Carbon Monoxide Chart

Does anyone have a good listing of CO amounts and their dangers at different levels. I found a heater putting out 125 ppm yesterday and the seller just wanted to argue with me. I still have a headache and would like to have a handout for this situation when it occurs again. Thanks in advance.


Can’t vouch for accuracy:

Get this , There are several different standards depending on organization.

Fed EPA Standard for air quality 1979 Clean air act:
Max exposure levels @ 9ppm for eight hours of exposures and 35ppm for one hour of exposure!

50ppm for eight hours and 200ppm for no more than 15 minutes!

American National Standards Institute, The American Gas Association and the Canadian Gas Association have different standards for flue gas emissions from specific types of appliances.

(This is from:

I would go with the EPA and check for some more info , print them suckers out and hand it to the client/ seller for safety sake since all WILL die in the house if not dealt with.

Plus to me this is an indication of a faulty install or confined room to small to supply combustion air / dilution air for the appliances like the FAU and water heater Kitchen stove.:shock:

Rick, You did not say where you took your readings from - exhaust ports, draft hood, vent connector, registers. Was the CO spilling from the furnace or what was venting outside. Another consideration is whether your measurement was “air-free” or not.

This was a ventless heater in the basmt rec room. I had a head ache all day yesterday and all day today. This afternoon I call my doctor and he said to wait till morning and if I still had a head ache to go to the emergency room and that I need to take some oxygen. I guess morning will tell.

I think you just found out why “ventless” heaters are no longer allowed…