Guide to Plastics

Plastic by the numbers

Turn a plastic container on its head and you’ll likely find a recycling symbol with the number 1 to 7 inside. The number represents the type of plastic the item is made of and provides consumers with a simple method of checking if it’s recyclable through the local blue bin program.

Type #1 – PET (or PETE)

Polyethylene Terephthalate

Common uses: Water, juice and pop bottles and food packaging.

Material qualities: A clear, hard plastic, PET is hygienic, strong, lightweight and shatterproof. However, it’s intended to be used only once.

Recyclability in Canada: Most municipal recycling programs in Canada accept PET plastic, which is crushed into flakes that can be used to make new plastic packaging and fleece fabric for clothing.

Environmental risks: Over time, PET can break up into smaller fragments in the environment, potentially leaching chemicals into soil and water, which in turn can be ingested by animals with so-far unknown consequences.

Percentage of global plastic waste: 11%

Type #2 – HDPE

High-Density Polyethylene

Common uses: Milk jugs, yogurt and cottage cheese containers, margarine tubs, shampoo and detergent bottles, plastic “lumber,” corrosion-resistant piping, geomembranes and textiles.

Material qualities: More rigid than #1 plastic, high-density polyethylene is a tougher plastic that’s resistant to chemicals and moisture. It’s permeable to gas and easy to form into any shape.

Recyclability in Canada: Highly recyclable and accepted at most recycling facilities.

Environmental risks: There are no known health risks, so HDPE is considered safe to reuse. However, the negative environmental effects are enormous when not recycled, especially considering the plastic can linger in landfills for hundreds, if not thousands, of years.

Percentage of global plastic waste: 14%

Type #3 – PVC

Polyvinyl Chloride

Common uses: Cling wrap, garden hoses, teething rings, window frames, blister packaging, pipes and siding used in construction, blood-transfusion bags and tubing.

Material qualities: Fire, chemical and water resistant, PVC has many uses both in disposable products and in items intended for multiple or long-term use.

Recyclability in Canada: Most recycling programs do not accept PVC, so it most often ends up being sent to landfills.
Environmental risks: Because PVC is rarely recycled, it requires virgin materials—that is, petroleum and natural-gas liquids—to manufacture, carrying with it a considerable carbon footprint from extracting the fossil fuels used to make it to the greenhouse gases emitted during its production. Moreover, PVC contains phthalate, a suspected carcinogen.

Type #4 – LDPE

Low-Density Polyethylene

Common uses: Single-use bags, packaging for consumer products, automotive parts and fabrics.

Material qualities: Soft, tensile and pliable, it’s the resin of choice for shopping bags, but can also be moulded into chemical- and water-resistant hard plastics with a multitude of applications.

Recyclability in Canada: Although LDPE can be recycled, it’s rarely accepted in recycling programs in Canada.

Environmental risks: Because shopping bags often aren’t recycled, and in most cases intended to be used only once, they end up littering nature and the oceans, causing harm and even death to wildlife that ingest them or get tangled in them.

Percentage of global plastic waste: 20%

Type #5 – PP


Common uses: Plastic bottle caps, disposable diapers, textiles, medicine bottles, straws, luggage and toys.

Material qualities: Flexible, tough and semi-transparent, polypropylene is heat and solvent resistant, and can be deployed as a moisture barrier.

Recyclability in Canada: Polypropylene is accepted at most Canadian recycling facilities but many small items, such as straws, cannot be recycled.

Environmental risks: While the plastic itself is considered safe for humans, its manufacturing requires the use of toxic industrial chemicals, including benzene and vinyl acetate. In addition, when discarded in nature or landfills, items like straws and stir sticks can cause harm and even death to marine and animal populations that ingest them.

Percentage of global plastic waste: 19%

Type #6 – PS

Polystyrene and Styrofoam

Common uses: Take-out food containers, meat packing trays, disposable plates and coffee cups, cushioning for packaged electronics and other fragile items, insulation and signage.

Material qualities: Inexpensive, rigid and easy to mould, the high-tensile strength plastic is impact resistant while the rigid foam plastic is lightweight.

Recyclability in Canada: Polystyrene — including the expanded polystyrene foam known as Styrofoam — is generally not accepted by recycling facilities. The low-density foam variety is of such low quality that it simply can’t be reused and turned into other products.

Environmental risks: Polystyrene contains styrene, a known carcinogen that could leach into soil and water. Styrofoam can’t be recycled and ends up in landfills.

Percentage of global plastic waste: 6%

Type #7


A catch-all for miscellaneous plastics made from resins other than numbers 1 to 6, #7 plastic usually refers to polycarbonate, used for items such as large water-cooler bottles, car parts and reusable personal water bottles. This number also includes bioplastics and biodegradable, compostable polymers, indicated with the acronym PLA (polylactic acid), as well as acrylic, fiberglass and nylon.

The packaging used for produce and other foods is often made of a #7 plastic that contains BPA or Bisphenol-A, a known hormone disruptor that has been banned from use in the manufacture of sippy cups and baby bottles and voluntarily shunned by some brands that make water bottles (look for “BPA Free” by the recycling logo).

Environmental risks: As with other plastics, this group of resins may never break down in nature, permanently clogging landfill sites and littering forests, rivers and oceans.

Percentage of global plastic waste: 24%