Resin identification code

Main article: Recycling codes

Sorted household plastic waiting to be hauled away for reprocessing.

Polypropylene lid of a Tic Tac 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 is used internationally. The primary purpose of the codes is to allow efficient separation of different polymer types for recycling. Separation must be efficient because the plastics must be recycled separately. Even one item of the wrong type of resin can ruin a mix.

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 arbitrarily assigned number that 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 in the Miscellaneous Symbols block. The generic material recycling symbol is encoded as code point U+267A.

Table of resin codes

Recycling number	Image	Unicode	Alternate images	Symbol	Abbreviation	Polymer name	Uses
1		U+2673		♳	PETE or PET	Polyethylene terephthalate	Polyester fibers, thermoformed sheet, strapping, and soft drink bottles (See also: Recycling of PET bottles)
2		U+2674		♴	HDPE	High-density polyethylene	Bottles, grocery bags, milk jugs, recycling bins, agricultural pipe, base cups, car stops, playground equipment, and plastic lumber
3		U+2675		♵	PVC or V	Polyvinyl chloride	Pipe, fencing, shower curtains, lawn chairs, non-food bottles and children's toys.
4		U+2676		♶	LDPE	Low-density polyethylene	Plastic bags, 6 pack rings, various containers, dispensing bottles, wash bottles, tubing, and various molded laboratory equipment
5		U+2677		♷	PP	Polypropylene	Auto parts, industrial fibers, food containers, and dishware
6		U+2678		♸	PS	Polystyrene	Desk accessories, cafeteria trays, plastic utensils, toys, video cassettes and cases, clamshell containers, packaging peanuts, and insulation board and other expanded polystyrene products (e.g., Styrofoam)
7		U+2679		♹	OTHER or O	Other plastics, such as acrylic, nylon, polycarbonate, and polylactic acid (a bioplastic), and multilayer combinations of different plastics	Bottles, plastic lumber applications, Headlight lenses, and safety shields/glasses.
9 or ABS					ABS	Acrylonitrile butadiene styrene	High-impact and chemical-resistant extruded or molded objects

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 many communities throughout the United States, PETE and HDPE are the only plastics collected in municipal recycling programs (e.g. Mackinaw City, Michigan). 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.)

Possible new codes

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

See also

• Linear low-density polyethylene
• List of symbols

External links

• Recycling Symbols for Plastics has symbols used in plastics recycling available in various formats for use in graphics and packaging.
• Your Recycling Quandaries Information from Co-op America about what really happens when plastic is "recycled".
• Resin Codes from the American Chemistry Council.