In the American Society for Testing Materials plastics committee’s work to revise the resin identification code (RIC) standard — ASTM D7611 — it has changed the graphic marking symbol used to identify resin type from the “chasing arrows” symbol surrounding a numeral from 1 to 7 that defines the resin used in the product’s packaging to a solid equilateral triangle around the number.
The RIC system was originally developed and continues to be dedicated to identifying resin content, rather than product recyclability. ASTM says that by replacing the chasing arrows graphic — commonly associated with recycling — with an equilateral triangle, ASTM D7611 helps bring focus back to the system’s core mission: resin identification and quality control prior to recycling.
ASTM says the revisions are intended to modernize the RIC system, making them easier to use while also addressing recent innovations in polymer applications and multi-layer materials.
The Society of the Plastics Industry (SPI) developed the RIC in 1988 to meet the needs of recyclers and manufacturers for a consistent, uniform coding system that can be applied worldwide. SPI began work with ASTM in 2008 to involve technical and industry stakeholders in updating and maintaining the RIC system to better address advancements in plastics materials.
Originally intended to assist waste recovery facilities in the quality sorting of plastics products prior to recycling, the RIC system has today become a vital foundational tool used by municipalities, scrap brokers, recyclers, manufacturers, consumers and others for managing the end-of-life of plastics materials.
Bridget Anderson, director, Recycling Unit, Bureau of Waste Prevention, Reuse and Recycling, NYC Department of Sanitation, participated in the development of the revised D7611 standard as a member of the task group. She says changing the marking symbol in D7611 decouples the RIC system from the recycling message, which has caused public confusion.
ASTM D7611 provides codes for the six most commonly found resin types, with a seventh category created for all other types. These categories include: 1) polyethylene terephthalate (PETE); 2) high density polyethylene (HDPE); polyvinyl chloride (V); 4);low density polyethylene (LDPE); 5) polypropylene (PP); 6) polystyrene (PS); and 7) other, including materials made with more than one resin from categories 1-6.
As part of its ongoing efforts, the task group is assessing how to: differentiate between different melt flows within each resin; identify certain additives that might significantly change the properties of a resin; and better label individual resins (PLA, PC, ABS, Nylon, and others) that are currently designated as “other” in the current RIC system. The task group is also discussing whether a new code is needed for linear low density polyethylene (LLDPE) to enable products made from this technology to be accurately identified and distinguished from products marked as HDPE or LDPE.