What Do the Numbers on Plastic Packaging Mean?

The numbers inside the recycling triangle (Resin Identification Codes) identify the type of plastic resin used in the product. They were developed by the Society of the Plastics Industry.

1 — PET (Polyethylene terephthalate): Water bottles, food containers. Widely recycled. 2 — HDPE (High-density polyethylene): Milk jugs, detergent bottles. Widely recycled. 3 — PVC (Polyvinyl chloride): Pipes, flooring. Rarely recycled. 4 — LDPE (Low-density polyethylene): Plastic bags, squeeze bottles. Sometimes recycled. 5 — PP (Polypropylene): Yogurt containers, bottle caps. Increasingly recycled. 6 — PS (Polystyrene): Foam cups, packaging. Rarely recycled. 7 — Other: Mixed or other plastics. Rarely recycled.