditions, such as chest pain or asphyxiation. If
you suspect your woodstove or fireplace is not adequately vented, itís good peace of mind
to have it serviced and inspected by a professional.
The most vulnerable members of
our families are those who have respiratory conditions,
such as asthma, bronchitis, emphysema or a heart condition. Infants and children are at
risk as well though, even when healthy, since woodsmoke damages their developing lung
tissue and can make them more prone to lower respiratory infections such as bronchitis
#1 - The fuel: Keep it dry!
Wood can seem dry and still
contain plenty of water, up to 50 percent. The moisture in wood makes the fire give off
more smoke. On the other hand, dry wood can provide up to 44 percent more heat. Whether
you buy wood or harvest your own, the following tips will help you be fire-ready:
- Split it. The wood will dry best and burn most efficiently if the pieces are three
and one-half to six inches in diameter.
- Cover it. Protect the wood from rain and weather. Stack it loosely-- in layers of
alternating directions-- to allow plenty of air circulation. Store it at least six
inches off the ground.
- Give it a year. Wood that has been split, dried and stored under cover for at
least one year usually meets the 20 percent moisture content requirement.
#2 - The fuel: Keep it clean!
Dry, untreated wood is legal. Manufactured logs (pressed sawdust or sawdust/wax) are
legal, but be careful to follow the product instructions and to follow the recommendations
in your stove owner's manual. It is against tribal law, and poses serious health risks, to
burn any of the following:
- garbage (including diapers)
- plastic or rubber products
- treated wood (including particle or strand board)
- asphalt-based or waste petroleum products
- paints and chemicals
- animal carcasses
- anything else which normally emits dense smoke or obnoxious odors.
#3 - The fire: Give it air!
The right amount of air gives you a hotter fire and more complete combustion. That
translates to more heat from your wood and less smoke and pollution. Here are some cleaner
- Build small, hot fires. Don't add too much fuel at one time.
- Step outside and check the chimney or flue. If you can see smoke, your fire may
need more air.
- Read and follow the stove manufacturer's instructions.
- Don't "bank" the stove full of wood and damper down the air supply. This wastes
wood, produces much air pollution, promotes accumulation of creosote (which requires
more frequent cleaning and can lead to chimney fires), and yields very little heat.
Half-full is adequate; it provides enough air space for efficient combustion.
- Don't damper down too far. Allow enough air to reach the wood. This varies among
models and kinds of stoves.
- Make sure your stove is the right size for your home. Too large a stove will
over-heat your living space. You'll want to damper down. This causes added pollution
and wastes wood.
- Don't burn in moderate temperatures. You'll want to damper down, which causes more
pollution and wastes wood.
- Don't burn when air currents carry your smoke to your neighbor's yard or house.
# 4 - The stove: Certified is cleaner!
The stove you use makes a major difference when it comes to air pollution. Any stove
sold in Washington today (or from 1988 on) must meet certification standards.
Many of us have homes with older stoves, however. Compared to new, properly operated
certified models, uncertified stoves:
- produce approximately five times more pollution than certified models;
- use about a third more wood;
- deposit more creosote in chimneys, making more frequent cleaning
The amount of fine particle pollution generated from uncertified woodstoves is
significantly greater, as shown in the illustration below.
Source: Puget Sound Clean Air Agency
One option is to have your current fireplace retrofitted with a gas insert. If the
costs of gas or a certified new stove are unrealistic however, then it is all the more
important to make sure the gaskets and seals are in good working condition, that the flu
is clean and properly connected and that you are using dry, clean fuel.
If you would like to find out if your stove is certified, you can go on-line and check
the specific manufacturer and model, through this website: