Have you ever wondered what the number codes inside the "Recycling triangle" on the bottoms of plastic containers indicate? Well, it tells you the material that the container is made from.
The codes and materials are:
1 - Polyethylene Terephthalate (PET)
2 - High Density Polyethylene (HDPE)
3 - Polyvinyl Chloride (PVC)
4 - Low Density Polyethylene (LDPE)
5 - Polypropylene (PP)
6 - Polystyrene (PS)
7 - Other Plastics
The material in which it is made of actually determines how recycling may occur. For instance, many recycling operations will not accept Code 7 material, because the wide variety of plastics makes recycling difficult.
Plastics coded 1 and 2 are recycled the most (Ref 2). Other less recyclable plastics are polyvinyl chloride (PVC - code 3), low-density polyethylene (LDPE code 4), polypropylene (PP - code 5), polystyrene (PS - code 6) and any other plastic (code 7).