The Clean Indoor Air Act of Maryland[i] is intended to protect the public and employees from involuntary exposure to environmental tobacco smoke in indoor areas open to the public, indoor places of employment, and certain designated private areas.[ii]  The purpose of the Act is to preserve and improve the health, comfort, and environment of the people of the State by limiting exposure to environmental tobacco smoke.[iii]
Under the laws of Maryland, a person is prohibited from smoking in indoor areas open to the public, indoor place where meetings are open to the public, in government-owned or government-operated means of mass transportation including buses, vans, trains, taxicabs, and limousines as well as in indoor place of employment.[iv]
The rules regulating smoking does not however apply to private homes, residences, unless being used by a person who is licensed to provide day care or child care, and in private vehicles, unless used for public transportation of children, or as part of health care or day care transportation. [v]  Smoking is also allowed in hotel or motel room rented to one or more guests as long as the total percent of hotel or motel rooms being so used does not exceed 25%.[vi] 

Smoking is permitted in ny facility of a manufacturer, importer, wholesaler, or distributor of tobacco products or of any tobacco leaf dealer or processor in which employees of the manufacturer, importer, wholesaler, distributor, or processor work or congregate; or congregate and in research or educational laboratory for the purpose of conducting scientific research into the health effects of tobacco smoke.[vii]

There are also regulations that prohibit environmental tobacco smoke in indoor areas open to the public.[viii]  § 24-508 of the Maryland Health-General Code deals with violations and penalties.  For a first violation, a person shall be issued a written reprimand.  A second violation entails a civil penalty of $ 100 and for each subsequent violation there is a civil penalty not less than $ 250.[ix]

An employer who discharges or discriminates against an employee because that employee has made a complaint, has given information to the Department in accordance with this subtitle, has caused to be instituted or is about to cause to be instituted a proceeding under this subtitle, or has testified or is about to testify in a proceeding under this subtitle, shall be deemed in violation of this subtitle and shall be subject to a civil penalty of at least $ 2,000 but not more than $ 10,000 for each violation.[x]

[i] Md. HEALTH-GENERAL Code Ann. § 24-511

[ii] Md. HEALTH-GENERAL Code Ann. § 24-502

[iii] Md. HEALTH-GENERAL Code Ann. § 24-503

[iv] Md. HEALTH-GENERAL Code Ann. § 24-504

[v] Md. HEALTH-GENERAL Code Ann. § 24-505(1)

[vi] Md. HEALTH-GENERAL Code Ann. § 24-505(2)

[vii] Md. HEALTH-GENERAL Code Ann. § 24-505(4),(5)

[viii] Md. HEALTH-GENERAL Code Ann. § 24-507

[ix] Md. HEALTH-GENERAL Code Ann. § 24-508

[x] Md. HEALTH-GENERAL Code Ann. § 24-508