***(This article has been re-posted from the MN Department of Health)***
Carbon monoxide (CO) is an odorless, colorless gas formed by the incomplete combustion of fuels. When people are exposed to CO gas, the CO molecules will displace the oxygen in their bodies and lead to poisoning.
The Problem with CO
Since CO has no odor, color or taste, it cannot be detected by our senses. This means that dangerous concentrations of the gas can build up indoors and humans have no way to detect the problem until they become ill. Furthermore, when people become sick the symptoms are similar to the flu, which can cause victims to ignore the early signs of CO poisoning.
The CDC estimates that approximately 400 people die from unintentional CO exposure in the United States every year. Data specific to Minnesota show that an average of 14 people die due to unintentional CO poisoning each year. The same data shows that another 307 people visit emergency department each year for treatment of symptoms linked to unintentional CO exposure. For more data information Carbon Monoxide Data Portal.
The good news is that carbon monoxide poisoning can be prevented with simple actions such installing a CO alarm and maintaining fuel burning appliances.
Carbon Monoxide Sources in the Home
In simple terms, CO is produced whenever a material burns. Homes with fuel-burning appliances or attached garages are more likely to have CO problems Common sources of CO in our homes include fuel-burning appliances and devices such as:
- Clothes dryers
- Water heaters
- Furnaces or boilers
- Fireplaces, both gas and wood burning
- Gas stoves and ovens
- Motor vehicles
- Grills, generators, power tools, lawn equipment
- Wood stoves
- Tobacco smoke
Typical Indoor CO Concentrations
Ideally, the level of CO indoors should be the same as CO concentrations outside. In the Minneapolis/St. Paul metro area, outdoor CO levels typically range from 0.03-2.5 parts per million (ppm) averaged over an 8-hour period. These levels are well below the federal standard of 9 ppm for CO in outdoor air. In general, concentrations are lower in rural areas and higher in urban areas. Finding CO concentrations higher indoors than outdoors indicates a source of CO either inside or very close to your home.
Protecting Your Family from CO Poisoning
1. Properly vent and maintain fuel-burning appliances
It is important to know what appliances in your home are fuel-burning and make sure that they are maintained properly. All of these appliances should be vented to the outside. You should have your fuel-burning appliances (ex. furnace) checked by a qualified heating contractor every year to look for potential problems. It is also a good idea to know the signs of a potential CO problem:
- Streaks of soot around fuel-burning appliances, or fallen soot in a fireplace
- Absence of an upward draft in your chimney
- Excess moisture and condensation on windows, walls and cold surfaces
- Rusting on flue pipes or appliance jacks
- Orange or yellow flame in combustion appliances (the flame should be blue)
- Damaged or discolored bricks at the top of the chimney
Never use appliances intended for outdoor use inside. Examples include barbecue grills, camp stoves, portable generators or gas-powered lawn equipment. Do not use an oven to heat your home. Not only is it a fire risk, it is also a carbon monoxide hazard. Do not run or idle your vehicle in an attached garage. Instead, back your vehicle out right away. Check that your vehicle’s exhaust pipe is not blocked, for example, by snow during the winter.
2. Know the symptoms of CO poisoning
Identifying CO poisoning can be difficult because the symptoms are similar to the flu. CO is often called the “silent killer” because people will ignore early signs and eventually lose consciousness and be unable to escape to safety.
For most people, the first signs of exposure include mild headache and breathlessness with moderate exercise. Continued exposure can lead to more severe headaches, dizziness, fatigue and nausea. Eventually symptoms may progress to confusion, irritability, impaired judgment and coordination, and loss of consciousness.
You can tell the difference between CO poisoning and the flu with these clues:
- You feel better when you are away from home
- Everyone is the home is sick at the same time (the flu virus usually spreads from person to person)
- The family members most effected spend the most time in the house
- Indoor pets appear ill
- You don’t have a fever or body aches, and you don’t have swollen lymph nodes that are common with the flu and some other infections
- Symptoms appear or seem to get worse when using fuel-burning equipment
3. Install and maintain CO alarms in your home
Minnesota state law (MN Statute 299F.50) requires that every home have at least one operational CO alarm within 10 feet of every room legally used for sleeping. All CO alarms should conform to the latest Underwriters Laboratory (UL) Standards. Please follow the manufacturer’s instructions for placement of your CO alarm, and take note of the suggested replacement date.