(1) An exemption from the taxes imposed in this chapter is provided for:
(a) Producers, with respect to environmental handling charges added to the purchase price of mercury-containing lights either by the producer or a retailer pursuant to an agreement with the producer;
(b) Retailers, with respect to environmental handling charges added to the purchase price of mercury-containing lights sold at retail, including the portion of environmental handling charges retained as reimbursement for any costs associated with the collection and remittance of the charges; and
(c) Stewardship organizations, with respect to environmental handling charges received from producers and retailers and to the receipts from charges to participating producers and legacy producers.
(3) For purposes of this section, the definitions in RCW
70A.505.020 apply.