Plastic is one of the world's most widely used and important materials. It is also the leading cause of ocean pollution. Plastic is omnipresent. In New Zealand alone, 252,000 tonnes of plastic waste is discarded and sent to the landfills.

When we hear the word plastic, we immediately think about recycling - but not all plastics are created equal and they come in various types. Unfortunately, not all plastics can be recycled, some types are easier to recycle while others are harder, more expensive and some are not even worth recycling.

Have you noticed the "chasing arrows" symbol on most if not all plastic containers? Did you also notice the numbers inside and how they vary from one container to another?

The chasing arrow has been internationally recognised as the symbol for recycling, and the numbers indicated inside refers to the type of plastic in the product.

1 is Polyethylene Terephthalate (PET or PETE or Polyester) 

This is the most common plastic-type and is also known as wrinkle-free fiber. It is found in most consumer products, water, and soda bottles and some packaging.

This type of plastic contains an inorganic compound called antimony trioxide - a carcinogen than can cause cancer in living tissue. PET bottles are designed for single-use as repeated use increases the risk of bacterial growth and proper cleaning requires the use of strong and harmful chemicals.

2 is HDPE (High-Density Polyethylene)

HDPE is the stiff and thick plastic used to make milk jugs, grocery bag, juice containers, shampoo bottles, oil bottles, medicine bottles, and some plastic bags.

It is more stable than PET, most commonly recycled plastic and is considered a safer option for food and drinks use.

3 is PVC (Polyvinyl Chloride)

PVC is commonly found in plumbing pipes, but it is used in all kinds of pipes and tiles. It is a flexible plastic that is used to make cooking oil bottles, pet's toys, teething rings as well as window frames, garden hoses, sheathing material for computer tables.

PVC is labeled as "poison plastic" due to the number of toxins it can leach. Products made using PVC are not recyclable.

4 is LDPE (Low-Density Polyethylene)

LDPE is the thinner, cheaper and more flexible form of polyethylene. It is commonly used for bags (grocery, bread, frozen food, garbage), plastic wraps, beverage cups, squeezable bottles, food containers.

Of all the types it is considered less toxic than others and relatively safer to use. Not commonly recycled at present but this will change as recycling programs continue to evolve and better equip to handle this material.

5 is PP (Polypropylene)

Polypropylene plastic is tough, lightweight, stiffer and more resistant to heat. Widely used for hot food containers, it also used for pails, margarine and yoghurt containers, potato chip bags and packing tape.

It is considered safe for reuse but only about 3% of PP products are currently being recycled in the US.

6 is PS (Polystyrene)

Polystyrene is a lightweight plastic that most often used to make Styrofoam. It is found in cups, take-out containers, and foam packaging.

This type could leach styrene, an organic compound that is a possible human carcinogen, into food products.

Recycling is not widely available for PS products, this plastic-type accounts for about 35% of the US landfill market.

7 is others or everything else (BPA, Polycarbonate, and LEXAN).

Due to its toxicity polycarbonate is the most common plastic in this category but hasn't been used much in recent years . Many countries have banned the use of PC in baby bottles and infant formula packaging. What is used to make water cooler bottles, car parts, sippy cups and baby bottles is this type of plastic.

Bio-based polymer plastics are included in this category. They are marked with initials "PLA" with chasing arrows symbol near the bottom. This symbol means that they are compostable plastics and can be reused.

Lastly, replace these products with eco-friendly alternatives wherever possible. Switch to reusable cups for your next coffee, ditch the sponge and switch to an Eco Cloth, avoid single use utensils and so much more.