Sec 57.  EXEMPTIONS.  An Authorization to Construct or a Permit 
                to Operate shall not be required for:

                A.  Vehicles as defined by the Vehicle Code of the State
                    of California, but not including any article, 
                    machine, equipment or other contrivance mounted on 
                    such vehicle that would otherwise require an 
                    Authorization to Construct under the provisions of
                    these Regulations.

                B.  Vehicles used to transport passengers or freight.

                C.  Equipment utilized exclusively in connection with any
                    structure, which structure is designed for and used 
                    exclusively as a dwelling for not more than 
                    two (2) families.

                D.  The following equipment:

                    1.  Comfort air conditioning or comfort ventilating
                        systems which are not designed to remove air 
                        contaminants generated by or released from specific 
                        units or equipment.

                    2.  Refrigeration units except those used as, or in
                        conjunction with, control equipment.

                    3.  Piston-type internal combustion engines used
                        exclusively for agricultural irrigation.

                    4.  Water cooling towers and water cooling ponds not
                        used for evaporative cooling of process water or 
                        not used for evaporative cooling of water from 
                        barometric jets or from barometric condensers.

                    5.  Equipment used exclusively for steam cleaning.

                    6.  Presses used exclusively for extruding metals,
                        minerals, plastics or wood.

                    7.  Incinerators when used for burning of combustible
                        waste of a single or two family dwelling.

                    8.  Brazing, soldering or welding equipment.

                E.  Space Heaters.

                F.  Equipment used in eating establishments for the
                    purpose of preparing food for human consumption.

                G.  Steam heated by natural gas or LPG, or both.

                H.  Self-propelled mobile construction equipment other
                    than pavement burners.

                I.  The on farm use of implements of husbandry.

                J.  Containers, reservoirs or tanks used exclusively for:

                    1.  Storage of liquefied gases.

                    2.  The storage of fuel oils with a gravity of
                        40 degrees AP1 or lower.

                    3.  The storage of lubricating oils.

                    4.  The storage of gasoline having a capacity of less
                        than 250 gallons.

                K.  Structural changes which cannot change the quality,
                    nature or quantity of air contaminant emissions.

                L.  Identical replacements in whole or in part of any
                    article, machine, equipment or other contrivance.

                M.  Repairs or maintenance not involving structural
                    changes to any article, machine, equipment or other 

                N.  Other sources of minor significance specified by the
                    Air Pollution Control Officer.