What are the numbers engraved on plastic containers?

What are the numbers engraved on plastic containers?

What are the numbers engraved on plastic containers?

The US Society of the Plastics Industry introduced the Resin Identification Code (RIC) system in 1988, when the organization was called Society of the Plastics Industry, Inc. (SPI). The SPI stated that one purpose of the original SPI code was to "Provide a consistent national system to facilitate recycling of post-consumer plastics."[2] The system has been adopted by a growing number of communities implementing recycling programs, as a tool to assist in sorting plastics. In order to deal with the concerns of recyclers across the U.S., the RIC system was designed to make it easier for workers in materials recovery and recycling facilities to sort and separate items according to their resin type.[citation needed] Plastics must be recycled separately, with other like materials, in order to preserve the value of the recycled material, and enable its reuse in other products after being recycled.

In its original form, the symbols used as part of the RIC consisted of arrows that cycle clockwise to form a triangle that encloses a number. The number broadly refers to the type of plastic used in the product, by chronological order[citation needed] of when that plastic became recyclable:

    "1" signifies that the product is made out of polyethylene terephthalate (PET) (beverage bottles, cups, other packaging, etc.)
    "2" signifies high-density polyethylene (HDPE) (bottles, cups, milk jugs, etc.)
    "3" signifies polyvinyl chloride (PVC) (pipes, siding, flooring, etc.)
    "4" signifies low-density polyethylene (LDPE) (plastic bags, six-pack rings, tubing, etc.)
    "5" signifies polypropylene (PP) (auto parts, industrial fibres, food containers, etc.)
    "6" signifies polystyrene (PS) (plastic utensils, Styrofoam, cafeteria trays, etc.)
    "7" signifies other plastics, such as acrylic, nylon, polycarbonate and polylactic acid (PLA).

When a number is omitted, the arrows arranged in a triangle form the universal recycling symbol, a generic indicator of recyclability. Subsequent revisions to the RIC have replaced the arrows with a solid triangle, in order to address consumer confusion about the meaning of the RIC, and the fact that the presence of a RIC symbol on an item does not necessarily indicate that it is recyclable.

In 2008, ASTM International took over the administration of the RIC system and eventually issued ASTM D7611—Standard Practice for Coding Plastic Manufactured Articles for Resin Identification.[3] In 2013 this standard was revised to change the graphic marking symbol of the RIC from the "chasing arrows" of the Recycling Symbol to a solid triangle instead.

Since its introduction, the RIC has often been used as a signifier of recyclability, but the presence of a code on a plastic product does not necessarily indicate that it is recyclable any more than its absence means the plastic object is [necessarily] unrecyclable.