(1) The tax levied by RCW 82.08.020 does not apply to sales of waste vegetable oil that is used by a person in the production of biodiesel for personal use.
(2) This exemption is available only if the buyer provides the seller with an exemption certificate in a form and manner prescribed by the department.
(3) For the purposes of this section, the following definitions apply:
(a) "Waste vegetable oil" means used cooking oil gathered from restaurants or commercial food processors; and
(b) "Personal use" means the person does not engage in the business of selling biodiesel at wholesale or retail.