All packages and packaging components shall be subject to this chapter except the following:

(1) Those packages or package components with a code indicating date of manufacture that were manufactured prior to May 21, 1991;

(2) Those packages or packaging components that have been purchased by, delivered to, or are possessed by a retailer on or before twenty-four months following May 21, 1991, to permit opportunity to clear existing inventory of the proscribed packaging material;

(3) Those packages or packaging components to which lead, cadmium, mercury, or hexavalent chromium have been added in the manufacturing, forming, printing, or distribution process in order to comply with health or safety requirements of federal law or for which there is no feasible alternative; or

(4) Those packages and packaging components that would not exceed the maximum contaminant levels set forth in RCW 70A.222.020(1) but for the addition of postconsumer materials; and provided that the exemption for this subsection shall expire six years after May 21, 1991.