Look around your home or in the kitchen and take a closer look at some everyday plastic products. Almost every one of them will be labeled with a triangle “♻” and a number “1-7”. These symbols are used to help identify the properties and chemical composition of the plastic involved in making that product.
Not all plastics are made the same way, so recycling operations rely on these labels to determine the best way to reuse and reproduce plastic goods. As a consumer, understanding how different plastics are made can help you be a more effective recycler at home.
♻ #1: PET (Polyethylene Terephthalate)
PET is made from thermoplastic resin that makes up most of the plastic bottles in circulation today and is the most recycled plastic on this list.
According to the National Postconsumer Plastic Bottle Recycling report of 2018, out of all the plastic recovered for recycling in the US, 97% of that plastic was PET and HDPE grade plastic.
Its flexibility, water resistance, and durability make it affective for temporary food storage. Its polymer chains are also stable, which is what keeps its components from leaching into food at room temperature.
- Soft drink bottles
- Polyester
- Fruit containers
- Cooking oil containers
- Synthetic fibers
- Cosmetics
♻ #2: HDPE (High-Density Polyethylene)
HDPE is the thicker and tougher version of PET. Like PET, HDPE is a thermoplastic that comes from polymerizing the ethylene gas released from super-heated petroleum.
Due to its stable molecular structure, this grade of plastic is incredibly resistant to damage from insects, rot, and chemical alteration. This makes HDPE ideal from containing harsh chemicals or cleaning supplies.
HDPE is 100% recyclable when properly rinsed out and is the second most postconsumer recycled plastic on this list.
- Cleaning agents
- Soap bottles
- Shampoo bottles
- Bleaching agents
- Detergents
♻ #3: PVC (Polyvinyl Chloride)
PVC is the 3rd most widely used in the US, which can be attributed to its versatile use for construction, food, and textile industries. PVC is fire resistant and highly ridged, making it a suitable material for plumbing pipes and windowsill inserts.
To make PVC more malleable plasticizing additives may be added during its production, however; additives exceeding 50% of PVC’s total composition may result in an unstable product. PVC plastic is made from polymerizing toxic and carcinogenic gasses which must be handled under special protective procedures.
PVC is recyclable but at temperatures above 212F PVC degrades into hydrogen chloride, which is toxic if inhaled or consumed. With that in mind, recycled PVC plastics are reserved for products unrelated to consumables.
- Food wrapping
- Fast food drink cups
- Garden hoses
- Polyester
- Plumbing Pipes
- Imitation leather
♻ #4: LDPE (Low-Density Polyethylene)
LDPE is the thinner version of PET. LDEP is another thermoplastic resin made from superheating petroleum. The difference in LDPE from its cousins lies in its loosely packed polymer chains, resulting in a highly flexible substance that is less prone to stress fractures. LDPE makes up most of the plastic bags available at supermarkets.
- Most wrappings
- Shopping bags
- Weather-resistant textiles
- Sheet goods
♻ #5: PP (Polypropylene)
Polypropylene plastic is a polymerization resin made from superheated ethane, propane, butane, and the naphtha fraction od petroleum. While there is a growing reclamation infrastructure in the US, PP made up about 1.8% of all post-consumer plastics recovered for recycling in 2018.
Because of its low conductivity and its high melting point of around 320 degrees F, PP is ideal for electrical components and dishwasher-safe food containers. It can also be dyed different colors without degrading the substance’s quality, making it ideal for the toy industry.
- Window liners and external borders for cars
- Toys
- Furniture
- Luggage
- Dishwasher-safe food containers
♻ #6: PS (Polystyrene)
Polystyrene is a ridged polymerized resin with many applications for food and construction industries. Its most common form exists as Styrofoam packaging or it can be hardened into plastic utensils.
styrofoam is a form of polystyrene that has been foamed up using carbon dioxide and lightweight. Its lightweight nature makes it ideal as packing material, but this is also what makes it the most brittle plastic on this list. Polystyrene is also highly flammable, making it difficult to recycle but not impossible.
Polystyrene cups and packing material can be recycled into foam insulation in homes, but PS makes up less than 1% of recovered plastic. The sheer volume needed to produce viable products from recycled polystyrene also makes the process of separating and processing polystyrene not worth the money energy required to do so.
- Refrigerators trays
- Food trays
- Cosmetic bags
- Egg cartons
- Eating utensils
- Compact disk cases
♻ #7: OTHER
This category is for plastics that do not belong to the previous categories. Plastics that belong to this category include PLA (polylactic acid), Fiberglass, nylon, and most commonly, PC (polycarbonate) plastics.
Plastics that find themselves in this misfit category might be separated and sent to a more specialized recycling facility. More commonly, plastics that fall into this mystery category will end up at the nearest landfill or incinerated for energy.
- Polylactic
- Fiberglass
- Nylon
- Polycarbonate plastic