If any section, subsection, part, clause or phrase in subdivisions (12) and (15) of subsection (a) of § 12-407 and § 12-432a is for any reason held to be invalid or unconstitutional, any section, subsection, part, clause or phrase in said subdivisions (12) and (15) of subsection (a) of § 12-407 and § 12-432a not held to be invalid or unconstitutional shall not be affected and shall remain in full force and effect.