For purposes of this chapter "hazardous materials" shall be defined as any substance or materials in a quantity or form which, in the determination of the fire chief or his authorized representative, poses an unreasonable and imminent risk to the life, health or safety of persons or property or to the ecological balance of the environment, and shall include, but not be limited to, such substances as explosives, radioactive materials, petroleum or petroleum products or gases, poisons, etiologic (biologic) agents, flammables and corrosives. (Ord. 152, 4-11-1989)