The series of recycling symbols on plastic items—a triangle with a number from 1 to 7 inside—can often tell you which kind of plastic the item is made of and how recyclable it is. The symbols—then collectively called the Resin Identification Code (RIC)—were developed in 1988 by the organization now known as the Plastics Industry Association. The symbols are currently administered by ASTM International, an organization that designs and sets standards for a wide range of industries, and go by the official name ASTM International Resin Identification Coding System.
The symbols first included three bent arrows in the shape of a triangle. The solid triangles were introduced in 2013.
ASTM is working on further modifications to the system, which has been criticized for not making it clear whether a certain type of plastic is actually recyclable; the presence of a recycling symbol is not in and of itself an indicator that a particular plastic will be accepted at your local recycling center or by your recyclables and waste collector.
In the U.S., How2Recycle labels that describe whether and how various items, including plastics, may be recycled are gaining in use. These labels can tell you what you should do to prepare the item for recycling (if applicable); whether it is widely recycled, recycled in only limited places, not recycled, or recycled by dropping off at a specific location, such as a grocery store; the type of recyclable material; and the component or components that are recycled.
In the meantime, the RIC system is still in place and helpful for both consumers and those who want to run a plastics recycling operation, which generally deals with packaging used for consumer products. Each number represents a type of plastic, and different types of plastics are generally used in the same types of packaging.
Polyethylene Terephthalate (PETE or PET)
A 1 inside the triangle indicates the plastic is polyethylene terephthalate, which is shortened to PET or PETE. This symbol is normally found on bottles for soft drinks and water; salad dressing, peanut butter, and vegetable oil containers; and mouthwash bottles.
PET bottles can be recycled into new containers, pallet straps, paneling, carpet and clothing fibers, and fiberfill for soft furnishings and sleeping bags.
Although there is demand for recycled PET, the recycling rate in the U.S. was 29.2% in 2017, the latest year for which data was available, according to the National Association for PET Container Resources (NAPCOR) and the Association of Plastic Recyclers (APR).
High-Density Polyethylene (HDPE)
A 2 inside the triangle indicates the plastic is high-density polyethylene, or HDPE. You can find HDPE in milk jugs, shampoo bottles, butter and yogurt tubs, motor oil bottles, shopping and trash bags, bags inside cereal boxes, and household cleaner and detergent bottles.
This plastic can be recycled into lumber, drainage pipes, pens, fencing, picnic tables, doghouses, benches, and floor tiles, in addition to bottles and other containers.
The recycling rate for HDPE bottles was 31.1% in 2017.
Vinyl (V or PVC)
A 3 inside the triangle indicates the plastic is vinyl or polyvinyl chloride. You can find vinyl in piping, siding, medical equipment, wire jacketing, certain clear food packaging, and cooking oil, window cleaner, detergent, and shampoo bottles.
Vinyl is rarely recycled. A tiny percentage of PVC is recycled into mats, speed bumps, cables, flooring, roadway gutters, mud flaps, paneling, and decks.
Low-Density Polyethylene (LDPE)
A 4 inside the triangle indicates the plastic is low-density polyethylene, or LDPE. This plastic is commonly found in shopping bags, squeezable bottles, carpet, furniture, clothing, tote bags, dry cleaning bags, and frozen food or bread bags.
LDPE is rarely recycled. When it is, it can be made into floor tile, lumber, paneling, shipping envelopes, compost bins, trash cans, and bubble wrap.
A 5 inside the triangle indicates the plastic is polypropylene or PP. It is commonly found in medicine bottles, straws, bottle caps, ketchup bottles and syrup bottles, and some yogurt containers. This plastic is often chosen for bottles and containers that must accept hot liquids as it has a high melting point.
PP is rarely recycled. When it is, it can be made into trays, pallets, bins, rakes, bicycle racks, landscape borders, ice scrapers, auto battery cases, brushes, brooms, battery cables, and signal lights.
A 6 inside the triangle indicates the plastic is polystyrene (PS), which is also erroneously referred to as Styrofoam, the name of a Dow-trademarked brand of polystyrene insulation. You can find PS in disposable cups and plates, carry-out containers, egg cartons, and meat trays.
It is generally considered to be difficult to recycle and has been banned in some municipalities in the U.S. It is possible to recycle PS into packaging and containers, as well as foam packing, light switch plates, and insulation.
Any plastic that does not fall under one of those six types has a 7 inside the triangle. These plastics include nylon and polycarbonate and are found in certain food containers, signs and displays, computers and electronic devices, DVDs, sunglasses, and bulletproof materials.
These plastics are almost never recycled, but they could be transformed into plastic lumber and certain custom-made products.