Safety and health newsletter for the Oregon construction industry


August 14, 2012

Carbon monoxide danger

Carbon monoxide and small gas powered engines

Although carbon monoxide’s reputation as a silent killer is well known, it continues to find unsuspecting victims at worksites in Oregon.

In July, construction workers operating a gas-powered saw and other internal combustion engine equipment in a warehouse were overcome by carbon monoxide despite the employer’s effort to keep air moving with commercial fans. Then, in an incident at another site, a construction worker using a gas-powered saw in a manhole was overcome by carbon monoxide and lost consciousness. And in a third incident, several workers became ill after an employee began using a gas-powered pressure washer to clean a refrigerated room at a fruit processing plant.

Too many people don’t know that small gas-powered engines produce copious quantities of carbon monoxide, which – as these incidents show – can have deadly consequences when they’re operated in poorly ventilated areas.

What’s the problem with carbon monoxide?

Carbon monoxide robs oxygen from your blood when it enters your lungs. That means there’s less oxygen for your heart, brain, and other vital organs – and without oxygen, they’ll shut down. Aside from subtle warning signs – headache, fatigue, dizziness, and drowsiness – you won’t know you’re ill because carbon monoxide is colorless and odorless. Large amounts of carbon monoxide can overcome you without warning, causing you to lose consciousness and suffocate. The National Institute for Occupational Safety and Health (NIOSH) notes that carbon monoxide levels above 1,200 parts per million could cause death or irreversible health effects within 30 minutes, known as “immediately dangerous to life and health.”

What are the risks?

Your risk of becoming a carbon monoxide victim depends on a number of factors, including the concentration of carbon monoxide in the air, how long you’re exposed, and your exertion level. Oregon OSHA doesn’t allow a worker to be exposed to more than 50 parts per million averaged over an eight-hour time period (carbon monoxide is measured in parts per million or “ppm”). But other safety and health organizations have established guidelines at lower exposure levels. For example, the American Conference of Governmental Industrial Hygienists (ACGIH) has assigned carbon monoxide a threshold limit value or “TLV” of 25 ppm for an eight-hour workday.

Those numbers aren’t likely to help, however, you unless you have access to personal air monitoring equipment. If you’re using gas-powered equipment, play it safe and stay away from poorly ventilated areas – even in places that you might consider safe, such as parking garages and warehouses.

Tips for working safely:

  • Know the sources of carbon monoxide poisoning and its symptoms (gasoline, natural gas, oil, propane, coal, and wood all produce carbon monoxide).
  • Keep internal-combustion equipment in good operating condition.
  • Have a procedure to ensure the safety of those who work with internal-combustion equipment in poorly ventilated areas.
  • Test the air regularly in poorly ventilated areas and use mechanical ventilation when possible to keep carbon monoxide levels below safe levels.

For more information, see the NIOSH Workplace Safety & Heath Topic Page, Carbon Monoxide Hazards from Small Gasoline Powered Engines. Also, Oregon OSHA’s Education Section recently produced this YouTube video on carbon monoxide poisoning.


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