Maryland Code, Environment § 2-301

(1) May adopt rules and regulations for the control of air pollution in this State, including testing, monitoring, record keeping, and reporting requirements; and

(2) Shall adopt rules and regulations that establish standards and procedures to be followed whenever pollution of the air reaches an emergency condition.

(1) The residential, commercial, or industrial nature of the area affected;

(2) Zoning;

(3) The nature and source of various kinds of air pollution;

(4) The problems of any commercial or industrial establishment that may be affected by the rule or regulation; and

(5) The environmental conditions, population density, and topography of any area that may be affected by the rule or regulation.