WCAS/monitoring/CO
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.
Currently there are no Alberta Guidelines for carbon monoxide; however, Environment Canada's guidelines for ambient air are:
| 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 |