Plastic Categories Explained (and How to Recycle Them Properly)

Plastic recycling can feel confusing — even when you’re genuinely trying to do the right thing. That’s why having plastic categories explained is so important. Symbols, numbers, mixed messages from councils, and packaging labelled “recyclable” that still ends up in landfill can make the whole process frustrating.

This guide breaks down the seven main plastic categories, explains what those numbers actually mean, and shows you how to recycle plastic properly in the UK — without wishcycling or guilt. Most importantly, it also looks at how we can reduce plastic use in the first place, because recycling should always be the last resort.

What are plastic resin codes?

Most plastic packaging is marked with a small triangle made of arrows, containing a number from 1 to 7. These are called plastic resin identification codes.

They tell manufacturers (and recycling facilities) what type of plastic the item is made from, not whether your local council will collect it. That’s a crucial distinction — and the reason so much plastic still gets mis-sorted.

There are seven main types of plastic commonly used in household products, each with different recycling challenges and environmental impacts.

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The most commonly recycled plastics

The following plastics are generally the most valuable and in-demand for recycling facilities in the UK — although local rules still apply.

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1. PET – Polyethylene Terephthalate (Plastic #1)

Common uses

• Water and fizzy drink bottles
• Food trays
• Salad containers

Recycling notes PET is one of the easiest plastics to recycle and has strong market demand. It’s lightweight, airtight, and widely accepted by UK councils.

Zero waste tip Choose refillable bottles or larger containers where possible, and avoid single-use drinks when you can.

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2. HDPE – High Density Polyethylene (Plastic #2)

Common uses

• Milk bottles
• Shampoo and cleaning product bottles
• Detergent containers

Recycling notes HDPE is highly recyclable and commonly turned into new bottles, pipes, and plastic lumber.

Zero waste tip Refill schemes for cleaning products are an excellent way to cut down on HDPE waste.

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3. LDPE – Low Density Polyethylene (Plastic #4)

Common uses

• Plastic carrier bags
• Bread bags
• Bin liners
• Soft plastic wrapping

Recycling notes LDPE is not usually collected in household recycling bins, but many large supermarkets now accept it at in-store soft plastic recycling points.

Zero waste tip Reuse bags where possible, and take all clean soft plastics back to supermarkets instead of binning them.

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4. PP – Polypropylene (Plastic #5)

Common uses

• Margarine and yoghurt tubs
• Ready-meal trays
• Medicine containers

Recycling notes PP has a high melting point, making it suitable for hot foods. It is increasingly accepted by UK recycling facilities, though not universally.

Why it matters When recycled, PP can become items like:

• Battery cases
• Storage bins
• Garden tools
• Signal lights

This makes it well worth rinsing and recycling properly.

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Plastics that are harder to recycle

These plastics can sometimes be recycled, but they are more problematic due to additives, chemical structure, or lack of demand.

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5. PVC – Polyvinyl Chloride (Plastic #3)

Common uses

• Food packaging
• Pipes
• Window frames

Recycling notes PVC is difficult to recycle and rarely accepted in household recycling. It contains additives that complicate processing.

Zero waste tip Where possible, avoid PVC packaging altogether and look for alternative materials.

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6. PS – Polystyrene (Plastic #6)

Common uses

• Disposable cutlery
• Yogurt pots
• Protective packaging

Recycling notes Polystyrene is lightweight but bulky, making it costly to transport and recycle. Most councils do not accept it.

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7. Other – Mixed or Composite Plastics (Plastic #7)

Common uses

• Multi-layer food packaging
• Baby bottles
• Some reusable containers

Recycling notes This category includes mixed plastics that are extremely difficult to separate and recycle. These often end up in landfill.

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What the numbers don’t tell you

This is where many well-meaning recyclers get caught out.

• A plastic can be recyclable, but not accepted locally
• Labels, food residue, and mixed materials can make items unrecyclable
• Black plastic often isn’t detected by sorting machines
• “Biodegradable” or “compostable” plastics do not belong in recycling

Putting the wrong items in your recycling bin can contaminate an entire load — meaning nothing gets recycled.

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Zero Waste Llama’s tips for recycling plastic properly

✅ Empty and rinse containers

Leftover food can contaminate paper and card in the same load. A quick rinse is enough — no need to scrub.

✅ Leave lids on bottles

Small loose items often fall through sorting machines. Screwing lids back on helps them stay together.

✅ Squash bottles

This saves space in your bin and stops bottles rolling off conveyor belts at recycling facilities.

✅ Recycle soft plastics at supermarkets

Soft plastic recycling points can increase how much household plastic you recycle by up to 10%.

Accepted items often include:

• Bread and cereal bags
• Crisp and sweet wrappers
• Bubble wrap
• Salad, pasta, and rice bags
• Toilet roll wrapping

(Always check signage in-store, as acceptance varies.)

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Check your local recycling rules

Recycling rules vary widely across the UK. The easiest way to check what you can recycle is to:

• Visit Recycle Now
• Or use your local council’s recycling checker

Enter your postcode to see exactly what’s accepted where you live.

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Reduce first, recycle second

Recycling is important — but it’s not a perfect solution. Many plastics are downcycled, exported, or discarded due to contamination.

The most effective actions you can take are:

1. Reduce unnecessary plastic (see Shopping Plastic Free)
2. Reuse what you already have
3. Recycle what you can correctly

Small, consistent changes really do add up.

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Final thought

Understanding plastic categories empowers you to recycle more effectively and make better choices at the shop. If this guide helped you, consider bookmarking it or sharing it — the more people who recycle correctly, the more effective the system becomes.

Shopping Plastic Free

TerraCycle® – The First European Pet Food Recycling Programme