09/30/2025
PDX-Earth Tip: Can this be recycled? Is this recyclable? Can I put this in the recycling bin?
No more common words are uttered these days that those associated with the confusion surrounding plastic recycling, even though recycled plastic has been a going concern for decades. But even with all the labelling and upgrades in the effort to keep plastic out of the pollution pipeline, it’s worth taking a moment to review where we are – and how we got here.
The little triangle on the bottom of plastic bottles, tubs, containers and trays is called a “Morbius Loop,” and was designed in conjunction with the inaugural Earth Day in 1970 to help lend a graphic edge to recycling. Gary Anderson, a 23-year-old university student in North Carolina, won a nationwide contest with his universal recycling symbol, which now graces millions and millions of household items.
But inside each Morbious Loop is a number, and that’s where it gets complicated. Bottom-line, there are seven types of plastics. Generally, most recyclers accept plastics #1 and #2. Plastics #3 to #6 are more difficult to recycle, and some recycling centers do not process them. Plastic #7 is even more challenging to recycle and is almost always excluded.
Number 1 is polyethylene terephthalate (PET), one of the most common polymers in the polyester family whose global market size was estimated to be worth over $40 billion in 2024. PET is used in applications such as textile fibres, bottles, rigid/flexible packaging, and electronics and accounts for 12% of all global solid waste, yet PET bottles are only estimated to have a 28% recycling rate in residential systems.
So here’s a couple of tips: Water bottles and plastic soda bottles are the most common containers made out of PET and they are OK to recycle. But avoid reusing plastic containers made of PET because it’s meant for single-use and repeated use increases the risk of leaching carcinogens and bacterial growth.
The Number 2 category is most milk jugs, detergent containers, and oil bottles all made from High Density Polyethelene (HDPE). It’s a very common plastic and one of the safest to use. It’s also fully recyclable.
From 3 to 7, it gets slippery. Number 3 is reserved for Polyvinyl Chloride (PVC), which is used for plastic food wrapping because it’s soft and flexible. Most recyclers will not take PVC products and avoid reusing PVC products because they leach toxins.
Number 4 is Low-Density Polyethylene, which is essentially plastic bags. These products are so difficult to recycle and cause such environmental damage that you increasingly see them banned.
Polypropylene dominates number 5 and is reserved for margarine tubs, cottage cheese tubs, and yogurt containers. It is difficult to recycle and can break down and leach toxins over time.
Numbers 6 and 7 are essentially the no-go plastics like styrofoam and should be avoided at all costs.
For more, visit kpsu.org.
