Anything marked with an SPI code of 1 is composed of polyethylene terephthalate which is usually just called PET. Products made from PET are typically water bottles, containers for medications, food jars (like the ones that peanut butter come in), and even combs. Once recycled, it is frequently used to make:

• the filling in warm winter jackets
• carpet
• tote bags
• rope

SPI 2 marked products are made of high-density polyethylene, also called HDPE. Americans will find that their milk containers, shampoo and conditioner bottles, laundry detergent, and other cleaning products are made from this type of plastic. After it’s broken down, SPI 2 is reused to form:

• Plastic boards
• Lumber
• Fencing
• Flower pots
• Plastic crates

Polyvinyl chloride, commonly known as PVC, is SPI 3. Many people are aware the PVC makes pipes used in plumbing, but few are aware that it is also used in flooring, siding, and other goods used in construction. It is rare that SPI 3 is recycled but when it is, it is generally used to make the traffic cones, mats, or coated fabrics.

SPI 4 is made from low-density polyethylene, AKA LDPE. It is a very flexible form of fabric which is why it is perfect for plastic bags, squeezable bottles like the ones ketchup is stored in, and sandwich bags. SPI 4 plastic doesn’t have to be that flexible, however, and when reused, it often makes:

• Garbage cans
• Lumber
• Furniture

Polypropylene is the type of plastic marked with SPI 5. Since PP is able to withstand higher temperatures, it is commonly found in Tupperware containers. It is also used in diapers, syrup bottles, plastic bottle caps (this is why you are often asked to remove the cap when recycling a water bottle), and yogurt containers. Repurposed PP is used in rakes, battery cables, and even ice scrapers.

Many people are surprised when they find out that Styrofoam, which coffee cups, packing foam, and food boxes are made out of is actually a plastic. While not often recycled, it can be turned into insulation, license plate frames, and rulers.

This category actually encompasses a few plastics – the leftovers if you will. Examples include polycarbonate and polylactide, which can often be found in products such as baby bottles, storage containers, CD’s, water jugs, and plastic lumber. Due to the energy needed to break down the plastics in this category, recycling is not often an option.