Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Carbon Monoxide and Health Effects

Exposure to Carbon Monoxide - CO and health effects.

Carbon monoxide - CO - is an odorless, tasteless, colorless and toxic gas.

Carbon Monoxide poisoning symptoms

Low to moderate poisoning

  • headache
  • fatigue
  • shortness of breath
  • nausea
  • dizziness

Severe poisoning

  • confusion
  • vomiting
  • loss of muscle coordination
  • unconsciousness

Carbon monoxide is a by-product from combustion processes. Any combustion process, fuel burning appliance, vehicle or other device has the potential to produce toxic carbon monoxide gas.

Carbon monoxide is dangerous because it inhibits the blood's ability to carry oxygen to vital organs such as the heart and brain. Inhaled CO will combine with the oxygen carrying hemoglobin in the blood and will form carboxyhemoglobin (COHb) which is not usable for oxygen transport.

Health effects of Carbon Monoxide

CO - Carbon Monoxide - Health Effects
CO Concentration
0.5 600 1000 2000
1 200 600 1600
2 100 300 1000
4 50 150 400
6 25 120 200
8 252) 100 150

1) ppm - parts per million - is defined as the mass of the component in solution divided by the total mass of the solution multiplied by 106 (one million)

2) The maximum exposure allowed by OSHA in the workplace over an eight hour period is 35 ppm.

3) Typical sickness symptoms are mild headache, fatigue, nausea and dizziness.

4) A CO concentration of 12-13000 ppm is deadly after 1-3 minutes. A CO concentration of 1600 ppm is deadly after one hour.

Carbon monoxide - dangerous health effects vs exposure time diagram

CO - Carbon Monoxide - Toxic Symptoms
Concentration of
CO in air
Inhalation TimeToxic Symptoms
9 Short term exposure ASHRAE recommended maximum allowable concentration in living area.
35 8 hours The maximum exposure allowed by OSHA in the workplace over an eight hour period.
200 2-3 hours Slight headache, tiredness, fatigue, nausea and dizziness.
400 1-2 hours Serious headache-other symptoms intensify.
Life threatening after 3 hours.
800 45 minutes Dizziness, nausea and convulsions.
Unconscious within 2 hours.
Death after 2-3 hours.
1600 20 minutes Headache, dizziness and nausea.
Death within 1 hour.
3200 5-10 minutes Headache, dizziness, nausea.
Death within 1 hour.
6400 1-2 minutes Headache, dizziness, nausea.
Death within 25-30 minutes.
12800 1-3 minutes Death within 1-3 minutes

Related Topics

  • Environment

    Climate, meteorology, solar, wind, emissions and environmental related engineering resources.
  • Physiology

    Human physiology vs. air quality, comfort temperatures, activity and metabolic rates. Health effects of gases adn polutions like carbon monoxide and more.
  • Ventilation Systems

    Design of systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more.

Related Documents


Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .


This page can be cited as

  • The Engineering ToolBox (2005). Carbon Monoxide and Health Effects. [online] Available at: [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter