Okla. Admin. Code § 710:55-1-2
The following words and terms, when used in this Chapter, shall have the following meaning, unless the context clearly indicates otherwise:
"Ethanol", means "fuel grade ethanol". Also known as ethyl-alcohol or alcohol.
"Farm tractor", for purposes of this Chapter, means all tractor-type, motorized farm implements and equipment, but does not include motor vehicles of the truck-type, pickup truck-type, automobiles, and other motor vehicles required to be registered and licensed under the Oklahoma Vehicle License and Registration Act.[See:68 O.S. § 500.4(C) ]
"Fuel grade ethanol", means ethanol that has been blended with at least 2% gasoline per the US Tax and Trade Bureau to render the product unsuitable for human consumption. This product must meet the American Society for Testing and Materials standard in effect January 1, 1995, and successor rules, as the D-4806 specification for denatured fuel grad ethanol for further blending with gasoline for use as automatic spark-ignition engine fuels.
Okla. Admin. Code § 710:55-1-2