Resin Identification Codes
The Resin Identification Code was an industry invention that was carried through many state legislatures in the late 1980s during a time of increased attention on the proliferation of plastics and and an increased awareness over the need for recycling. Although the resin code is valuable in that it identifies for consumers and recyclers the types of resin being used, it is often misinterpreted to denote that all plastics with a resin code are actually recycled. In reality, generally only plastics #1 (PETE) and #2 (HDPE) are economical to recycle and thus are accepted widely in curbside programs and dropoff centers.
Some beverage containers, such as milk jugs, which are widely recyclable and accepted in curbside programs. Other uses, such as for shopping bags, are recycled less and are not accepted in curbside programs.
Foamed form used in takeout food packaging and is not accepted in curbside programs as it is uneconomical to recycle. Its solid form, used to make hard casings such as CD jewel cases, is not accepted in curbside programs either. PS is a principle component of marine debris and litter.
Other plastics, including composites, which are not accepted in curbside programs. Currently the other category includes compostable bioplastics such as PLA, which are accepted in some curbside food composting programs.