Plastic Recycling Codes 1-7: What Each Number Means

Introduction — Why the Triangle With a Number Is Everywhere

Flip over almost any plastic object in your kitchen — a yogurt tub, a ketchup bottle, a shampoo pump — and you will find it. A small triangle of three chasing arrows with a number inside. Most people glance at it, assume it means “this is recyclable,” and toss the item in the blue bin. That assumption is wrong more often than not.

The triangle is a resin identification code (RIC), and despite its recycling-friendly appearance, it was never designed to tell consumers whether something can actually be recycled. It was designed to tell sorting facilities what kind of plastic they are looking at. The distinction matters: a code #1 PET bottle is one of the most successfully recycled objects on the planet, while a code #3 PVC fragment in the same bin can contaminate an entire bale.

This pillar article is a reference-grade walkthrough of all seven plastic recycling codes. For each number, you will find the full chemical name, common uses, physical properties, a recyclability score, and what the material typically becomes when recycled — usually something of lower value, a process known as downcycling. By the end, you should be able to pick up any plastic item, read its code, and know exactly what you are holding.

The History of Resin Identification Codes

The resin identification code system was introduced in 1988 by the Society of the Plastics Industry (SPI), the trade association now known as the Plastics Industry Association (PLASTICS). The goal was industrial: recyclers were struggling to sort post-consumer streams, and molders needed a standard way to label resin type on a finished product.

SPI chose a triangle of three chasing arrows — the “Mobius loop” Gary Anderson designed in 1970 — and placed a single digit inside it. The seven numbers corresponded to the six most common commodity resins plus a catch-all “other” category. From the start, SPI insisted the symbol was a resin ID, not a recyclability claim. That nuance was lost almost immediately. Consumers saw the arrows and assumed the triangle meant the bin.

In 2013, ASTM International took over stewardship and published ASTM D7611, formally renamed the “Standard Practice for Coding Plastic Manufactured Articles for Resin Identification.” Critically, ASTM D7611 replaced the chasing-arrows triangle with a solid equilateral triangle — three straight lines — to reduce visual confusion with recycling claims. The numbering stayed the same. Most countries now use ASTM D7611, the ISO 1043 polymer shorthand, or the European Commission’s 97/129/EC marking scheme. In practice, molds are expensive to change, so older chasing-arrows triangles are still produced by the billions every year. Both forms mean the same thing.

How to Read a Recycling Code

Finding the code is usually straightforward. On bottles and rigid containers, look at the bottom center — the code is embossed into the plastic itself, not printed on the label, so it survives washing. On flexible packaging like bags and films, it is often printed on a flat seam. On large items (crates, buckets, automotive parts), it may be stamped on the inside wall or near a mold gate mark.

What you are looking at is a small triangle, typically 8-12 millimeters across, containing a single digit from 1 to 7. Beneath the triangle you will usually find a two-to-four-letter abbreviation: PET or PETE, HDPE, PVC or V, LDPE, PP, PS, or OTHER. That abbreviation is the polymer’s shorthand name and is the most reliable part of the marking — if the digit has worn away but the letters remain, you still have your answer.

A few things the code does not tell you. It does not tell you whether your local municipality accepts that resin in curbside pickup — that depends on the contracts your material recovery facility has with buyers. It does not tell you whether the plastic contains additives, colorants, flame retardants, or fillers that may disqualify it from high-value streams. And it does not tell you whether the object is a single resin or a multi-layer laminate. A juice pouch with a code #7 might be PET bonded to aluminum bonded to LDPE — technically “other,” practically unrecyclable. Read the code as a starting point, not a verdict.

Code #1 — PET / PETE (Polyethylene Terephthalate)

Polyethylene terephthalate, abbreviated PET or PETE, is the workhorse of the beverage industry and the single most recycled plastic in the world. It is a clear, glossy, slightly bluish polyester that is tough, shatter-resistant, and an excellent barrier to oxygen and carbon dioxide — which is why it dominates carbonated drinks, bottled water, and edible oils. PET is also hard to tear with bare hands, and when you squeeze an empty bottle it makes a distinctive crinkling sound.

Common uses:

• Single-use water and soft drink bottles
• Edible oil, salad dressing, and vinegar bottles
• Clear peanut butter jars
• Clear clamshell packaging for berries and salads
• Polyester fiber for fleece, carpets, and t-shirts (rPET)
• Cosmetic containers
• Microwaveable CPET food trays

Virgin PET is transparent and almost colorless, with a rigid but slightly flexible wall. It feels cool and smooth and softens around 80 °C, which is why you should never pour boiling water into a PET bottle. Pigmented PET appears in green soda bottles and amber medicine bottles, but uncolored grade is most valuable to recyclers because it can be dyed any color downstream.

