Resin identification code

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Sorted household plastic waiting to be hauled away for reprocessing.
Polypropylene lid of a Tic Tacs box, with a living hinge and the resin identification code under its flap

The SPI resin identification coding system is a set of symbols placed on plastics to identify the polymer type. It was developed by the Society of the Plastics Industry (SPI) in 1988, and used internationally.

Most plastics can be recycled, but they have to be separated into their different polymer types. Because of the difficulty and expense of sorting, collecting, cleaning and reprocessing, at the moment it is only economically viable to recycle PETE and HDPE.[citation needed] Thermoplastics can be remelted, but thermosetting plastics can only be crushed and used as insulation.[citation needed]

The symbols used in the code consist of arrows that cycle clockwise to form a rounded triangle and enclosing a number, often with an acronym representing the plastic below the triangle. When the number is omitted, the symbol is known as the universal Recycling Symbol, indicating generic recyclable materials. In this case, other text and labels are used to indicate the material(s) used. Previously recycled resins are coded with an "R" prefix (for example, a PETE bottle made of recycled resin could be marked as RPETE using same numbering).

Contrary to misconceptions, the number does not indicate how hard the item is to recycle, nor how often the plastic was recycled. It is an arbitrary number and has no other meaning aside from identifying the specific plastic.

The Unicode character encoding standard includes the resin identification codes, between code points U+2673 and U+2679 inclusive. The generic material recycling symbol is encoded as code point U+267A.

Contents

[edit] Table of resin codes

Recycling number Image Unicode Symbol Abbreviation Polymer name Uses once recycled
1 ♳ #x2673; PETE or PET Polyethylene terephthalate Polyester fibres, thermoformed sheet, strapping, and soft drink bottles

(See also: Recycling of PET Bottles)

2 ♴ #x2674; HDPE High density polyethylene Bottles, grocery bags, recycling bins, agricultural pipe, base cups, car stops, playground equipment, and plastic lumber
3 ♵ #x2675; PVC or V Polyvinyl chloride Pipe, fencing, and non-food bottles
4 ♶ #x2676; LDPE Low density polyethylene Plastic bags, 6 pack rings, various containers, dispensing bottles, wash bottles, tubing, and various molded laboratory equipment
5 ♷ #x2677; PP Polypropylene Auto parts, industrial fibers, food containers, and dishware
6 ♸ #x2678; PS Polystyrene Desk accessories, cafeteria trays, plastic utensils, toys, video cassettes and cases, and insulation board and other expanded polystyrene products (e.g., Styrofoam)
7 ♹ #x2679; OTHER or O Other plastics, including acrylic, acrylonitrile butadiene styrene, fiberglass, nylon, polycarbonate, and polylactic acid  

[edit] Availability of recycling facilities

Use of the recycling symbol in the coding of plastics has led to ongoing consumer confusion about which plastics are readily recyclable. In most communities throughout the United States, PETE and HDPE are the only plastics collected in municipal recycling programs. Some regions, though, are expanding the range of plastics collected as markets become available. (Los Angeles, for example, recycles all clean plastics numbered 1 through 7.[1])

[edit] Possible new codes

In 2007, a State Senate bill in California (SB 898) proposed adding a "0" code for compostable polylactic acid.[2] However, this provision of the bill was removed before passage.[3][4]

[edit] See also

[edit] References

  1. ^ http://www.lacity.org/san/solid_resources/recycling/what_is_recyclable.htm "What is Recyclable" from the City of Los Angeles Bureau of Sanitation website.
  2. ^ http://www.leginfo.ca.gov/cgi-bin/postquery?bill_number=sb_898&sess=CUR&house=B&author=simitian Full text and version history of California State Senate Bill 898
  3. ^ http://www.cawrecycles.org/issues/current_legislation/sb898_07 Bill summary from Californians Against Waste, an environmental group
  4. ^ SB 898 Senate Bill - AMENDED

[edit] External links

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