Carbon Monoxide (CO) is a colorless, odorless, deadly gas that is a byproduct of combustion. It is found in the exhaust of spark ignition engines, onboard your boat that is likely to be your gasoline propulsion engine(s) and your generator. It is important to remember that any flame heat source, such as your alcohol or propane stove, oven, or heater also produce CO. If your boat is diesel powered (diesel engines are non-spark ignition and produce lower levels of CO) it is important to remember that the boat tied up next to you may be a source of CO.
CPSC notice: Since 1992, the U.S. Consumer Product Safety Commission (CPSC) has reminded consumers to check smoke alarms and change batteries when they change their clocks, but in that time, many alarms have lost their effectiveness. This year, CPSC wants to remind consumers to replace smoke alarms every ten years and replace carbon monoxide (CO) alarms every five years. Click here for the link to the notice
The Centers for Disease Control in concert with NIOSH have completed a series of tests and issued reports on the dangers of Carbon Monoxide on boats. Their website is http://www.cdc.gov/niosh/topics/coboating/
The USCG Office of Boating Safety has issued an advisory about the dangers of carbon monoxide. It can be found at: http://www.uscgboating.org/alerts/
The USCG also has posted an educational page about carbon monoxide (Click the foregoing sentence to follow the link to this page.)
The American Boat and Yacht Council, Inc (ABYC) is a non-profit safety standards organization that produces standards and recommended practices for small craft. The ABYC standard A-24 pertains to the installation of carbon monoxide detectors onboard boats. ABYC has also produced an educational technical bulletin on carbon monoxide, TH-22 you can contact ABYC at: www.abycinc.org and you can download the referenced items for a fee from this site.
The National Marine Manufacturers Association (NMMA) publishes pamphlets in a “Know more about it” campaign. The pamphlet on CO can be found at: http://www.nmma.org/certification/publications/brochures.asp
How can I protect others and myself? The NMMA recommends:
Know where and how CO may accumulate in and around your boat
Maintain fresh air circulation throughout the boat at all times
Know where you engine and generator exhaust outlets are located and keep everyone away from these areas
Never sit on the back deck, teak surf, or hang on the swim platform while the engine(s) or generator are running
Never enter areas under swim platforms where exhaust outlets are located unless the area has been properly ventilated
Although CO can be present without the smell of exhaust fumes, if exhaust fumes are detected on the boat, take immediate action to ventilate these fumes
Treat symptoms of seasickness as possible CO poisoning. Get the person into fresh air immediately. Seek medical attention- unless you’re sure its not CO.
Install and maintain CO detectors as recommended by the manufacturer. Do not obstruct a CO detector by placing objects in front of it.
Follow the checklist provided in this pamphlet
Get a vessel safety check
How does CO accumulate? The NMMA pamphlet indicates:
Inadequately ventilated canvas enclosures
Exhaust gas trapped in enclosed spaces
Blocked exhaust outlets
Another vessel’s exhaust, CO from the boat docked next to you can enter your boat
“Station wagon effect” or back drafting
At slow speeds, while idling, or stopped; Be aware that CO can remain in or around your boat at dangerous levels even if your engine or another boat’s engine is no longer running!
What is the checklist NMMA recommends I follow?
Trip checklist for Carbon Monoxide
Make sure you know where exhaust outlets are located on your vessel
Educate all passengers about the symptoms of CO poisoning and where CO may accumulate
When docked or rafted with another boat, be aware of exhaust emissions from the other boat
Confirm that water flows from the exhaust outlet when the engine(s) and generator are started
Listen for any change in exhaust sound, which could indicate an exhaust component failure
Test the operation of each CO detector by pressing the test button
Boater’s monthly maintenance checklist
Make sure all exhaust clamps are in place and secure
Look for exhaust leaking from exhaust components. Signs include rust and/or black streaking, water leaks, or corroded or cracked fittings
Inspect rubber exhaust hoses for burned, cracked, or deteriorated sections. All rubber hoses should be pliable and free of kinks.
Annual checklist, Have a qualified marine technician:
Replace exhaust hoses if cracking, charring, or deterioration is found
Ensure that your engine(s) and generator are properly tuned, and well maintained
Inspect each water pump impeller and the water pump housing. Replace if worn. Make sure cooling systems are in working condition
Inspect all metallic exhaust components for cracking, rusting, leaking, or loosening. Check the cylinder head gasket; exhaust manifold, water injection elbow, and the threaded adapter nipple between the manifold and the elbow.
Clean, inspect and confirm proper operation of the generator cooling water anti-siphon valve (if equipped)
How long have Marine CO detectors been available?
Marine CO detectors have been available since the mid 1980’s and have been installed as standard equipment on many brands/models of boats for over five (5) years.
How often should I change my CO detector?
The USCG and the detector manufacturers suggest the detector be replaced every five (5) years or at any time that the unit fails to alarm during testing. They also recommend that a UL listed marine CO detector be installed on all older boats that have a sleeping area.
My detector alarms all the time. Is something wrong with it?
NEVER assume the detector is malfunctioning when it alarms, NEVER disconnect an alarm; Remember CO is a colorless, odorless, deadly gas. Immediately ventilate your boat, remove personnel to fresh air and if anyone is showing symptoms similar to seasickness or intoxication seek immediate medical assistance. As soon as possible have your boat inspected and serviced by a qualified marine technician.
Did NIOSH do any testing relative to CO?
Yes they did. Two NIOSH reports are available: Lake Mead and CO Recboat study both of these reports are Adobe acrobat reader (pdf) files and can be downloaded by clicking on the underlined links.
Did the USCG test Marine CO detectors for reliability?
Yes they did. The report is titled: “A Study of Carbon Monoxide Detector Performance in the Marine Environment”. You can order a copy form the USCG office of Boating Safety for review and comment using the link below.
The document is the result of a boating safety contract to evaluate the reliability of Carbon Monoxide (CO) detectors that, in 2002, were advertised as being suitable for marine environments. The hypothesis was that one or more factors including humidity, salinity, temperature variants, or out-gassing of new boat construction materials, could cause detectors to fail Underwriter Laboratories UL 2034 standard for CO alarms on recreational boats.
Testing indicated that some of the detectors alarmed sooner than required. None of the detectors failed in a manner that presented a safety hazard to the public.
Click the underlined: USCG Office of Boating Safety Articles link to review the complete USCG posting and to order the report.
