# Public Safety (GPS)

## Title 12. Building and Material Codes; Other Safety Provisions

### Subtitle 11. Carbon Monoxide Alarms

#### Section 12-1101

(a) In this subtitle the following words have the meanings indicated.

(b) "Carbon monoxide alarm" means a device that:

  (1) senses carbon monoxide;

  (2) when sensing carbon monoxide, is capable of emitting a distinct and audible sound;

  (3) is listed and carries the listing of a nationally recognized testing laboratory approved by the Office of the State Fire Marshal; and

  (4)

    (i) is wired into an alternating current (AC) powerline with secondary battery backup; or

    (ii) for a hotel, a lodging or rooming house, or a rental dwelling unit:

      (1) is wired into an alternating current (AC) powerline with secondary battery backup;

      (2) is battery-powered, sealed, tamper resistant, and using a long-life battery that has a life of not less than 10 years; or

      (3) is connected to an on-site control unit that monitors the carbon monoxide alarm remotely so that a responsible party is alerted when the device activates the alarm signal and receives its primary power from a battery or the control unit.

(c)

  (1) "Dwelling" means a building or part of a building that provides living or sleeping facilities for one or more individuals.

  (2) "Dwelling" includes a one or two family dwelling, multifamily dwelling, hotel, lodging or rooming house, or dormitory.

(d) "Hotel" has the meaning stated in Sec. 9-201 of this article.

(e) "Install" means to attach to the wall or ceiling of a dwelling in accordance with:

  (1) the National Fire Protection Association (NFPA) 720 standard for the installation of carbon monoxide warning equipment in dwelling units; and

  (2) the manufacturer's recommendations.

(f) "Lodging or rooming house" has the meaning stated in Sec. 9-201 of this article.

(g) "Rental dwelling unit" has the meaning stated in Sec. 6-801 of the Environment Article.

(h) "Sleeping area" has the meaning stated in Sec. 9-101 of this article.

#### Section 12-1102

This subtitle only applies to: 

(1) a dwelling that:

  (i) relies on the combustion of a fossil fuel for heat, ventilation, hot water, or clothes dryer operation; and

  (ii) is a newly constructed dwelling for which a building permit is issued on or after January 1, 2008; or

(2) a hotel, a lodging or rooming house, or a rental dwelling unit.

#### Section 12-1103

A carbon monoxide alarm may be combined with a smoke alarm if the combined device complies with:

(1) this subtitle;

(2) Title 9 of this article; and

(3) American National Standards Institute (ANSI)/Underwriters Laboratories (UL) standards 217 and 2034 or ANSI/UL 268 and 2075.

#### Section 12-1104

(a) Except as provided in subsections (b) and (c) of this section, there must be a carbon monoxide alarm installed in a central location outside of each sleeping area within a dwelling subject to this subtitle.

(b) For a hotel or a lodging or rooming house, on or after April 1, 2017, there must be a carbon monoxide alarm installed within the dwelling, as follows:

  (1) on the wall inside each guest room that:

    (i) contains a device that emits carbon monoxide;

    (ii) is adjacent to a room or area that contains a device that emits carbon monoxide;

    (iii) is adjacent to an enclosed unventilated attached garage; or

    (iv) is connected by ductwork to an enclosed unventilated attached garage or room or area that contains a device that emits carbon monoxide; and

  (2) on a wall in each room or area that:

    (i) contains a device that emits carbon monoxide;

    (ii) is adjacent to a room or area that contains a device that emits carbon monoxide; or

    (iii) is adjacent to an enclosed unventilated attached garage.

(c) For a rental dwelling unit, on or after April 1, 2018, there must be a carbon monoxide alarm installed within the dwelling as follows:

  (1) outside and in the immediate vicinity of each separate sleeping area; and

  (2) on every level of the unit, including the basement.

(d) Notwithstanding subsections (a), (b), and (c) of this section, if there is a centralized alarm system that is capable of emitting a distinct and audible sound to warn all occupants, the owner of a dwelling may install a carbon monoxide alarm within 25 feet of any carbon monoxide-producing fixture and equipment.

#### Section 12-1105

Except as part of routine maintenance, a person may not render a carbon monoxide alarm inoperable.

#### Section 12-1106

This subtitle does not prevent a county or municipal corporation from enacting more stringent laws that relate to carbon monoxide alarms.

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Md. Code Ann., Pub. Safety (as displayed at mgaleg.maryland.gov, October 16, 2026)