RCW 82.08.865: Exemptions—Diesel, biodiesel, and aircraft fuel for farm fuel users.

(1) The tax levied by RCW 82.08.020 does not apply to sales of diesel fuel, biodiesel fuel, or aircraft fuel, to a farm fuel user for agricultural purposes. This exemption applies to a fuel blend if all of the component fuels of the blend would otherwise be exempt under this subsection if the component fuels were sold as separate products. This exemption is available only if the buyer provides the seller with an exemption certificate in a form and manner prescribed by the department. (2) The definitions in RCW 82.04.213 and this subsection apply to this section. (a)(i) "Agricultural purposes" means the performance of activities directly related to the growing, raising, or producing of agricultural products. (ii) "Agricultural purposes" does not include: (A) Heating space for human habitation or water for human consumption; or (B) transporting on public roads individuals, agricultural products, farm machinery or equipment, or other tangible personal property, except when the transportation is incidental to transportation on private property and the fuel used for such transportation is not subject to tax under chapter 82.38 RCW. (b) "Aircraft fuel" is defined as provided in RCW 82.42.010 . (c) "Biodiesel fuel" is defined as provided in RCW 19.112.010 . (d) "Diesel fuel" is defined as provided in 26 U.S.C. 4083, as amended or renumbered as of January 1, 2006. (e) "Farm fuel user" means: (i) A farmer; or (ii) a person who provides horticultural services for farmers, such as soil preparation services, crop cultivation services, and crop harvesting services.