
In hope of satiating their environmentally-conscious guilt, many consumers look for markings on plastic products to determine if their items can be discarded in the recycling bin. However, this isn’t the intent of these markings. They’re Resin Identification Codes (RICs), and, as noted in ASTM D7611/D7611M-20: Standard Practice For Coding Plastic Manufactured Articles For Resin Identification:
“Resin Identification Codes are not ‘recycle codes.’ The Resin Identification Code is, though, an aid to recycling. 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.”
Resin Identification Codes are used solely to identify the plastic resin used in a manufactured article. Back in 1988, this coding system was first developed by the Society of the Plastics Industry, Inc. (SPI), but it has since been administered by ASTM International.
According to the current ASTM standard that specifies RICs, ASTM D7611/D7611M-20, a Resin Identification Code consists of an equilateral triangle, a Resin Identification Number, and an Abbreviated Term for polymeric material. For example:

Numbered 1-7, the different type of plastic resins addressed include (1) poly (ethylene terephthalate), (2) high density polyethylene, (3) poly (vinyl chloride), (4) low density polyethylene, (5) polypropylene, (6) polystyrene, and (7) other resins.
As you can note in the above example, which is Figure 1 in the ASTM D7611/D7611M-20 standard, current Resin Identification Codes are surrounded by an equilateral triangle, which has a bold outline. Many may be used to seeing these codes with a triangle that closely resembles the Universal Recycling Symbol. However, this is no longer the appearance of Resin Identification Codes, due to a change incorporated into a previous edition of ASTM D7611 that was enacted to limit any misplaced associations of RICs with recycling codes.