Traditional plastic is all around us in our everyday lives, from the cutlery you receive at a takeaway to the bag you take your trash out in. Unfortunately, many types of plastic are not recyclable, compostable or biodegradable and it’s important to understand which types you are using and any available alternatives.
There are seven key types of traditional plastic, with the most popular being PET (polyethylene terephthalate) used for many plastic bottles and packaging. Other popular plastics include:
- high-density polyethylene (HDPE) commonly used for harder wearing applications like shampoo bottles
- low-density polyethylene (LDPE) commonly used for softer applications like grocery bags and cling wrap
- polyvinyl chloride (PVC) commonly used building construction applications like pipes
- Polypropylene (PP) commonly used for bottles, toys and car parts
- Polystyrene (PS) used for packing
- and other resins.
Some of these plastics are recyclable and some are not.
What Are The Classifications For Traditional Plastic And What Do They Mean?
When it comes to plastic, there are many types of traditional plastic out in the world, including many disposable products. From packaging and food service to trash bags and shopping bags, plastic is everywhere. Many Governments around the world are starting to take action against the use of disposable plastics, with the environment front of mind.
Plastic is actually incredibly complex, with many different types that may or may not be recyclable and may or may not release toxic chemicals when exposed to extreme temperatures or landfill. This article will explore the different types of plastic and how they can be disposed of.
We’re surrounded by plastic in our everyday lives and it’s worthwhile to understand the environmental footprint you are contributing to by using each different type. You can also learn more about alternatives you can choose instead of toxic plastic types.
Plastic Classification Numbers
Plastics are classified in numbers from 1-7 which also helps identify their level of recyclability.
- Other resins.
Many products will have a number on the back or base of the product which indicates the type of plastic used to make the product. These will assist in understanding which products to avoid and which can be recycled and how. Many of your local recycling plants will have a list of product numbers that can be recycled.
The Most Common Plastic: PET
The most common and widely produced plastic in the world is PET (Polyethylene Terephthalate) which is mostly used for bottling and packaging and is recyclable. However, it can still leach a toxic metal used during its manufacturing process.
PET is commonly used due to its ability to withstand heat, its strength, resistance to moisture and alcohols and its flexibility. This type of plastic is also lightweight, making it easy to transport and is essentially shatter-resistant. PET is also approved as safe for food and beverages by many health agencies.
Its most common use is for disposable water bottles, soft drink bottles and is also being utilised in the textile industry through polyester fabrics. PET is recycled by being washed and remelted into new products or breaking it down into raw materials for purification – thermal recycling. Even clothing can be made from recycled PET!
The High Polyethylene
HDPE (high-density polyethylene) is also very common but comes in high- and low-density forms. They are used for robust packaging such as milk bottles or those of cleaning supplies and shampoo. It’s also used for grocery bags but releases estrogenic chemicals.
HDPE is flexible upon heating and is strong once cooled, making it useful for sheeting, engineering applications and product packaging. This type of plastic is resistant to chemical and impact, has a long life-span, is strong and durable yet lightweight and is easily recyclable similar to PET.
HDPE is also used for items such as insulation, fuel tanks, hard hats and water bottles. It can be recycled through being melted down and made into new HDPE products. HDPE is considered a ‘low-hazard plastic’ with a low risk of leaching.
Low Density Polyethylene
LDPE is mostly used for products such as film applications or coatings due to its flexibility, transparency and strength. It works well for food packaging as its mostly resistant to acids and vegetable oils. Some squeezable bottles and toys are also made from LDPE due to its flexibility.
Similar to HDPE, LDPE can be recycled through being melted down and used for new products. This plastic can also leach toxic chemicals if left unrecycled.
Another traditional plastic is PVC (polyvinyl chloride) found in packaging for shrink wrap, blister packs, deli wrap and toys. These plastics contain toxic chemicals that can impact wildlife.
PVC is classed as economical and versatile, being used in building and construction for its low cost, strength and flame resistance. This type of plastic is extremely versatile which is why it’s used for anything from siding and windows to wiring and cables. Not to mention packaging and healthcare products.
PVC is derived from salt and ethylene from natural gas. This means that production of these products may consume less energy and generate fewer emissions. Unfortunately, PVC is also one of the most poisonous plastics and very damaging to the environment as well as people should toxic additives leach.
It is also largely NOT recyclable and contributes to landfill. Some products such as piping can be reused and recycled.
PP (polypropylene) is another thermoplastic used in a variety of products from packaging and plastic parts to textiles and special devices. It is also used for yoghurt containers, medications, takeout meals and have a high heat tolerance. Its slippery surface makes it a possible substitute in low friction applications such as gears in furniture. PP is also very strong and flexible.
PP is recyclable and can be turned into fibres for materials such as clothing. Unfortunately, a small percentage is recycled around the world, contributing to landfill. Due to its high heat tolerance, PP doesn’t seem to leach many of the chemicals other plastics do.
Polystyrene And Food Packaging
Another popular and well-known plastic is polystyrene (PS) which is widely used for food service products such as cups, plates and containers. It is a versatile plastic and often used for food packaging and laboratory ware as well as inside many decorative items as a filler. It is not only lightweight but also shock absorbing. Polystyrene has also been used for many years in post packaging and as storage for fragile items.
It can be toxic when styrene is leached, has a relatively low melting point and it isn’t recyclable.
Resins Used As Plastics
Another type of plastic is resin, which comes in many different types with different additives. Basically, resin is classed as anything not identified above (in classifications 1-6) that may be layered or mixed with other types of plastics – including bioplastics.
In this category, polycarbonate (PC) is the most common plastic. In recent years, this has dropped in its usage due to its association with BPA (bisphenol A). PC is typically used for water bottles, metal food can liners, baby bottles and sippy cups and other similar packaging or reusable items.
PC is toxic and non-recyclable so should be avoided.
What Are Some Compostable Plastics?
Most importantly, there are compostable plastics, such as our compostable trash bags made from PLA. Known as the ‘next generation of plastics’, compostable plastics provide a great alternative to traditional plastics and are much safer for the environment.
PLA can be made from several different natural sources such as corn starch which we mentioned earlier in this article. The main benefits of PLA is that its made from plants instead of petrochemicals from fossil fuels, it is sustainable and ethical, non-toxic, breaks down in an industrial composting facility, uses less energy in manufacturing and creates fewer greenhouse gas emissions.
We explain more about PLAs in this article.
The Downside Of Compostable Plastics
The perceived downsides to compostable plastics is that many are not suitable for hot foods or liquids and they need to be disposed of in a composter or industrial compostable facility or they will not breakdown properly in landfill.
Many consumers also don’t see the difference between traditional plastic and compostable or confuse biodegradable plastic with compostable. Biodegradable plastics cannot be broken down in a composter or industrial composting facility and must be broken down in the ground including landfill where they may leach toxic chemicals.
Different types of traditional plastic still surrounds us, even with the rising awareness of their negative contribution to the environment and landfill. They are used in everyday products from medication packaging and food packaging to toys, engineering and building products.
There are seven main types of plastics, with PET being the most common. Some of these are recyclable – either easily or with sophisticated processes. However, none are completely safe for the environment as they cannot be broken down in a composter or in landfill. They must be recycled to be reused again.
Compostable plastics provide a great opportunity to be mindful that your products (such as trash bags) will return to the earth and be a part of the environmental life cycle. Compostable plastics also don’t leach toxic chemicals and aren’t toxic to humans or pets.
Being more mindful about your product choices will not only positively impact the environment, but also protect your family in the long run. Making ethical, sustainable and environmentally sound choices is becoming easier as time goes on with the introduction of more compostable and biodegradable products.