For purposes of determining the percentage of ethanol in a gasoline-oxygenate blend for use as a fuel, the volume of ethanol includes the volume of any denaturant (including gasoline) that is added to the extent that these denaturants do not exceed the maximum volume percent specified in the latest standard established by ASTM International, except that no standard shall be less stringent than required by any California state law.
Cal. Bus. & Prof. Code § 13440.5
Standards for Spark-Ignition Fuels
Amended by Stats. 2015, Ch. 591, Sec. 17
Official source: California Legislative Information. Reproduced from public-domain California statutes; confirm against the official source for the current text. Not legal advice.