Carbon monoxide (CO) is a clear and odourless toxic gas. It does not irritate the eyes or respiratory tract. Odour is therefore an inadequate means for preventing carbon monoxide poisoning.
When a person inhales carbon monoxide, the gas enters their blood and interferes with oxygen intake. This damages tissue and can be extremely dangerous to health.
The effects of carbon monoxide poisoning vary according to the following:
Quantity of carbon monoxide in the air
Length of a person’s exposure to gas
Person’s sensitivity to the effects of carbon monoxide
Person’s state of health
Repeated exposure over time.
Symptoms
It is important to understand that carbon monoxide poisoning can only occur if a person is in the presence of a source of the gas.
In fact, the symptoms of carbon monoxide poisoning are often difficult to recognize because they resemble symptoms of other health problems.
Symptoms diminish or disappear when people are no longer in contact with carbon monoxide (for example, when people leave the area, the area is ventilated, the source of carbon monoxide is shut down or moved).
Symptoms of carbon monoxide poisoning vary according to the intensity of the exposure.
The main symptoms of a light poisoning are:
Headache
Fatigue
Nausea
Vomiting
Symptoms of a moderate poisoning are:
Dizziness
Fatigue
Chest pain
Problems with vision
Difficulty concentrating
Symptoms of a severe poisoning are:
Problems coordinating movement or muscle paralysis, which prevent the person from leaving the premises
Loss of consciousness
What to do when you show symptoms in the presence of a source of carbon monoxide, or when a carbon monoxide alarm goes off
A carbon monoxide alarm is a device that can detect the gas.
If you or someone you’re with shows symptoms of posioning, whether the carbon monoxide alarm goes off or or not:
You need to think first of all about your own safety and the safety of other people present in the same situation as you.
Leave the premises and go outside
Dial 9-1-1 or call the Centre antipoison du Québec (poison control centre) at 1-800-463-5060
Leave the door open when exiting the premises in order to completely ventilate the place
Wait for the authorisation of a firefighter before returning inside even for a few minutes
If you do not have symptoms of poisoning, but your carbon monoxide alarm goes off:
If possible, quickly turn off the fuel supply
Head outside
Call 9-1-1
Leave the door open when leaving the premises to ventilate the area completely
Wait for a firefighter's authorization before returning indoors, even for a few minutes
Do not use your fuel-burning appliances until they have been checked by a qualified person if you suspect a malfunction.
Treatment
It is necessary to consult a physician to treat carbon monoxide poisoning.
Administration of high levels of oxygen is the standard treatment. If the person’s condition is more serious, the physician may prescribe hyperbaric oxygen therapy. For this treatment, the person is placed in a closed chamber in which they receive pressurised oxygen.
Complications
Severe poisoning can cause permanent effects.
The following effects can appear during a period of 2 to 40 days after poisoning, even if treated:
Chronic migraines
Neurological disorders that can cause problems with coordination of movement
Everyone is at risk of being poisoned by carbon monoxide. However, the risk is higher for the following:
People with chronic heart disease, anemia or respiratory problems
People 65 years of age and older
Children less than 2 years of age
People who smoke
Pregnant women and their fetuses. Carbon monoxide poisoning increases the risk of fetal death and developmental disorder
Special conditions
In Québec, carbon monoxide poisoning is a reportable disease.
Cases of carbon monoxide poisoning must be reported to public health authorities by a physician or laboratory. This will enable us to carry out investigations to better protect public health.