As I mentioned on WERU's Common Health show this week, home performance is about a lot more than comfort and energy savings. Those things are important, of course, but they aren't worth a thing if your home isn't safe and healthy.

The biggest health issues we see are poor indoor air quality and unsafe levels of carbon monoxide.  CO is pretty scary stuff, both because it can be lethal and because there's such a lack of understanding about it. (I'm looking at you, folks who unplugged the CO monitor because it wouldn't stop beeping). Let's start at the beginning:

What is carbon monoxide?
CO is an odorless, colorless, toxic gas.
CO makes you sick by preventing your body from absorbing oxygen.
CO accumulates in your body over time, so even low levels can be dangerous.

Where does CO come from?
Anyplace there’s a flame, there’s a chance carbon monoxide (CO) is being produced.  Whether your central heating system, gas stovetop or oven, woodstove, gas hot water heater – these appliances create heat through combustion – and CO is a dangerous by-product of that process.

What are the effects of carbon monoxide?
Symptoms of CO poisoning range from flu-like symptoms – headaches, dizziness, disorientation, nausea, and fatigue – to impaired vision and brain function, to death.  Reactions vary greatly from person to person, but children, pregnant women, and the elderly are at the greatest risk.

When it comes to CO, how much is too much?
Carbon monoxide levels are measured in ppm, or parts per million. Because CO accumulates in your body, health affects vary according to levels and length of exposure as well as the age and health of the person, and it’s hard to say absolutely what is safe. Most research and regulations focus on acute exposure, and everyone agrees that concentrations above 100-200 ppm are immediately dangerous. There’s less consensus about lower CO levels, but some studies show that chronic exposure to levels as low as 5 ppm may cause permanent mental or physical problems.

How can you monitor carbon monoxide levels?
Every home should have carbon monoxide detectors correctly positioned (unobstructed and high) on each floor and in each sleeping area.  Readily available, relatively low-cost, UL-listed CO monitors are designed to alert homeowners to high levels:

  • 30 ppm for up to 30 days
  • 70 ppm for up to 4 hours
  • 150 ppm for up to 50 minutes
  • 400 ppm for up to 15 minutes

These levels are higher than those allowed by OSHA and would even allowyou to breathe air with 358 ppm for 45 minutes without an alarm!

That’s why we recommend low-level CO monitors, which are more precise, expensive instruments designed to protect against chronic, low level CO poisoning. The CO Experts model has six audio/visual alarm levels ranging from 10 ppm to 100 ppm. Recommended actions for each alarm level vary from calling your HVAC service provider to evacuating immediately and calling 911.