Recyclability score: high. PET has mature, high-volume recycling infrastructure in North America, Europe, Japan, and a growing number of emerging markets. Clean sorted PET bales trade on commodity markets and PET is the only plastic for which bottle-to-bottle closed-loop recycling is commercially routine. Countries with deposit-return schemes (Germany, Norway, Lithuania) achieve collection rates above 90 percent.

Typical downcycled products: polyester fiber for clothing and carpets, strapping for shipping pallets, thermoformed trays, and pillow fillings. When the closed loop is maintained, recycled PET (rPET) can become new food-contact bottles — the EU now mandates 25 percent rPET content in PET beverage bottles by 2025, rising to 30 percent by 2030. For a deeper dive see our PET resin properties page. PET is recycled primarily through mechanical recycling, which slightly degrades the polymer each cycle; chemical depolymerization can return it to virgin-grade monomers but remains expensive.

Code #2 — HDPE (High-Density Polyethylene)

High-density polyethylene, HDPE, is the quiet giant of the plastics world — opaque, stiff, chemically inert, and almost indestructible in everyday use. If PET is the material of clear bottles, HDPE is the material of opaque ones: the milky gallon of milk, the bright red bottle of laundry detergent, the thick white jug of motor oil. HDPE has the simplest molecular structure of any commodity plastic and is one of the cheapest resins to produce per kilogram.

Common uses:

• Milk, juice, and water gallon jugs
• Shampoo, conditioner, and body-wash bottles
• Laundry detergent and household cleaner bottles
• Motor oil and antifreeze containers
• Pipe and conduit for water and gas distribution
• Plastic lumber and playground equipment
• Food tubs (butter, ice cream, deli)

HDPE feels waxy and slightly slippery, with a matte or semi-gloss finish. It is stiffer than LDPE but still flexes without cracking. You can identify it by the dull “thud” it makes when dropped — where PET rings, HDPE thuds. Most HDPE is naturally translucent white; pigments produce the bright colors seen on detergent bottles.

Recyclability score: high. HDPE is the second-most-recycled plastic after PET and is widely accepted in curbside programs across North America and Europe. Recyclers separate HDPE into two streams: natural (uncolored, highest value) and pigmented (lower value). Both have robust end markets. See our HDPE material page for details.

Typical downcycled products: plastic lumber, drainage pipe, non-food bottles (laundry detergent is frequently rHDPE), traffic cones, garden edging, and composite decking. Food-contact recycled HDPE exists in some jurisdictions but is less common than rPET because HDPE’s porous surface is harder to decontaminate.

Code #3 — PVC (Polyvinyl Chloride)

Polyvinyl chloride, PVC or simply vinyl, is the third most-produced plastic in the world and the one you almost never want to see in your recycling bin. It is rigid in its unplasticized form (pipes, window frames, credit cards) and flexible when mixed with plasticizers (medical tubing, shower curtains, wire insulation). PVC contains roughly 57 percent chlorine by weight — cheap to produce, problematic at end-of-life.

Common uses:

• Drain, waste, and vent pipes (residential plumbing)
• Window and door frames (uPVC)
• Vinyl flooring and wall cladding
• Blister packs for pharmaceuticals
• Shower curtains, inflatable toys, garden hoses
• Credit cards and ID cards
• Some cling film

Rigid PVC feels hard and dense, with a slight waxy sheen. Flexible PVC is soft, rubbery, and often has a faint chemical odor from plasticizer migration. Color ranges from translucent to opaque white to fully pigmented.

Recyclability score: low. Several closed-loop programs exist for construction offcuts (VinylPlus in Europe recycled over 800,000 tonnes in 2022), but post-consumer PVC is almost never accepted curbside. The chlorine content means that contamination of a PET or HDPE bale with even one or two PVC bottles can release hydrochloric acid during reprocessing, damaging equipment and ruining the batch. Sorting facilities treat PVC as a contaminant and remove it to landfill.

Typical downcycled products (from industrial streams only): new pipe, flooring underlay, traffic cones, garden hoses, and cable conduit. Consumer PVC almost always ends its life in a landfill or incinerator.

Code #4 — LDPE (Low-Density Polyethylene)

Low-density polyethylene, LDPE, is chemically almost identical to HDPE but has a branched molecular structure that prevents the chains from packing tightly. The result is a softer, more flexible, more transparent material that has become the default plastic for films, bags, and squeeze bottles. LDPE was the first polyethylene commercialized, invented by ICI in 1933.

Common uses:

• Plastic grocery and produce bags
• Bread and frozen food bags
• Squeeze bottles (honey, mustard, condiments)
• Shrink wrap and pallet wrap
• Dry cleaning and garment covers
• Flexible lids for coffee cans
• Six-pack ring holders

LDPE feels soft, waxy, and yielding. A thin film will tear cleanly in a straight line along its molecular orientation (which is how bread bags open). Squeeze bottles recover their shape slowly and can be crushed with one hand. The material is translucent but never fully clear, with a slight milky haze.

