Plastics 101: The Recycling Process

We look at the bottom of our plastics in search for a code number 1 through 7. This code, as previously explained in last month’s post, identifies the type of plastic resin. It also facilitates the recycling process as the type of resin an item is made of limits the products it can recycled into. For a printable list of resin codes, click here.

How are plastic resins recycled?  There are five basis steps to the Recycling Process (sometimes referred to as down-cycling):

1. Sorting – After plastic is collected by the recycling company, it is sorted by resin type.
2. Washing – Plastic items are cleaned of all adhesives and labels. You can help make this job easier and cheaper for recycling companies by doing the bulk of this process yourself.
3. Shredding – Plastic is shredded by large machines and made into small pellets.
4. Identification and Classification – So far, the plastic has been identified by the eye alone. Now, the small pellets are chemically tested to ensure accurate classification.
5. Extruding – Finally, the plastic is melted and extruded into clean, properly identified pellets. (note, often the plastic resin is still not 100 percent pure)

The plastic is then sold or used to fill orders to manufacturers who create the new plastic product. Here is a list of the seven types of commonly used plastics and what they are frequently recycled into.

1. Polyethylene Terephthalate (PETE or PET)
First developed in 1957, the more commonly known name for this type of plastic is polyester. You can find PETE in the following items:

• Nylon and polyester clothes
• Bed sheets
• Cosmetics
• Household cleaners
• Upholstered furniture
• Water and Condiment bottles
• Jelly and Peanut Butter Jars

PROS: Not known to leach chemicals, unless it contains BPA
CONS: Some studies have found that antimony is leached from water bottles made from PETE after prolonged use in heat; BPA has been linked to breast and uterine cancer

Commonly Recycled Into: Tote Bags, Furniture, Carpet, Paneling, Fiber, and Polar Fleece

2. High Density Polyethylene (HDPE)
Along with PETE, it is the most commonly used and versatile of plastics. HDPE resists UV rays, can tolerate high temperatures, and is dishwasher safe. It is found in a variety of items:

• Landry detergent bottles
• Milk jugs
• Folding Chairs and tables

PROS: Not known to leach chemicals, no known health concerns.

Commonly Recycled Into: Pens, Recycling Containers, Picnic Tables, Lumber, Benches, Fencing, Detergent Bottles, Crates, Garden Products, Office Products, Automobile Parts[i]

3. Polyvinyl chloride (V or PVC)
PVC might be the most difficult plastic to recycle, next to 7. It is incredibly durable and resists impurities, but it is also the most chemically dangerous. PVC can be found in the following items:

• Shower Curtains
• Cling wrap
• Clothing
• Inflatable structures
• Waterbeds
• Pool toys
• Car interiors
• Vinyl flooring

CONS: Known to leach chemicals, SHOULD BE AVOIDED[ii]; Not as widely recycled as 1 or 2

Commonly Recycled Into: Paneling, Flooring, Speed Bumps, Decks, and Roadway Gutters

4. Low-density polyethylene (LDPE)
This type of plastic was created in 1954. Polypropylene is excellent at withstanding heat. Research is mixed regarding the safety of polypropylene. Regardless, it is used in much of our plastic food packaging:

• Bread and frozen food bags
• Packaging material
• Plastic grocery bags
• Squeezable bottles

PROS: Not known to leach chemicals
CONS: Not as widely recycled as 1 or 2

Commonly Recycled Into: Compost Bins, Paneling, Trash Cans and Liner, Floor Tiles, Shipping Envelopes

5. Polypropylene (PP)
A very strong plastic with a high melting point, it is a likely candidate for reusable food containers such as:

• Yogurt and margarine containers
• Plastic cups
• Baby Bottles
• Kitchenware, microwavable plastic containers and lids2

PROS: Recycling becoming more common; dangerous during production process, but not known to leach any chemicals after the fact. Dishwasher safe
CONS: Not as widely recycled as 1 or 2

Commonly Recycled Into: Brooms, Auto Battery Cases, Bins, Pallets, Signal Lights, Ice Scrapers, and Bicycle Racks, Flower pots

6. Polystyrene (PS)
This plastic can be converted into either foam, made 97 percent of air, or a tougher, yet brittle substance like that used for CD cases. Here are some of the items PS is found in:

• Foam Insulation
• Disposable cutlery
• CD and DVD cases
• Egg Cartons
• Foam Cups & To-Go Foam from restaurants

CONS: According to the Foundation for Achievements in Science and Education fact sheet, long term exposure to small quantities of styrene can cause neurotoxic (fatigue, nervousness, difficulty sleeping), hematological (low platelet and hemoglobin values), cytogenetic (chromosomal and lymphatic abnormalities), and carcinogenic effects. Styrene is classified as a possible human carcinogen by the EPA and by the International Agency for Research on Cancer (IARC).[1]; Not as widely recycled as 1 or 2

Commonly Recycled Into: Egg Cartons, Vents, Foam packing, Insulation

7. Other
Any plastic that doesn’t fall under a 1 through 6 ends up with a 7. Bio plastics are also given the label 7. Other items include:

• Microwave Ovens
• Eating Utensils
• Baby Bottles
• 3 and 5 Gallon reusable bottles
• CD and DVD cases
• Electrical Wring

CONS: Made  with biphenyl-A (commonly known as BPA) that can leach into your food – a chemical that simulates the action of estrogen; rare recycling availability.

Commonly Recycled Into: Plastic Lumber and Custom Made Items

Although all plastics should be avoided whenever possible, we can conclude that there are some plastics safer to use than others – 2, 4, and 5 – as they have not been known to leach chemicals after production.[iii][iv][v].