Carbon Monoxide


Carbon monoxide is a colourless, odourless gas emitted into the atmosphere primarily from incomplete combustion of carbon-based fuels such as gasoline, oil and wood.


Natural and human sources of carbon monoxide include burning of vegetation such as forest fires and wildfires, and emissions from vehicles.

Alberta Guidelines

Currently there are no Alberta Guidelines for carbon monoxide; however, Environment Canada's guidelines for ambient air are:

  • 1–hour average of 13 ppm
  • 24–hour average of 5 ppm
Concentration (ppm) Exposure Time Human Symptoms and other Effects
3200 Headache, dizziness and nausea - death within 1 hour
800 Dizziness, nausea and convulsions - unconscious within 2 hours and dead within 2 to 3 hours
400 3 hours Serious headache - other symptoms intensify and life threatening after 3 hours
200 15 minutes Mild headache, fatigue, nausea and dizziness
50 Maximum exposure allowed (OSHA) in the workplace.
25 8 hour limit Maximum exposure in the workplace (Time Weighted Average)
13 1 hour Canada ambient air quality guideline
9 Maximum allowable concentration short term in living area (ASHRAE)
5 24 hour Canada ambient air quality guideline
0 – 1 Normal background levels

Air Quality Data

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Carbon Monoxide (CO) Trends

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