­

 

Carbon Monoxide - Part 1

What You Should Know About Combustion Appliances and Indoor Air Pollution

Hazards may be associated with almost all types of appliances. The purpose of this section is to answer some common questions you may have about the potential for one specific type of hazard - indoor air pollution associated with one class of appliances - combustion appliances.

Combustion appliances are those which burn fuels for warmth, cooking, or decorative purposes. Typical fuels are gas, both natural and liquefied petroleum (LP); kerosene; oil; coal; and wood. Examples of the appliances are space heaters, ranges, ovens, stoves, furnaces, fireplaces, water heaters, and clothes dryers. These appliances are usually safe. However, under certain conditions, these appliances can produce combustion pollutants that can damage your health, or even kill you.

Possible Health Effects range from headaches, dizziness, sleepiness, and watery eyes to breathing difficulties or even death. Similar effects may also occur because of common medical problems or other indoor air pollutants. This section was written:

  1. To encourage the proper use, maintenance, and installation of combustion appliances;

  2. To discuss the pollutants produced by these appliances;

  3. To describe how these pollutants can affect your health; and,

  4. To tell you how you can reduce your exposure to them.

  • Should I be concerned about indoor air pollution?

YES. Studies have shown that the air in our homes can be even more polluted than the outdoor air in big cities. Because people spend a lot of time indoors, the quality of the air indoors can affect their health. Infants, young children and the elderly are a group shown to be more susceptible to pollutants. People with chronic respiratory or cardiovascular illness or immune system diseases are also more susceptible than others to pollutants.

Many factors determine whether pollutants in your home will affect your health. They include the presence, use, and condition of pollutant sources, the level of pollutants both indoors and out, the amount of ventilation in your home, and your overall health.

Most homes have more than one source of indoor air pollution. For example, pollutants come from tobacco smoke, building materials, decorating products, home furnishings, and activities such as cooking, heating, cooling, and cleaning. Living in areas with high outdoor levels of pollutants usually results in high indoor levels. Combustion pollutants are one category of indoor air pollutants.

  • What are combustion pollutants?

Combustion pollutants are gases or particles that come from burning materials. The combustion pollutants discussed in this section come from burning fuels in appliances. The common fuels burned in these appliances are natural or LP gas, fuel oil, kerosene, wood, or coal. The types and amounts of pollutants produced depend upon the type of appliance, how well the appliance is installed, maintained, and vented, and the kind of fuel it uses. Some of the common pollutants produced from burning these fuels are carbon monoxide, nitrogen dioxide, particles, and sulfur dioxide. Particles can have hazardous chemicals attached to them. Other pollutants that can be produced by some appliances are unburned hydrocarbons and aldehydes.

Combustion always produces water vapor. Water vapor is not usually considered a pollutant, but it can act as one. It can result in high humidity and wet surfaces. These conditions encourage the growth of biological pollutants such as house dust mites, molds, and bacteria.

  • Where do combustion pollutants come from?

Combustion pollutants found indoors include: outdoor air, tobacco smoke, exhaust from car and lawn mower internal combustion engines, and some hobby activities such as welding, wood-burning, and soldering. Combustion pollutants can also come from vented or unvented combustion appliances. These appliances include space heaters, gas ranges and ovens, furnaces, gas water heaters, gas clothes dryers, wood or coal-burning stoves, and fireplaces. As a group these are called "combustion appliances."

  • What is a vented appliance? What is an unvented appliance?

Vented appliances are appliances designed to be used with a duct, chimney, pipe, or other device that carry the combustion pollutants outside the home. These appliances can release large amounts of pollutants directly into your home, if a vent is not properly installed, or is blocked or leaking.

Unvented appliances do not vent to the outside, so they release combustion pollutants directly into the home.

Look at the table in Figure 134 for typical appliance problems that cause the release of pollutants in your home. Many of these problems are hard for a homeowner to identify. A professional is needed.

Figure 134: Combustion Appliances and Potential Problems

Appliances

Fuel

Typical Potential Problems

Central Furnaces
Room Heaters
Fireplaces

Natural or
Liquefied
Petroleum Gas

Cracked heat exchanger;
Not enough air to burn fuel properly; Defective/blocked flue; Maladjusted burner

Central Furnaces

Oil

Cracked heat exchanger;
Not enough air to burn fuel properly;
Defective/blocked flue; Maladjusted burner

Central Heaters
Room Heaters

Wood

Cracked heat exchanger; Not enough air to burn fuel properly; Defective/blocked flue; Green or treated wood

Central Furnaces
Stoves

Coal

Cracked heat exchanger; Not enough air to burn fuel properly; Defective grate

Room Heaters
Central Heaters

Kerosene

Improper adjustment; Wrong fuel (not-K-1); Wrong wick or wick height; Not enough air to burn fuel properly

Water Heaters

Natural or
Liquefied
Petroleum Gas

Not enough air to burn fuel properly; Defective/blocked flue; Maladjusted burner

Ranges; Ovens

Natural or
Liquefied
Petroleum Gas

Not enough air to burn fuel properly; Maladjusted burner; Misuse as a room heater

Stoves

Fireplaces

Wood
Coal

Not enough air to burn fuel properly; Defective/blocked flue; Green or treated wood; Cracked heat exchanger or firebox

  • Can I use charcoal grills or charcoal hibachis indoors?

No. Never use these appliances inside homes, trailers, truck-caps, or tents. Carbon monoxide from burning and smoldering charcoal can kill you if you use it indoors for cooking or heating. There are about 25 deaths each year from the use of charcoal grills and hibachis indoors.

NEVER burn charcoal inside homes, trailers, tents, or other enclosures. The carbon monoxide can kill you.

  • What are the health effects of combustion pollutants?

The health effects of combustion pollutants range from headaches and breathing difficulties to death. The health effects may show up immediately after exposure or occur after being exposed to the pollutants for a long time. The effects depend upon the type and amount of pollutants and the length of time of exposure to them. They also depend upon several factors related to the exposed person. These include the age and any existing health problems. There are still some questions about the level of pollutants or the period of exposure needed to produce specific health effects. Further studies to better define the release of pollutants from combustion appliances and their health effects are needed.

The sections below discuss health problems associated with some common combustion pollutants. These pollutants include carbon monoxide, nitrogen dioxide, particles, and sulfur dioxide. Even if you are healthy, high levels of carbon monoxide can kill you within a short time. The health effects of the other pollutants are generally more subtle and are more likely to affect susceptible people. It is always a good idea to reduce exposure to combustion pollutants by using and maintaining combustion appliances properly.

Log in to comment
­