plastics recycling code

In 1988 the Plastic Bottle Institute, a division of the Society of the Plastic Industry, developed a code to be molded into plastic bottles so that the resin from which the object was made could be easily identified during recycling. A bale consisting entirely of bottles made from the same resin can be put to many more uses than a bale of mixed resins, and is much more valuable. Thirty-nine states incorporated the code into their waste management legislation.

The best general source of information on the web on where to recycle plastic is:


Click “Where to recycle” at the top of the page, then “plastic” in the list on the left. Select the resin number and form (such as "sheet") from the list that appears, and finally, enter your zip code (preferably) or city or state in the form.

Here, below, are links to websites offering recyling or simply advice for particular resins. We have found many of these sites come and go pretty quickly. Please write us if you find better sources.

symbol for polyethylene terphthalate, number 1

Polyethylene terphthalate.

By far the most valuable of the recycled plastics, and the one most often recycled. It is made into stuffing for pillows, sleeping bags, and quilts, into the fuzz on tennis balls and the tennis ball “can,” carpet, twine combs, car bumpers, and many other products.

PET Resin Assn.

symbol for high density polyethylene, number 2

High-density polyethylene.

symbol for vinyl and polyvinyl chloride, number 3

Vinyl or polyvinyl chloride.

About half of the PVC made in North America is used for pipes. Worldwide, piping is the largest single use. Siding for houses, flooring, packaging, shower curtains, insulation for electrical wiring, packaging films to credit cards, often in combination with other resins.

Almost all contain additives, plasticizers and stabilizers specific to the intended use.

Vinyl Institute

symbol for low density polyethylene, number 4

Low-density polyethylene.

Found in plastic bags, tubing

symbol for polypropylene, number 5


Often found in the more durable sorts of packaging.

symbol for polystyrene, number 6


Clear glasses. Often in the form of expanded polystyrene (EPS), often called by the name of Dow's product, Styrofoam. EPS is an excellent thermal insulator, and is used take-out food packaging, coffee cups and clamshells, coolers.

Recycling of EPS from pre-consumer sources is common. EPS from consumers presents difficulties.

EPS Industry Alliance site index
EPS Industry Alliance recycling

symbol for other resins, number 7

None of the above. Sometimes the plastic resin is one of those listed above, but it contains an additive which makes it unsuitable for recycling.

polycarbonate (football helmets and eyeglasses), acrylic ("Plexiglas"),

Symbols by Bhutajata (CC0)

That the symbols met a great need was proven by their rapid spread worldwide, sometimes with minor modifications. In China and the UK, for example, the numbers are two-digit, that is, “07” instead of “7”.That style is common globally.

RIC: Resin identification without reference to recycling

The recycling symbols are often misinterpreted as meaning that, if a marked item is placed in a recycling bin, it will be recycled. That is not necessarily true. Whether the item will be recycled depends on a number of factors, including the current price of the recovered resin, and, above all, location. For example, in greater Los Angeles, a resin may be recycled in one city, but not in a separate but contiguous city one block away. Another important factor is the physical form of the object. It is much easier to recycle polyethylene jugs than polyethylene sheets.

Although bottle manufacturers invented the original code to faciliate recycling, its wide acceptance made obvious the usefulness of marking objects to show what resin they're made of. Unfortunately, the arrows imply that the marked object can be recycled, which is usually not the case. Another shortcoming of the SPI system was that it focused on resins used in bottles. The usefulness of the marking could be greatly increased by adding numbers for other resins.

In 2008, The ASTM accepted responsibility¹ for fixing these problems.

In 2010, ASTM issued a standard D7611 that assigned additional numbers to other resins.

In 2013, the standard was revised to get rid of the arrows, because they imply a marked item will be recycled. ASTM replaced them with a simple equilateral triangle, thus equilateral triangle icon

1. An ASTM press release.


ASTM D7611 / D7611M-20, Standard Practice for Coding Plastic Manufactured Articles for Resin Identification, ASTM International, West Conshohocken, PA, 2020,

ASTM WK69220 Revision of D7611 / D7611M - 19 Standard Practice for Coding Plastic Manufactured Articles for Resin Identification .