Understanding Plastic: The Basics
Updated: Mar 1
Plastic is a material that is hard to avoid in our current society. The phone or laptop you are using to read this? Yes - there's plastic in it. Your morning teabag or coffee? That probably took plastic to make, store, or ship. A bike, car, or bus used to get to work? They are plastic machines! We are surrounded by plastic in places we may not even realize - so what's the deal?
Part 1 of 4: THE BASICS.
To start, what even is plastic? In a more technical sense, plastic is termed as a polymer, which is defined as “having many parts”. Essentially this means that plastics and polymers are made of thousands of small molecules and can come in various types.
Types of plastic are categorized by a resin code (♺), which can usually be found on the bottom of the item.
These resin codes are used to help categorize plastics as each type has different chemical and physical properties, which prove best for varying applications. Plastics with better flexibility, for example, are best for things like bags or shampoo bottles. Stiff or harder plastics are better for commercial use like vehicles, children's toys, or for situations where the plastic may experience heat. The categories can help manufacturers, producers, and those in industry determine which material they are dealing with and how to dispose of it.
♳ Polyethylene (PETE or PET):
Polyethylene is one of the most commonly used plastics for consumer products, largely for items that are intended to be single-use. This can include soda and water bottles, as well as some packaging.
Tip: Carry around your own water bottle, mason jar, or thermos so you have a reusable option.
♴ High-Density Polyethylene (HDPE):
A harder plastic, HDPE is more resistant to deformation or a change in environment. It is used for applications that require something more integral such as household cleaners and detergent.
Tip: Reuse your cleaner containers and refill them, or make a green DIY version!
♵ Polyvinyl Chloride (PVC):
PVC's flexible nature makes it desirable as it can form to many shapes and designs. It is a soft plastic used in many food-related applications like storage and packaging.
Tip: Try to avoid plastic food packaging. For home and on-the-go, invest in beeswax wraps that can be rinsed and reused.
♶ Low-Density Polyethylene (LDPE): LDPE is another plastic that is soft and flexible, and can be found most commonly as plastic bags like those for groceries or bread.
Tip: Bring your own tote or cloth bags when shopping. Leave a few in your car or purse/bag so you always have them!
♷ Polypropylene (PP):
Polypropylene is also amongst the most common in consumer products and recycling facilities. You will see its No. 5 resin code on items like yogurt containers, straws and hygiene products such as shampoo or diapers.
Tip: Make the switch to plastic-free bath products like shampoo bars.
♸ Polystyrene (PS):
Better known as styrofoam, PS is used for to-go containers or when contents need to remain heated. It can be melted and repurposed into new material; however, not all facilities have the proper technology to process it. Be sure to check with your local recycling service if they accept styrofoam, as most programs ask that you take it to a recycling depot.
Tip: Avoid styrofoam when you can, but if you must purchase it, be sure to collect it and return it to a depot for proper disposal.
The final resin code, No. 7, denotes plastics that do not fit into any of the above categories. Usually it means that it is a combination of plastics or mixed materials, and sometimes they are depicted with a blank resin code. They are beneficial when wanting to combine attributes of multiple materials or plastics together, but they are often un-recyclable as it is difficult to separate the original materials used during processing.
Tip: Try to steer clear of mixed plastics as they are landfill items. Repurpose items you already own, purchase second-hand, or source items locally to reduce your plastic impact.
Understanding plastic can be complicated, GO strives to breakdown this important topic in an approachable way; however, if you have questions, reach out to us as we are here to help! Stay tuned for Part 2 of our Understanding Plastic series, where we will dive into a side often not explored by the media: some of the benefits that plastic provides.
Information for this blog was sourced from the lecture notes and readings of Dr. Mohammad Arjmand, a Polymer Engineer and Associate Professor at the University of British Columbia, Okanagan.