Carbon Monoxide is serious and should be respected for what it is, the information below was copied and posted here as relevant information for those concerned. See lower for British Columbia Building Code 2018 references:
Carbon Monoxide Poisoning: Health Effects (AEN-166)
ISU Extension Publication #: AEN-166
Author: Dr. Thomas Greiner, Dept. of Agricultural and Biosystems Engineering
Iowa State University
What is carbon monoxide?
Carbon monoxide (CO) is a colorless, odorless, tasteless, deadly gas. You can’t see, smell or taste it. Carbon monoxide is slightly lighter than air and quickly spreads throughout an entire house.
What produces carbon monoxide?
Carbon monoxide gas is produced when fossil fuel burns incompletely because of insufficient oxygen. During incomplete combustion, the carbon and hydrogen combine to form carbon dioxide, water, heat, and deadly carbon monoxide. In properly installed and maintained appliances gas burns clean and produces only small amounts of carbon monoxide. Anything which disrupts the burning process or results in a shortage of oxygen can increase carbon monoxide production. Wood, coal, and charcoal fires always produce carbon monoxide, as do gasoline engines.
What are the symptoms of carbon monoxide poisoning?
Carbon monoxide symptoms mimic the flu: headaches, fatigue, nausea, dizziness, confusion, and irritability. Continued exposure can lead to vomiting, loss of consciousness, brain damage, heart irregularity, breathing difficulties, muscle weakness, abortions and even death. Because the symptoms mimic so many illnesses, it is often misdiagnosed.
Why is carbon monoxide so dangerous?
When CO is inhaled, it bonds with hemoglobin, displacing oxygen and forming carboxyhemoglobin (COHb) resulting in a lack of oxygen to the body cells. The attraction of CO and hemoglobin is approximately 250 times greater than the attraction between oxygen and hemoglobin. The brain and heart require large amounts of oxygen and quickly suffer from any oxygen shortage. This makes even small amounts of carbon monoxide dangerous. Physical, non-reversible damage can occur.
How much is dangerous?
High concentrations of carbon monoxide kill in less than five minutes. At low concentrations it will require a longer period of time to affect the body. Exceeding the EPA concentration of 9 ppm for more than 8 hours is suspected to produce adverse health affects in persons at risk. The U.S. Occupational Health and Safety limit for healthy workers is 50 ppm. Carbon monoxide detectors, which are designed to protect against high concentration of carbon monoxide are required to sound an alarm when concentrations are greater than 100 ppm. (NOTE ADDED BY COMPLETECHIMNEYSWEEP: In Canada many CO detectors are activated at 50ppm) Continued exposure to carbon monoxide can cause permanent brain, nerve, or heart damage. Some people require years to recover while others might never fully recover.
What factors determine the danger level?
The time of exposure, the concentration of CO, the activity level of the person breathing the CO, and the person’s age, sex, and general health all affect the danger level. For instance, a concentration of 400 ppm will cause headaches in 1 to 2 hours. In 3 to 5 hours the same concentration can lead to unconsciousness and death. Physical exertion, with an accompanying increase in respiration rate, shortens the time to critical levels by 2 or 3 fold.
Since 50 ppm is the Occupation Health and Safety limit, is it safe for all people?
No. Respiratory capacity decreases and the risk of heart attack increases at levels well below 50 ppm. The EPA level of 9 ppm appears to be a reasonable limit in homes.
When should CO poisoning be suspected?
Some clues for a family include:
- Entire family is sick at the same time.
- Flu-like symptoms decrease while away from the house.
- Illness is present when gas appliances are in use.
- Excess moisture on the interior of windows.
What should be done for someone who suffers from CO poisoning?
They should immediately be moved into fresh air and medical authorities consulted. Treatment depends on the amount of carbon monoxide in the bloodstream and assessment of the patient. Often oxygen is administered. In severe cases, patients are treated in a hyperbaric chamber. This is a pressurized oxygen chamber. The combination of oxygen and elevated pressure quickly and thoroughly forces carbon monoxide from the body.
Won’t the carbon monoxide leave the body naturally?
The half-life of carboxyhemoglobin in fresh air is approximately 4 hours. To completely flush the carbon monoxide from the body requires several hours, valuable time when additional damage can occur. Medical treatment, using oxygen or hyperbaric chambers, can reduce CO damage, speed recovery, and reduce medical problems.
After CO exposure how long do the effects last?
When people lose consciousness due to carbon monoxide poisoning, they will typically have relapses for several weeks. They will suffer from headache, fatigue, loss of memory, difficulty in thinking clearly, irrational behavior, and irritability. Recover can be slow and frustrating. Some individuals suffer permanent brain and organ damage. Victims may be highly sensitive to CO for the rest of their lives.
Can I be tested for carbon monoxide?
