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Carbon Monoxide (CO)

A colorless, odorless gas that is formed from incomplete fossil fuel combustion or when something is burned incompletely. CO is toxic to all humans and animals, and is the most commonly inhaled poisonous substance.

How is it generated?

Carbon Monoxide is predominately generated from automobiles idling in closed areas. Other sources include: gas appliances (furnaces, stoves and dryers), fireplaces that are blocked, charcoal grills used as inside heaters and smoking.

What Are The Health Effects?

CO affects the central nervous system (CNS) in both humans and animals by inhibiting the uptake of oxygen by the body. Oxygen is normally absorbed into the bloodstream by binding to an oxygen carrier (hemoglobin). When CO enters the body, the oxygen carrier wants to carry CO rather than oxygen (in fact CO is absorbed 240 times more readily than oxygen by hemoglobin).

Provincial Guidelines:

What Can We Do?

Due to the nature of human generated CO, there are a number of things we can all do to minimize CO in the atmosphere:

  1. Reduce the amount of idling of vehicles (warming up time, and use of car starters)
  2. Use alternative transportation (walk, bike, car pool or use public transportation)
  3. Use oxygenated gasolines (Ethanol blended gasolines)
  4. Set your home furnace to a lower temperature, wear sweaters during the winter
  5. Reduce any drafts in home, or building, during winter months
  6. Utilize “Green Power” (eg: wind generated and solar)
  7. Promote use of hydrogen fuel cell technology, solar powered vehicles, and electrical powered vehicles.

Table of Human Symptoms and Other Effects

Occupational Health and Safety Act (Alberta – AR 393/88 Chemical Hazards Regulation)

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


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