Guide one
Reading the PP Mark
The small triangle moulded into a plastic item is a resin identification code. Learning to read it takes a minute and makes sorting, reusing and buying a little easier.

What the triangle means
The code identifies the type of plastic resin an item is mainly made from. It was introduced in the late 1980s to help recyclers sort material, and today it is maintained as an international standard. In 2013 the familiar chasing arrows were changed, in the standard, to a solid triangle, because the arrows led many people to believe that every marked item could be recycled. Both versions are still seen on products.
A number in a triangle never means “recyclable here”. It tells you the material. Your local scheme decides what it collects.
The seven codes
| Code | Letters | Material | Everyday examples |
|---|---|---|---|
| 1 | PET or PETE | Polyethylene terephthalate | Drink bottles, fruit punnets |
| 2 | HDPE | High-density polyethylene | Milk jugs, detergent bottles |
| 3 | PVC or V | Polyvinyl chloride | Pipes, cable sheathing, some blister packs |
| 4 | LDPE | Low-density polyethylene | Carrier bags, bread bags, film wrap |
| 5 | PP | Polypropylene | Yoghurt pots, food tubs, caps, straws, microwave trays |
| 6 | PS | Polystyrene | Foam trays and cups, some pots, disposable cutlery |
| 7 | O or OTHER | Other plastics and mixtures | Polycarbonate, acrylic, multi-layer films |
Where to look
- Tubs and pots: on the base, often near the mould number.
- Lids: on the inside face. A lid and its tub can be different plastics.
- Bottle caps: under the rim, sometimes very small.
- Bags and sacks: printed near a seam or on a label.
- Car and appliance parts: moulded letters such as >PP< or >PP-T20<, where the extra letters show a filler.
Other marks you may see next to it
| Mark | What it usually tells you |
|---|---|
| Glass and fork | The item is intended for contact with food. |
| Wavy lines or a microwave outline | The maker says it is suitable for microwave use, under their conditions. |
| Snowflake | The maker says it is suitable for the freezer. |
| Dishes under water drops | Dishwasher suitability, sometimes “top rack only”. |
| rPP or a percentage | The item contains recycled polypropylene. |
Telling PP from look-alikes
Without a mark it is hard to be sure. PP and polyethylene both feel slightly waxy and both float in water, while PET and polystyrene sink. PP tends to be stiffer than polyethylene and can be bent back and forth many times without snapping, which is why it is used for the thin “living hinge” on flip-top caps. When in doubt, treat an unmarked item as unknown rather than guessing.