However, there are certain variables that complicate recycling, since not all plastics are universally recyclable. Compare polyethylene terephthalate (PET) and polyvinyl chloride (PVC): the former is one of the most commonly used plastics in consumer bottles, while the latter is found in the sheathing material for computer cables, plastic pipes, and some consumer products. Both of these materials are visibly plastic, but PET is always recyclable and PVC can almost never be recycled.
Because of this distinction, there has long been a need for manufacturers of plastic products to convey their products’ recyclability and material components to consumers and recyclers, so that the plastics can be disposed of properly. Assuring responsible end use of fabricated products is an important manufacturer responsibility, and a standard system of identifiable markings helps to fulfill this duty.
The standard system of symbols that appears on plastic products to mark the predominant plastic material present is that of the Resin Identification Code (RIC Code). This coding system was first developed by the Society of the Plastics Industry, Inc. (SPI) back in 1988, but it has since been administered by ASTM International.
The current standard for RIC Code is specified in ASTM D7611/D7611M-13E1 - Standard Practice for Coding Plastic Manufactured Articles for Resin Identification, which defines it as “a molded, imprinted or raised symbol or wording that consists of an equilateral triangle, a Resin Identification Number, and an Abbreviated Term for polymeric material.”
Since a Resin Identification Code exists for the owner of a plastic product to be able to understand its main plastic material, the most important part of the Code is the resin. RIC Codes are used to identify seven different types of plastic resins, which are numbered 1-7. These are (1) polyethylene terephthalate, (2) high-density polyethylene, (3) polyvinyl chloride, (4) low-density polyethylene, (5) polypropylene, (6) polystyrene, and (7) other plastics.
These numbers are placed inside the equilateral triangle, with the abbreviated term for the material just under it. For example, the code for high-density polyethylene is:
While many have believed a Resin Identification Number to be the code indicating plastic recyclability, it actually is meant to assist recyclers in sorting the collected materials, and it can even better inform consumers. This is noted in the ASTM D7611/D7611M-13E1 standard:
“Resin Identification Codes are not ‘recycle codes.’ The use of a Resin Identification Code on a manufactured plastic article does not imply that the article is recycled or that there are systems in place to effectively process the article for reclamation or re-use. The term “recyclable” or other environmental claims shall not be placed in proximity to the Code.”
This misunderstanding can explain one of the primary changes to the latest revision of ASTM D7611/D7611M-13E1: the change from a triangle closely resembling the Universal Recycling Symbol to one with a bold outline. And, while Resin Identification Codes are not recycle codes, they can help consumers identify the plastic present so that they can dispose of it according to local recycling laws, which vary from place to place.
For example, in the United States, there are no federal regulations for recycling, so laws pertaining to recycling are determined by state and local government. Through this, there is a lot of variation in recycling guidelines. In fact, the only true recycling standard is the Universal Recycling Symbol itself, the easily identifiable image containing three identical chasing arrows.
The Universal Recycling Symbol traces its origins back to the first Earth Day, when environmental consciousness was in early emergence. Around the first Earth Day in 1970, the Container Corporation of America (CCA) held a competition to create a design representative of recycling. The winner of this contest was Gary Dean Anderson, a then-23 year old college student who drew inspiration from the Mobius Strip to create the Universal Recycling Symbol.
In the decades since this time, the Universal Recycling Symbol has vastly grown in use, being internationally recognized and actually becoming the universal symbol for recycling.
Ultimately, it is important remain aware of local laws on recycling and be able to identify plastic components used in products. If a plastic material can be recycled according to local laws, then it absolutely should be, as it can then be reused for another product instead of resting in a landfill for the next half millennium.
1. ASTM International, ASTM D7611/D7611M-13E1 - Standard Practice for Coding Plastic Manufactured Articles for Resin Identification (West Conshohocken: ASTM, 2014), 3.