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Article: Carbon Monoxide – “Silent Killer”

Carbon Monoxide – “Silent Killer”

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  1. Carbon Monoxide – “Silent Killer”

Carbon Monoxide – “Silent Killer”

As we get into the cooler times of the year, thoughts turn to keeping warm and dry and providing light for shorter days.    We tend to use devices that burn something to provide heat and light as a response.  One of the by-products of burning, or combustion, happens to be Carbon Monoxide  (CO).  The NFPA reported that in 2010, there were 81,000 fire department responses that involve CO issues in the US alone (Note 1).   

Although anyone can be susceptible to inhaled CO poisoning, the unborn, young children, the elderly, those with respiratory illnesses, heart disease, or anemia (low red blood cell counts) can be especially at risk.  CO works by attaching to the red blood cells which transport oxygen around the body.  CO  attaches 210 times more readily (Note 2) to red blood cell hemoglobin  than Oxygen and it effectively “crowds out” this key life compound.  Further, CO remains attached to the red blood cells for longer periods, with a half-life of 5 hours once the individual is exposed to fresh air.  Thus amounts in the blood can become cumulative after repeated exposure during a short time.  Length of exposure(s) and concentration of CO in the inhaled air are factors in how deadly the timetable will be.

The reason Carbon Monoxide is commonly referred to as the deadly killer is that it has no smell, taste or visual appearance. Further, symptoms can include mental confusion, and tiredness, making it more difficult to recognize.  Initial symptoms may be flu-like.  The most common symptoms are headache, nausea and vomiting, dizziness, lethargy and a feeling of weakness. Infants may be irritable and feed poorly. Neurological signs include confusion, disorientation, visual disturbance, syncope and seizures (Note 3).


Things that produce CO in closed spaces can include gas/oil/woods furnaces, stoves, boilers, heaters, water heaters, engines, generators, cars, trucks, motors, grills, gas lanterns, fireplaces and anything that burns something to produce normal positive results.  Electric heaters generally don’t produce CO, but if a generator is inside the house powering the heater, that would be a problem. 

It is normal to have gas appliances or woodstoves or fireplaces in a home, and these are usually installed with a venting system. Sometimes vents are incorrectly installed or can become blocked.  A common blockage may be squirrel or bird nests in a chimney.  

A couple of things that will reduce risks are:

1.       Use generators outside only.  Run cars out of doors – don’t warm up a car in the garage by running the engine.  Use charcoal grills outside only. Fireplace flus should be checked annually before the burning season and flue cap screens will keep birds and animals from building nests and blocking proper venting.

2.       If you burn wood in a fireplace or stove, use hard woods that don’t rapidly build up soot in the flue.  Pine and wood that already contain creosote are not good choices.

3.       Carbon Dioxide Detectors have come down in cost and rarely provide a false alarm.   Some usefully guidelines can be found here:

Public Education: 


  Note1: NFPA website:  (Use link above).

 Note 2: Blumenthal, Ivan (1 June 2001). "Carbon monoxide poisoning". J R Soc Med (The Royal Society of Medicine) 94 (6): 270–272. PMC 1281520. PMID 11387414

 Note 3: Carbon monoxide poisoning. Early awareness and intervention can save lives. Tomaszewski C, Postgrad Med. 1999 Jan; 105(1):39-40, 43-8, 50.




Copyright 2018  AGIS Network, Inc. 

Last Updated on 4/12/2018