Recyclability score: medium-low. Rigid LDPE (squeeze bottles, container lids) is sometimes accepted in curbside programs alongside HDPE, but most LDPE in circulation is in the form of thin films — bags, wraps, and liners — which are not curbside recyclable anywhere. Thin films wrap around the spinning disks and shafts inside single-stream sorting equipment, causing costly shutdowns; they are the number one contaminant at most material recovery facilities.

The correct disposal route for clean LDPE film is the store drop-off programs found at grocery-store entrances in the US, UK, Australia, and parts of the EU. These bags go to specialized reprocessors who turn them into composite lumber (Trex decking is the best-known example), new plastic bags, or pellets for blown-film applications.

Typical downcycled products: composite lumber, trash bags, shipping envelopes, irrigation pipe, and plastic furniture.

Code #5 — PP (Polypropylene)

Polypropylene, PP, is a stiff, heat-resistant, increasingly popular plastic that sits in an interesting middle ground. Structurally it is closer to HDPE than PET, but its high melting point (around 160 °C) lets it do things neither can. PP is the only commodity plastic that reliably survives a domestic dishwasher, and it is the material of choice for hinges that need to flex millions of times without fatigue.

Common uses:

• Yogurt cups, margarine tubs, deli containers
• Bottle caps on almost all PET and HDPE bottles
• Medicine bottles for tablets and capsules
• Microwaveable containers and reusable lunchware
• Straws and disposable cutlery
• Automotive bumpers and interior trim
• Woven bags (rice, flour, pet food)

Polypropylene feels stiff but not brittle, with a matte, slightly waxy finish. It is typically opaque or translucent white, though pigments are common. A hallmark of PP is the “living hinge” — a thin section of material integrated into a container lid that bends tens of thousands of times without breaking. If your flip-top cap has one of those, it is almost certainly PP.

Recyclability score: medium. Historically PP had weak end markets and was often landfilled even when collected, but the last decade has seen rapid investment in dedicated PP sorting. The Polypropylene Recycling Coalition in North America and PureCycle’s molecular recycling process have raised PP rates meaningfully, though the material still trails PET and HDPE in infrastructure maturity.

Typical downcycled products: battery cases, paint cans, plastic pallets, signal lights, brushes, and textile fibers. Food-grade recycled PP is now available from producers using solvent-based purification, and the first rPP yogurt cups reached European shelves in 2023.

Code #6 — PS (Polystyrene)

Polystyrene, PS, comes in two very different forms that share the same recycling code. Solid polystyrene is hard, clear, brittle, and glass-like — disposable cutlery, CD jewel cases, the clear lid on a takeaway salad. Expanded polystyrene (EPS), better known by the trademarked name Styrofoam, is the familiar white foam used for coffee cups, packing peanuts, and coolers.

Common uses:

• Disposable cutlery, plates, and cups
• Takeaway clamshells and foam food trays
• Packing peanuts and electronics packaging
• Insulation board for construction
• CD and DVD cases
• Model-making foam

Solid PS is rigid and cracks cleanly — a plastic fork will snap rather than bend. EPS is almost entirely air (95-98 percent) with a characteristic squeaky feel when rubbed. Both forms have almost no chemical resistance; oils, citrus, and many solvents will dissolve them.

Recyclability score: very low. Polystyrene is one of the least-recycled commodity plastics. The solid form has weak end markets and is almost never accepted curbside. EPS is technically recyclable through densification, but curbside programs universally reject it because of its low density — a truck full of loose EPS weighs almost nothing and transporting it is economically unviable. Several US states and EU countries have banned EPS food-service packaging outright.

Typical downcycled products: picture frames, architectural molding, insulation, and new EPS packaging.

Code #7 — Other / Miscellaneous

Code #7 is the catch-all: “other resins and multi-material plastics.” It covers any plastic that is not one of the six commodity resins above, plus any object made from more than one polymer bonded together. This makes #7 the most ambiguous number on the scale — it tells you almost nothing about what you are holding.

Common uses:

• Polycarbonate (PC): reusable bottles, eyeglass lenses, DVDs
• Polylactic acid (PLA): compostable cups and cutlery from corn starch
• Nylon (PA): fishing line, some packaging films
• Acrylic (PMMA): display cases, light fittings
• Multi-layer laminates: juice pouches, toothpaste tubes, chip bags
• ABS: LEGO bricks, electronics housings

Physical properties are impossible to generalize — polycarbonate is hard and crystal-clear, PLA looks almost identical to PET but dents easily with a fingernail, and multi-layer films feel like any other plastic wrap. The defining feature of a #7 item is that you cannot tell what it actually is without additional markings or lab analysis.

