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Carbon Monoxide


What is it?
Carbon monoxide (CO) is a colorless, odorless, and poisonous gas.  It is a product of the incomplete burning of hydrocarbon-based fuels.

Where does it come from?
CO comes from non-road engines and vehicles, on-road engines, and nature.  Non-road sources include construction equipment, industrial processes, and boats.  Being a component of motor vehicle exhaust, on-road sources include trucks and cars, especially in heavy traffic.  Natural sources include residential wood burning and forest fires. 

Engines release CO as the result of incomplete combustion of fuel.  Incomplete combustion is most likely to occur at low air-to-fuel ratios in the engine.  These conditions are common during vehicle starting when the air supply is restricted.

How is it harmful?
When emitted at high levels, carbon monoxide is poisonous to all people.  This pollutant enters the bloodstream through the lungs and forms carboxyhemoglobin, a compound that inhibits the blood’s capacity to carry oxygen to organs and tissues. Some of the health effects may include: 

  • Chest pain
  • Cardiovascular problems
  • Vision problems
  • Reduced ability to work or learn
  • Reduced manual dexterity
  • Death  

Along with these dangerous health effects, CO also contributes to the formation of ground level ozone. 

What’s being done to help?
The Environmental Protection Agency (EPA) currently has a one-hour and eight-hour primary standard for carbon monoxide set at 35 parts per million (ppm) and 9 ppm, respectively, which is not to be exceeded more than once per year.  These standards are subject to change as updated scientific information is obtained on the effects of this pollutant on human health.

Regional Matters:
There are various programs in place to help decrease the concentration of CO throughout North Central Texas.  Some include clean fuel programs and new vehicle technologies that have and continue to reduce CO emissions in our region:

The ten-county region of North Central Texas currently falls within the one- and eight-hour concentration limits set by the EPA.  Texas has never exceeded the one-hour standard for CO.  There are currently two CO monitors in the region.  

4/27/2018 JPL/CH %Trans

 North Central Texas Council of Governments | 616 Six Flags Drive P.O. Box 5888 Arlington, TX 76005-5888
 Main Operator: (817) 640-3300 | Fax: (817) 640-7806