Md. Code, Public Safety § 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 § 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 § 9–201 of this article.

(g) “Rental dwelling unit” has the meaning stated in § 6–801 of the Environment Article.

(h) “Sleeping area” has the meaning stated in § 9–101 of this article.