Recyclability score: very low to none. Most #7 items are not recyclable through standard municipal programs. Multi-layer laminates (the largest category by volume) cannot be mechanically separated into their component resins and are either landfilled, incinerated, or sent to chemical recycling facilities that break them down into feedstock oils.

PLA deserves a note. It is often labeled “compostable,” and it is — but only in industrial composting facilities reaching sustained temperatures above 58 °C. In a home compost pile, a PLA cup will still be recognizable years later. In a recycling bin, it contaminates the PET stream because it looks identical to PET optical sorters but melts at a different temperature.

Typical downcycled products: few exist. Most #7 waste becomes refuse-derived fuel, landfill, or feedstock for emerging chemical recycling plants.

Common Misconceptions About Codes

“The triangle means it’s recyclable.” No. The triangle is a resin identification code. It identifies the polymer so that industrial sorters know what they are handling. Whether an item is actually recycled depends on local infrastructure, market prices, and contamination — not on the code.

“All plastics with the same number are recycled together.” Only partially true. A code #1 PET bottle and a code #1 PET clamshell are the same polymer, but thermoforming produces a slightly different crystalline structure, and many recyclers reject clamshells because they contaminate bottle streams.

“Bioplastics are better because they’re #7 and compostable.” Only if they reach an industrial composting facility, which in most countries serves fewer than 10 percent of households. In landfill, PLA decomposes anaerobically and releases methane — a worse climate outcome than conventional PET sitting inert.

“If I can’t tell the number, I should put it in the bin anyway.” This is “wishcycling,” and it is a serious problem. Contamination rates above 20 percent can render entire bales unsaleable. When in doubt, throw it out.

“Higher numbers mean more recyclable.” The numbers are not a hierarchy. Codes #1 and #2 happen to be the most recyclable; codes #3, #6, and #7 are among the least. The numbers themselves carry no ranking information.

Which Plastics Actually Get Recycled?

Globally, the numbers are sobering. According to the OECD’s 2022 Global Plastics Outlook, only about 9 percent of plastic waste is recycled, 19 percent is incinerated, 50 percent goes to sanitary landfill, and 22 percent is mismanaged. Among the recycled fraction, PET and HDPE account for the overwhelming majority.

In practical terms:

• Reliably recycled (worldwide): PET bottles (#1) and HDPE bottles and jugs (#2), especially in regions with deposit-return schemes.
• Sometimes recycled (depends on location): PP (#5) where dedicated programs exist; LDPE (#4) rigid items; clean industrial PVC (#3) offcuts.
• Rarely recycled: LDPE films, polystyrene (#6), code #7 multi-layer packaging, PLA, colored PET clamshells.

The gap between what is theoretically recyclable and what actually gets recycled is one of the central issues in modern waste policy. For consumers, the most effective action is upstream: reducing single-use plastic consumption. For those who must buy plastic, codes #1 and #2 offer the best chance of a genuine second life.

Frequently Asked Questions

1. If a plastic item has no recycling code, can I still recycle it?

Generally no. Items without a resin identification code cannot be reliably sorted by material recovery facilities and should go in general waste. Some jurisdictions accept uncoded rigid plastic in a “mixed plastics” stream, but most do not.

2. Is the plastic in compostable cups really better for the environment?

Only if it actually reaches an industrial composting facility. Polylactic acid (PLA) cups require sustained temperatures above 58 °C to break down, which home composters cannot provide. In landfill, PLA generates methane; in a recycling bin, it contaminates the PET stream. If your area lacks industrial composting, conventional #1 PET is often the more honest choice.

3. Can I recycle plastic bottle caps?

Yes — and modern guidance is to leave them screwed onto the bottle. Most caps are polypropylene (#5) while bottles are PET (#1) or HDPE (#2), and sorting facilities separate them automatically during the float-sink process (PP floats, PET sinks). Loose caps are too small to sort and fall through screens.

4. What does the letter after the number mean? (PET vs PETE, PVC vs V)

Nothing meaningful. PET and PETE are the same polymer — PETE was introduced in the 1990s because some markets confused PET with the company name Pet Inc. V is simply vinyl, used interchangeably with PVC. LDPE is sometimes written PE-LD in ISO notation. All are identical in practice.

5. Why are so many items made of #7 plastic if it isn’t recyclable?

Because #7 covers every engineered, high-performance, or multi-layer plastic outside the six commodity resins. Manufacturers choose these materials for barrier properties, durability, or cost — not for end-of-life. Closing this loop is the biggest opportunity for chemical recycling and mono-material redesign.

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Sources: Society of the Plastics Industry (SPI), 1988 Resin Identification Code specification; ASTM International, ASTM D7611/D7611M Standard Practice for Coding Plastic Manufactured Articles for Resin Identification; OECD Global Plastics Outlook 2022; Plastics Industry Association (PLASTICS). Last reviewed 2026-04-11.