RCW 70A.220.020: Plastic bottle or rigid plastic container—Labeling requirements.

Except as provided in RCW 70A.220.030(2), after January 1, 1992, no person may distribute, sell, or offer for sale in this state a plastic bottle or rigid plastic container unless the container is labeled with a code identifying the appropriate resin type used to produce the structure of the container. The numbers and letters used shall be as follows:

(a) [(1)] 1.= PETE (polyethylene terephthalate)

(b) [(2)] 2.= HDPE (high-density polyethylene)

(c) [(3)] 3.= V (vinyl) or PVC (polyvinyl chloride)

(d) [(4)] 4.= LDPE (low density polyethylene)

(e) [(5)] 5.= PP (polypropylene)

(f) [(6)] 6.= PS (polystyrene)

(g) [(7)] 7.= OTHER