Yes. If you have recently been exposed, a breath test can determine carbon monoxide levels. Medical laboratories can measure carboxyhemoglobin levels in the blood. Carboxyhemoglogin levels in the blood drop after the victim is removed from the carbon monoxide source. For this reason, carboxyhemoglobin tests should not be used as the only indicator of the danger of exposure or the possible adverse health effects. Neurological assessment tests, which ask the patient to perform a variety of physical and mental skills, can be used to determine the effects of CO exposure. Because the effects of carbon monoxide may last for months, lack of elevated carboxyhemoglobin levels in the blood does not insure that carbon monoxide is not the cause of health problems. Consult hyperbaric chamber medical staff who are experienced in carbon monoxide poisoning diagnosis for interpretation of results.
What should I do to protect myself from the dangers of carbon monoxide poisoning?
First, purchase a carbon monoxide detector(s). Second, have all heating appliances checked every year by a qualified heating contractor. And third, replace heating units with direct-vent sealed combustion units.
This is taken directly from the BC Building Code 2018:
6.9.3. Carbon Monoxide Alarms
126.96.36.199. Carbon Monoxide Alarms
1) This Article applies to every building that contains an assembly occupancy, a care occupancy with individual
suites or containing sleeping rooms or bed spaces not within a suite, a residential occupancy, a business and personal
services occupancy, or a mercantile occupancy, and that
a) is served by or contains a fuel-burning appliance, or
b) contains a storage garage.
2) Carbon monoxide (CO) alarms installed in a residential occupancy or a care occupancy as required by this
a) conform to CAN/CSA-6.19, “Residential Carbon Monoxide Alarming Devices,”
b) be equipped with an integral alarm that satisfies the audibility requirements of CAN/CSA-6.19, “Residential
Carbon Monoxide Alarming Devices,”
c) have no disconnect switch between the overcurrent device and the CO alarm, where the CO alarm is
powered by the electrical system serving the suite (see Note A-188.8.131.52.(2)(c)), and
d) be installed as recommended by the manufacturer.
3) Except as permitted by Sentence (9), where a fuel-burning appliance is installed in a suite of residential
occupancy or in a suite of care occupancy, a CO alarm shall be installed
a) inside each sleeping room or bed space, or
b) outside each sleeping room or bed space, within 5 m of each door serving a sleeping room or bed space,
measured following corridors and doorways.
4) Except as permitted by Sentence (9), where a fuel-burning appliance serves a residential occupancy or a care
occupancy and is installed in a service room that is not in a suite of residential occupancy nor in a suite of care occupancy,
a CO alarm shall be installed
a) either inside each sleeping room or bed space, or if outside, within 5 m of each door serving a sleeping room
or bed space, measured following corridors and doorways, in every suite of residential occupancy or suite of care
occupancy that shares a wall or floor/ceiling assembly with the service room, and
b) in the service room.
5) Except as permitted by Sentence (9), for each suite of residential occupancy or suite of care occupancy that shares
a wall or floor/ceiling assembly with a storage garage or that is adjacent to an attic or crawl space to which the storage
garage is also adjacent, a CO alarm shall be installed
a) inside each sleeping room or bed space, or
b) outside each sleeping room or bed space, within 5 m of each bedroom door serving a sleeping room or bed
space, measured following corridors and doorways.
6) CO alarms installed in an assembly occupancy, a business and personal services occupancy, or a mercantile
occupancy as required by this Article shall conform to
a) CAN/CSA-6.19, “Residential Carbon Monoxide Alarming Devices,” notwithstanding the scope of
b) UL 2034, “Standard for Single and Multiple Station Carbon Monoxide Alarms,” notwithstanding the scope
of that standard, or
c) good engineering practice.
(See Note A-184.108.40.206.(6).)
7) Except as permitted by Sentence (9), where a fuel-burning appliance serves an assembly occupancy, business and
personal services occupancy, or mercantile occupancy, a CO alarm shall be,
a) where the fuel-burning appliance is part of a system that could circulate or distribute CO to a suite of assembly
occupancy, business and personal services occupancy or mercantile occupancy, installed
i) on each storey of each suite that may be exposed, and
Division B: Acceptable Solutions Part 6 – Heating, Ventilating and Air-conditioning
British Columbia Building Code 2018 Revision 2.01 Division B
ii) in a suite containing an assembly major occupancy, each classroom and dedicated gathering room or space,
b) installed in the room or space in which the fuel-burning appliance is located. (Bold and Italic added)
(See Note A-220.127.116.11.(7).)
8) Except as permitted by Sentence (9), for each suite of assembly occupancy, business and personal services
occupancy, or mercantile occupancy that shares a wall or floor/ceiling assembly with either a storage garage or a service
room containing a fuel-burning appliance, or that is adjacent to either an attic or crawl space to which the storage
garage or a service room containing a fuel-burning appliance is also adjacent, a CO alarm shall be installed
a) on each storey of the adjacent suite,
b) where the adjacent suite contains an assembly major occupancy, each classroom and dedicated room or space,
c) in each service room containing a fuel-burning appliance.
(See Note A-18.104.22.168.(8).)
9) CO detectors are permitted to be installed in lieu of CO alarms required by this Article provided the
a) sound audible signals within the location they serve, as described in Sentences (3) to (5), (7) and (8),
b) are installed in conformance with CAN/ULC-S524, “Installation of Fire Alarm Systems,” and
c) form part of the fire alarm system.