Recycling codes: 1 for PET, 2 for HDPE, 5 for PP
Turn a bottle over: under its base, a small triangle surrounds a number. Many read it as a promise of recycling. The number says something else, and that is already a lot: the material the bottle is made of.
By Tecmom editorial team · 2 min read
A material code, not a recycling code
These numbers are resin identification codes. In the United States, the ASTM D7611 standard governs them and says so plainly: they are used solely to identify the resin of an item. They are not "recycle codes", and their presence implies neither that the item is recycled nor that a system exists to recycle it.
They remain valuable for sorting centres and recyclers, who read the material, and therefore its behaviour, from them. It was to remove the ambiguity that ASTM replaced the chasing arrows with a plain solid triangle.
The seven families
The most widespread numbering has seven codes:
- PET, polyethylene terephthalate: clear or amber bottles;
- HDPE, high-density polyethylene: opaque bottles, cans;
- PVC, polyvinyl chloride;
- LDPE, low-density polyethylene: films, squeezable bottles;
- PP, polypropylene: caps, pill containers, tubs;
- PS, polystyrene;
- Other, including items made of several resins.
In Europe
In 1997 the European Union adopted an identification system for packaging materials, Decision 97/129/EC, voluntary in use, which takes the same numbers 1 to 6 for plastics. Regulation (EU) 2025/40 on packaging repeals it, with effect in 2028, and provides instead for harmonised labelling of packaging composition to make sorting easier.
What to remember
The number answers the question "what is it made of?". The question "can it be recycled?" depends on something else: the material, but also whether collection and a recycling route exist where the pack is thrown away.
To compare the three materials of our bottles, pill containers and caps, see our advice page HDPE, PET, PP, and on recycling, recycled PET.
The triangle under a bottle is not a promise; it is an identity card. And for a pack to be recycled, one must first know what it is made of: that is exactly what this small number says.
Glossary
- Resin identification code
- A number from 1 to 7 that indicates the plastic of an item.
- HDPE
- High-density polyethylene, code 2.
- LDPE
- Low-density polyethylene, code 4.
- Recycling route
- The whole chain of collection, sorting and recycling for a material.