What Do the 7 Plastic Recycling Numbers Mean?

If you look at the bottom of a plastic container, tote, bottle, bucket, or other plastic product, you may notice a small triangle containing a number from 1 through 7. These numbers are commonly called plastic recycling numbers, resin identification codes, or simply plastic numbers.

While many people assume the number tells them whether an item can be recycled, that isn’t exactly what it means.

Plastic recycling numbers primarily identify the type of plastic resin used to manufacture a product. Understanding these numbers can help consumers, manufacturers, warehouses, distribution centers, and other businesses determine what kind of plastic they’re handling and what recycling options may be available.

For companies generating significant amounts of plastic scrap, identifying the resin can be particularly important. Different plastics have different properties, applications, recycling processes, and potential values in the secondary plastics market.

Here is what plastic recycling numbers 1 through 7 mean.

What Are Plastic Recycling Numbers?

The numbers found on plastic products are part of the Resin Identification Code (RIC) system.

The system separates commonly used plastics into seven categories:

1. PET or PETE – Polyethylene Terephthalate
2. HDPE – High-Density Polyethylene
3. PVC – Polyvinyl Chloride
4. LDPE – Low-Density Polyethylene
5. PP – Polypropylene
6. PS – Polystyrene
7. Other – Plastics that don’t fit into categories 1–6

One important distinction is that the recycling symbol and resin identification code do not guarantee that a plastic product is recyclable through your local recycling program.

The number identifies the resin. Whether the material can actually be recycled depends on factors such as local recycling infrastructure, contamination, product construction, volume, color and available markets for the recovered material.

Industrial recycling is also very different from residential curbside recycling.

Manufacturers can generate thousands of pounds of relatively clean and consistent plastic scrap. That material may have recycling opportunities that would not exist for a small quantity of the same plastic placed into a household recycling bin.

Plastic #1: PET or PETE – Polyethylene Terephthalate

Plastic recycling number: 1

Material: Polyethylene terephthalate

PET is one of the most recognizable plastics because it is widely used for bottles and packaging.

Common PET products include:

• Water bottles
• Soft drink bottles
• Food containers
• Clear packaging
• Certain industrial packaging
• Polyester fibers and materials

PET is lightweight, strong and capable of creating transparent containers, making it particularly useful in the food and beverage industries.

Recovered PET can be processed into materials used for new containers, fibers, textiles, strapping and other products.

For industrial operations, separating PET from other resin types helps maintain a more consistent recycling stream.

Plastic #2: HDPE – High-Density Polyethylene

Plastic recycling number: 2

Material: High-density polyethylene

HDPE is one of the most important plastics used in both consumer and industrial applications.

It is known for its combination of strength, durability, chemical resistance and relatively low weight.

Common HDPE products can include:

• Bottles
• Buckets
• Drums
• Industrial containers
• Crates
• Plastic pallets
• Bins
• Totes
• Pipe
• Injection-molded components
• Blow-molded products

HDPE is particularly important in industrial plastic recycling because manufacturers and distribution operations can generate substantial quantities of relatively consistent HDPE material.

Production scrap may include defective parts, runners, purge, containers, damaged products, off-spec material and other manufacturing remnants.

When properly sorted and kept reasonably clean, HDPE can often be processed into regrind or pellets for use in subsequent manufacturing applications.

Plastic #3: PVC – Polyvinyl Chloride

Plastic recycling number: 3

Material: Polyvinyl chloride

PVC is a versatile plastic frequently associated with construction materials.

Common applications include:

• Plumbing pipe
• Vinyl siding
• Flooring
• Cable insulation
• Construction products
• Medical products
• Flexible vinyl materials

PVC can be manufactured as either a rigid or flexible material depending on its formulation.

Recycling PVC can be more complicated than recycling some commodity plastics because formulations can contain different additives, plasticizers and other compounds.

For industrial generators, accurately identifying PVC and keeping it separated from incompatible plastics can be important when establishing a recycling program.

Plastic #4: LDPE – Low-Density Polyethylene

Plastic recycling number: 4

Material: Low-density polyethylene

LDPE belongs to the polyethylene family but has different physical characteristics from HDPE.

Where HDPE is generally associated with more rigid products, LDPE is commonly found in flexible applications.

Examples include:

• Plastic film
• Bags
• Packaging film
• Liners
• Stretch film
• Certain flexible containers
• Protective packaging

Industrial facilities, warehouses and distribution centers can generate large amounts of LDPE film.

Clean commercial film that is separated from labels, food, dirt, paper and incompatible materials may offer considerably better recycling opportunities than heavily contaminated mixed film.

Businesses generating large volumes of LDPE can often improve material handling by consolidating or baling the film before transportation.

Plastic #5: PP – Polypropylene

Plastic recycling number: 5

Material: Polypropylene

Polypropylene is another major industrial plastic.

PP is lightweight, durable and resistant to many chemicals. It also performs well in applications where repeated bending or flexing is required.

Common polypropylene products include:

• Automotive components
• Crates
• Totes
• Bins
• Buckets
• Caps and closures
• Packaging
• Injection-molded parts
• Industrial components

Manufacturing processes can generate polypropylene scrap in several forms, including runners, defective parts, purge, off-spec products and production remnants.

