Home Inspector Provides Information on Carbon Monoxide

As the weather gets colder people are beginning to use furnaces and wood stoves more. As this happens every year a carbon monoxide death will eventually occur. I want to give information and tips to help prevent this from occurring.

First some information on carbon monoxide. It is a colorless, tasteless, odorless gas and this makes it difficult to detect without a CO detector. So get a detector if you do not have one already. The concentration of CO in the air is directly related to the severity of the effects.

General information on CO levels

35 ppm (0.0035%) Headache and dizziness within six to eight hours of constant exposure

100 ppm (0.01%) Slight headache in two to three hours

200 ppm (0.02%) Slight headache within two to three hours; loss of judgment

400 ppm (0.04%) Frontal headache within one to two hours

800 ppm (0.08%) Dizziness, nausea, and convulsions within 45 min; insensible within 2 hours

1,600 ppm (0.16%) Headache, tachycardia, dizziness, and nausea within 20 min; death in less than 2 hours

3,200 ppm (0.32%) Headache, dizziness and nausea in five to ten minutes. Death within 30 minutes.

6,400 ppm (0.64%) Headache and dizziness in one to two minutes. Convulsions, respiratory arrest, and death in less than 20 minutes.

12,800 ppm (1.28%) Unconsciousness after 2-3 breaths. Death in less than three minutes.

As you can read the results can be tragic. When exhaust vents have a poor slope the exhaust gases do not vent to the exterior as well as they should and this can result in higher CO levels in the home. Even with a correctly sloped exhaust flues every home should have a carbon monoxide detector if the home has even one gas burning appliance. It is also a good idea to have older gas burning appliances checked to determine that the heat exchanger is not cracked.

Exhaust from potential sources of carbon monoxide should not terminate near an air intake or a window. Gasoline powered generators/engines produce CO and should be operated with care as to where the exhaust goes.

A recent home inspection of a home that had a poorly sloped gas water heater flue verified that the home did have elevated levels of CO. The buyer was informed of the presence of elevated CO and the listing agent was also informed so that the seller of the home can be informed. High levels of CO do occur so please check your appliances and have a CO detector in your home. You do not need to wait for a home inspection to check CO levels in your home. Detectors that plug into a wall outlet or installed like smoke detectors are easily available at a home improvement stores.