Carbon Monoxide (CO) Incidents Information and Resources

What is Carbon Monoxide (CO)?

Carbon monoxide is a potentially deadly gas produced any time a carbon-based fuel, such as gasoline, propane, charcoal, or oil, burns. Sources on a boat include gasoline engines, generators, cooking ranges, and space and water heaters. Cold or poorly-tuned engines produce more carbon monoxide than warm, properly-tuned engines. Carbon monoxide is colorless, odorless, and tasteless, and mixes evenly with the air.

What is a CO incident as it applies to boating?

Each year, boaters are injured or killed by exposure to carbon monoxide. Most incidents occur on older boats and within the cabin or other enclosed areas. Exhaust leaks, the leading cause of death by carbon monoxide, can allow carbon monoxide to migrate throughout the boat and into enclosed areas. New areas of concern are the rear deck near the swim platform with the generator or engines running; teak surfing or dragging behind a slow-moving boat; and backdraft effect on many vessel types. Regular maintenance and proper boat operation can reduce the risk of injury from carbon monoxide.

For more information, see Carbon Monoxide Danger Brochure, a resource of the National Safe Boating Council

What does CO do to the human body?

Carbon monoxide is absorbed by the lungs and reacts with blood hemoglobin to form carboxyhemoglobin, which reduces the oxygen carrying capacity of the blood. The result is a lack of oxygen for the tissues with the subsequent tissue death and, if exposure is prolonged, death of the individual. Altitude, age, alcohol consumption, and certain health problems will increase the effects of carbon monoxide on an individual. Physical exertion accelerates the rate at which the blood absorbs carbon monoxide.

Human symptoms of a CO incident:

Watery/itchy eyes Loss of physical coordination Nausea
Flushed appearance Ringing in the ears Dizziness
Throbbing temples Tightness across the chest Fatigue
Inattentiveness Headache Collapse
Inability to think coherently Incoherence Convulsions
Slurred speech Red or pink skin

Applicable standard for CO incident prevention

  • ABYC Standard A-24: Installation of Carbon Monoxide Detectors and Alarms (July 2020)

With appreciation to The American Boat & Yacht Council (ABYC) and the National Safe Boating Council for supplying source material for this summary.


--NEW! NASBLA ERAC release: Carbon Monoxide Detection Systems on Recreational Watercraft: Legislative Considerations for the State Boating Law Administrator (September 2019; PDF) developed as general guidance for BLAs addressing marine CO detection-related legislative proposals

--Recent NASBLA ERAC release: Carbon Monoxide Incident Response and Investigation Checklist (August 2018; PDF / Word) developed to assist officers, investigators, and other first responders in the accurate recognition and reporting of CO incidents

--Other NASBLA policy products

--The American Boat & Yacht Council

  • ABYC Standard A-24: Installation of Carbon Monoxide Detectors and Alarms (July 2020)
  • ABYC TH-22: Educational Information About Carbon Monoxide, July 2022

--National Safe Boating Council

--U.S. Coast Guard Boating Safety Division

--CDC The National Institute for Occupational Safety and Health (NIOSH)

Go to the Lighthouse Library for more CO resources (under construction)

page last updated February 28, 2024

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