Like HDPE, PP can be particularly attractive for industrial recycling programs when the resin is properly identified, separated and accumulated in sufficient volume.

Plastic #6: PS – Polystyrene

Plastic recycling number: 6

Material: Polystyrene

Polystyrene can appear as either a rigid plastic or a lightweight foam.

Common examples include:

• Protective packaging
• Foam packaging
• Disposable food containers
• Insulation
• Rigid plastic products
• Laboratory products

Expanded polystyrene is extremely lightweight relative to its volume, which can make transportation economics challenging.

A truck filled with lightweight foam may contain relatively little actual plastic by weight.

Industrial recycling opportunities can therefore depend heavily on volume, density, cleanliness and access to appropriate processing equipment or end markets.

Plastic #7: Other

Plastic recycling number: 7

Number 7 is essentially a catch-all category.

It can include plastics that aren’t represented by numbers 1 through 6 as well as certain multilayer or specialty materials.

Examples can include:

• Polycarbonate
• Acrylic/PMMA
• Nylon
• ABS
• PLA
• Certain engineered plastics
• Multilayer materials

This makes identifying a number 7 plastic more complicated.

Two products marked with a 7 may be made from completely different materials.

Industrial generators should therefore avoid assuming all number 7 plastics can be combined. Manufacturer specifications, resin markings, technical data sheets or testing may be needed to determine the actual material.

Which Plastic Recycling Numbers Are Recyclable?

There isn’t a universal answer.

A resin identification number tells you what type of plastic something is, not whether your municipality or a particular recycler accepts it.

Recyclability can depend on:

• Resin type
• Product design
• Contamination
• Color
• Additives
• Fillers
• Labels
• Metal components
• Mixed materials
• Quantity
• Transportation costs
• Regional processing capacity
• Current markets for recycled resin

This distinction becomes especially important for industrial plastic.

A consumer might have one polypropylene container. A manufacturer could have 20,000 pounds of clean polypropylene production scrap.

Those are very different recycling scenarios.

Why Plastic Type Matters for Industrial Recycling

One of the most important steps in establishing an industrial plastic recycling program is identifying and separating material correctly.

Imagine a manufacturer generating:

• HDPE parts
• PP runners
• ABS components
• LDPE film

Throwing everything into one container creates a mixed-plastic stream that can be much harder to process.

Separating the materials at the point where they’re generated can create four cleaner, more identifiable streams instead.

That can improve recycling efficiency and potentially increase the usefulness or value of the recovered plastic.

What Forms of Industrial Plastic Can Be Recycled?

Industrial plastic isn’t always generated as finished products.

Manufacturing and distribution facilities may accumulate material in forms such as:

Purge: Hardened plastic generated during equipment cleaning, material changes or production processes.

Runners and sprues: Excess material created during injection molding.

Regrind: Plastic that has already been mechanically reduced into smaller pieces.

Off-spec parts: Products that don’t meet manufacturing specifications.

Totes and bins: Damaged or obsolete reusable material-handling containers.

Crates: Shipping and distribution containers that have reached the end of their usable life.

Pallets: Broken or retired plastic pallets.

Film: Stretch wrap, packaging film and other flexible polyethylene materials.

Whether these materials can be recycled depends on resin, contamination, volume and other factors.

How Can a Business Identify Unknown Plastic?

Finding a resin identification code is a good starting point, but industrial products aren’t always marked.

Businesses can also check:

• Product specifications
• Purchase records
• Supplier documentation
• Safety or technical data sheets
• Mold markings
• Resin certifications
• Original manufacturing records

If significant quantities of material are involved, recyclers or laboratories may also be able to help determine the resin.

Correct identification becomes increasingly important when multiple plastics look similar.

For example, an HDPE component and a polypropylene component may look nearly identical even though they are different polymers.

Should Different Plastic Numbers Be Mixed Together?

Generally, separating plastics by resin is preferable.

Different polymers have different melting temperatures, densities, processing characteristics and chemical structures. Combining incompatible materials can reduce the quality of recovered plastic.

Businesses can make recycling easier by establishing designated containers for different materials.

For example:

Container A: HDPE
Container B: PP
Container C: ABS
Container D: LDPE film

Employees can then sort scrap where it is generated instead of attempting to separate a large mixed pile later.

Plastic Recycling Numbers Are Really Material Identification Numbers

Perhaps the biggest misconception surrounding numbers 1 through 7 is that they represent a simple recyclability scale.

They don’t.

A #1 doesn’t necessarily mean “easy to recycle,” and a #7 doesn’t automatically mean “impossible to recycle.”

The numbers primarily tell you which category of plastic you’re dealing with.

For manufacturers and other businesses generating large amounts of plastic scrap, that information can be the first step toward developing a more effective recycling program.

Seraphim Plastics works with businesses generating qualifying volumes of post-industrial plastic materials, including materials such as HDPE, polypropylene and LDPE, as well as a range of other industrial plastics.

Understanding exactly what resin your company generates—and keeping those materials properly separated—can help turn what appears to be manufacturing waste into a usable material stream.