Carbon Monoxide Alarms

Carbon monoxide is an odorless, tasteless, invisible gas. Carbon monoxide poisoning is a serious public health concern. More than 10,000 people are poisoned by carbon monoxide and require medical treatment each year. More than 500 people in the U.S. die annually from carbon monoxide poisoning.


In Maryland, a carbon monoxide alarm is defined as a device that is capable of detecting carbon monoxide. When sensing an unhealthy accumulation of carbon monoxide, the device is capable of emitting a distinct and audible sound that warns the occupants. The device must carry the listing of a nationally recognized testing laboratory approved by the Office of the State Fire Marshal and be hard wired into an alternating current (AC) power line with secondary battery backup.  Read the Law: Maryland Code, Public Safety, Section 12-1101

Does this law apply to me? This law only applies to a dwelling unit that relies on a fossil fuel (e.g., wood, kerosene, gasoline, charcoal, propane, natural gas, and oil) for heat, ventilation, hot water, or clothes dryer operation and is a newly-constructed dwelling with a building permit issued on or after January 1, 2008. Read the Law: Maryland Code, Public Safety, Section 12-1102

Where do I have to install the alarm? A carbon monoxide alarm must be installed in a central location outside of each sleeping area OR, if there is a centralized alarm system capable of emitting a distinct and audible sound to warn all occupants, the carbon monoxide alarm may be installed within 25 feet of any carbon monoxide-producing fixture and equipment. Read the Law: Maryland Code, Public Safety, Section 12-1104

Can I buy a combination smoke and carbon monoxide alarm? Yes, a carbon monoxide alarm may be combined with the smoke alarm if it meets the requirements of Section 12-1103. Read the Law: Maryland Code, Public Safety, Section 12-1103

Can I paint over the alarm or otherwise mess with it? No. Except as part of routine maintenance, a person may not render a carbon monoxide alarm inoperable. Read the Law: Maryland Code, Public Safety, Section 12-1105

Do other laws apply to me? Your local county or municipal corporation may enact more stringent laws that relate to carbon monoxide alarms. You should always check with your specific county to see if they have additional requirements that affect you. Read the Law: Maryland Code, Public Safety, Section 12-1106