(a) Except as provided in divisions (b) and (c) below, it shall be unlawful for any person, firm, corporation or other entity to park any vehicle, trailer or semi-trailer carrying any hazardous material within any city zoning districts as defined in Chapter XVI of this code.
(b) Division (a) above shall not apply to vehicles, trailers or semi-trailers parked for continuous periods of time not to exceed one hour where such vehicles, trailers or semi-trailers are parked along those routes specified in § 14-404 of this code.
(c) Division (a) above shall not apply to any vehicle, trailer or semi-trailer carrying any hazardous material where such vehicle, trailer or semi-trailer is not parked within 500 feet of any structure used for human habitation.