Plastic Recycling Codes Explained, Types of Plastic and the Applications of Recycled Plastics

Topics Covered

Background
Plastic Recycling Codes
Number 1 Code - Polyethylene Terephthalate, PETE
Number 2 Code - High Density Polyethylene, HDPE
Number 3 Code - Polyvinyl Chloride, PVC
Number 4 Code - Low Density Polyethylene, LDPE
Number 5 Code - Polypropylene, PP
Number 6 Code - Polystyrene, PS
Number 7 Code - Other

Background

Various forms of plastic are ubiquitous in our modern lives. Unfortunately discarded plastic is also a major environmental problem with non-biodegradable plastics choking waterways, polluting streets and taking up precious space in landfills. Most plastics can be sucessfully recycled. Plastic recycling is made easier by special codes put into the plastic item at the point of manufacture.

Plastic Recycling Codes

Plastic recycling codes come from the The Society of the Plastics Industry, Inc. (SPI) that introduced its resin identification coding system in 1988 after lobbying by recyclers. The recycling codes are explained below.

Number 1 Code - Polyethylene Terephthalate, PETE

Figure 1. Symbol for PETE plastics

Name of Plastic - Polyethylene Terephthalate, PET or PETE
Description - PET or PETE is a clear, tough plastic commonly used as single use bottled beverage containers. It is easily recycled, inexpensive, lightweight and poses a low risk of leaching breakdown byproducts into the environment. It is in high demand for remanufacturers but recyclign rates are only around 20%. Can also be used as a fibre.
Recycling Method - Collected through most curbside recycling programs
Virgin Plastic Uses - Soft drink, water and plastic beer bottles, pillow, quilt and sleeping bag fillings, food containers.
Recycled Plastic Uses - Polar fleece, packaging film, carpets, tote bags, furniture, building materials like panelling and occasionally new containers.

Number 2 Code - High Density Polyethylene, HDPE

Figure 2. Symbol for HDPE plastics

Name of Plastic - High Density Polyethylene, HDPE
Description - HDPE is a readily recyclable, versatile plastic commonly used for packaging. It is usually white or coloured and poses a low risk of leaching.
Recycling Method - Collected through most curbside recycling programs. Some programs only allow containers with necks.
Virgin Plastic Uses - Some garbage and shopping bags, milk and cream bottles, bleach, detergent and household cleaner bottles, motor oil containers, butter containers, yoghurt tubs, milk crates, rubbish bins, pipes and moulded products.
Recycled Plastic Uses - Oil bottles, recycling containers, drainage pipes, floor tiles, synthetic timber, fencing, laundry detergent bottles.

Number 3 Code - Polyvinyl Chloride, PVC

Figure 3. Symbol for PVC plastics

Name of Plastic - Polyvinyl Chloride, PVC
Description - PVC can be either a hard and rigid plastic or flexible and elastic plastic. It can be clear, white or coloured. PVC is a tough polymer and weathers well so is commonly used for siding, pipes and other building materials. PVC contains chlorine so should never be burnt as bruing will release toxic chemicals. The manufacture of PVC can release dangerous dioxins.
Recycling Method - Rarely recycled. May be accepted by synthetic timber or plastic timber makers.
Virgin Plastic Uses - Cleaning product and detergent bottles, shampoo bottles, food packaging, wire conduit, medical equipment, pipes and fittings, siding and hoses.
Recycled Plastic Uses - Pipe and fittings, decks, panelling, truck mudflaps, drainage mats and flooring, speed bumps, mats and shoes.

Number 4 Code - Low Density Polyethylene, LDPE

Figure 4. Symbol for LDPE plastics

Name of Plastic - Low Density Polyethylene, LDPE
Description - LDPE is a soft, flexible plastic
Recycling Method - LDPE is not often recycled through curbside programs. Many stores have programs that allow for plastic shopping bags to be returned to the store for recycling.
Virgin Plastic Uses - Squeezable bottles, shopping bags, food bags like bread and frozen food bags, dry cleaning bags, clothing, carpet, garbage bags, black plastic sheeting, ice cream container lids
Recycled Plastic Uses - Trash can liners and cans, compost bins, shipping envelopes, paneling, lumber, landscaping ties, floor tile Film for builders, industry, packaging and plant nurseries, bags, agricultural piping

Number 5 Code - Polypropylene, PP

Figure 5. Symbol for PP plastics

Name of Plastic - Polypropylene, PP
Description - Polypropylene is a hard, flexible plastic that has a high melting point and is suited for high temperature applications like holding hot liquids
Recycling Method - Collected through some curbside recycling programs.
Virgin Plastic Uses - Ice cream containers, drinking straws, lunch boxes, potato crisp bags
Recycled Plastic Uses - Brooms, brushes, rakes, compost bins, recycling crates, plant pots, motor vehicle parts

Number 6 Code - Polystyrene, PS

Figure 6. Symbol for PS plastics

Name of Plastic - Polystyrene, PS
Description - Polystyrene may be either a rigid, brittle plastic or made into foam products. Evidence suggests that polystyrene can leach toxins into food.
Recycling Method - Collected through some curbside recycling programs.
Virgin Plastic Uses - Imitation crystal glassware, plastic cutlery, takeaway food containers, hot drink cups, meat trays, egg cartons, CD cases
Recycled Plastic Uses - Insulation, packing materials, rulers, office equipment, clothes pegs, coat hangers, light switches, air conditioning vents

Number 7 Code - Other

Figure 7. Symbol for other plastics

Name of Plastic - All other plastics
Description - Number 7 plastics simply icludes all other plastics. These include compostable and biodegradable plastics like polyactide through to acrylic, nylon and polycarbonate.
Recycling Method - Traditionally not recycled but now being collected through some curbside recycling programs.
Virgin Plastic Uses - Water bottles, CDs and DVDs, bullet-proof materials, sunglasses, telephone, MP3 player and computer cases, signs and displays, clothing
Recycled Plastic Uses - Plastic timber, outdoor furniture, pipes, injection moulded products

Source: AZoM