The state board shall establish, by regulation, maximum standards for the degree of unsaturation at a bromine number 30 as established by the American Society for Testing and Materials test D
1159-66, or by an appropriate test determined by the state board, for gasoline sold in the South Coast Air Basin designated by the state board.
The state board, in adopting such regulations, shall give full consideration to climatic conditions and may provide that the maximum standards imposed thereby shall be applicable only during those periods of time which the state board determines necessary in order to carry out the purposes of this division.