The last code of the plastic resin identification is code 7. This refers to any other types of plastic that do not belong to the other six resins: PETE (1), HDPE (2), PVC (3), LDPE (4), PP (5), and PS (6).
Plastic resin identification code number 7 is for any other types of plastic resin except the six above. It can also be to refer to combination of plastic resins, such as acrylonitrile butadiene styrene. Others are like fiberglass, nylon, polycarbonate, polyactic acid, and PMMA. Like the other 6 resins, the code is usually imprinted at the bottom of any plastic goods. If you can’t find any recycling plastic resin identification code, it is considered to belong to the 7th category.
Summary of all plastic resin codes:
I’d like to define safety based on two things: food-related and environment-related.
The plastic resins that are safe for food applications, as discussed before, are PETE, HDPE, LDPE, PP and PS. Each has its own limitation, like some need to be disposed immediately after their first use, and some others are reusable. Read the articles about each resin as linked above. PVC and others (7) are not safe for food as they might release toxin to the foods.
Environment-related safety refers to the recyclability of each resin. Most recycling stations accept PETE and HDPE since they are the most economical one in terms of recycling; but the others may be accepted too. Check with your local curbside programs which resins they can handle. PVC and the plastic resin number 7 are probably the hardest and the most expensive to recycle. Code 7 is even said to be almost impossible to recycle at all due to the complexity of the elements.
Which plastic types are you going to use? And what do you do to them as soon as you are done using them? For the sake of our future children, let’s start recycling from now on: reduce, recycle and reuse.