Carbon Monoxide Exposure


Workers that blow and place insulation may face hazards from carbon monoxide exposure.

Risk Description:

Carbon monoxide (CO) is a poisonous, colorless, odorless, and tasteless gas that can overcome workers without warning. Although it has no detectable odor, CO is often mixed with other gases that do have an odor.  CO results from the incomplete burning of natural gas and any other material containing carbon such as gasoline, kerosene, oil, propane, coal, or wood.  In construction, it is common to find fuel-powered tools and heavy equipment that can lead to the risk of carbon monoxide poisoning, especially in poorly ventilated or confined spaces.
Inhaled CO monoxide displaces oxygen in the blood which deprives vital organs in the body.  Although, CO poisoning can be reversed if caught in time, acute poisoning may still result in permanent damage to the parts of your body that require a lot of oxygen such as the heart and brain. Significant reproductive risk is also linked to CO.
CO symptoms varies between person to person but may occur sooner for those that are most susceptible such as children, elderly people, people with lung or heart disease, people at elevated altitudes, or those who already have elevated CO blood levels (smokers).  Initial symptoms of CO poisoning may include: chest pain (people with angina), chest tightness, dizziness, drowsiness, headache, fatigue, or nausea. Symptoms during prolonged and high exposures include confusion, vomiting, muscle weakness, loss of consciousness, and collapse.

Assessment Info:

Assessing general work conditions and environments can help quickly determine whether workers may be potentially exposed to CO in construction.

  • When working in trenches, are there nearby heavy equipment in operation?
  • Will workers be operating gasoline-powered engines in confined spaces or partially-enclosed areas?
  • Will workers be operating welding equipment in confined spaces or partially-enclosed areas?
  • Where generators or gasoline-powered engines are located outside, are they placed away from air intakes?

Regulations & Standards:


Federal OSHA Standards are enforced by the U.S. Department of Labor in 26 states. There are currently 22 states and jurisdictions operating complete State plans (covering both the private sector and state and local government employees) and 5 - Connecticut, Illinois, New Jersey, New York and the Virgin Islands - which cover public employees only. If you are working in one of those states or jurisdictions you should ensure that you are complying with their requirements.