(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.
(3) For purposes of this section, the definitions in RCW
70A.505.020 apply.