The resin identification code (RIC) is a standardized system of symbols developed in 1988 by the Society of the Plastics Industry (now the Plastics Industry Association) and is widely used on plastic products to identify the type of plastic in attempt to facilitate its sorting for recycling.
The code appears as a number from 1 to 7 inside a triangle. Each number represents a specific category of plastics: 1 for PET (polyethylene terephthalate), 2 for HDPE (high-density polyethylene), 3 for PVC (polyvinyl chloride), 4 for LDPE (low-density polyethylene), 5 for PP (polypropylene), 6 for PS (polystyrene) and 7 for plastics not covered by the other codes and less commonly recycled (such as acrylic, nylon, polycarbonate and bioplastics).
Unfortunately, this system is far from perfect. A major problem is that the symbols are frequently mistaken for the universal recycling symbol, leading consumers to believe that all plastics marked with them are recyclable. This is often not the case, thus resulting in contamination of plastics being recycled and improper disposal. The resin identification codes were designed to identify resin types for sorting and quality control, not to indicate whether a particular item can be recycled in a particular community or contains recyclable material.
Some plastic products bearing the codes require specialized recycling facilities that are not widely available. Also, each of the seven codes covers a range of plastic materials with varying properties and different recycling requirements, thus complicating sorting and reducing recycling effectiveness.
Despite the initial promise of RICs and their subsequent widespread implementation, overall plastic waste recycling rates remain low, with less than ten percent being recycled worldwide. The vast majority is continuing to accumulate in landfills, be incinerated, get dumped into water bodies, etc. This is an indication that additional, much stronger measures need to be implemented, focussing mainly on reducing the production and use of petroleum-derived plastics and developing fully biodegradable alternatives.
Nevertheless, it would still be useful to further improve the RIC system. This could include adding more codes to allow for finer grained sorting of plastic types lumped into the existing seven broad categories and to add newly emerging types such as 3D printed plastics. It should also include expanding consumer education.