Plastics Used in Food Packaging in Australia

This guide explores some of the most common plastics used in food packaging, detailing their unique benefits and key properties, including how they react to heat, with a focus on how to properly recycle them in Australia.

Navigating the world of plastic packaging can be confusing. From the materials used to their recycling codes, there's a lot to learn about what keeps our food fresh and safe.  This guide is about a 1 minute read and will give you a summary of the main plastics used in food packaging, their benefits, softening points (to determine which ones can only be used for cold foods) and recyclability. Scroll to the bottom to see a summary table for quick reference.

Polyethylene Terephthalate (PET)

Benefits: PET is a highly versatile and widely recycled plastic. Known for its exceptional clarity and strength, it provides an excellent barrier against moisture and gases, which helps to preserve the freshness of food and beverages. It is also lightweight and shatter-resistant, making it a cost-effective and safe choice for a variety of products.

Softening Point: PET has a high melting point, but its glass transition temperature, where it begins to soften and lose its rigid shape, is around 70°C. This means it is not suitable for microwaving or hot-fill applications, but it performs well for cold food items and beverages.

Recyclability (Australia): PET is widely recyclable through most council kerbside collections and is identified by the recycling code #1. It is the most commonly recycled plastic in Australia and is processed at facilities like Circular Plastics Australia, which turn old bottles into new food-grade packaging. It's important to place lids on or off the bottles, depending on your local council's advice, to ensure they are sorted correctly.

Polypropylene (PP)

Benefits: PP is a tough and heat-resistant plastic, making it a favorite for microwaveable food containers and items that require hot filling. It is also highly resistant to chemicals, oils, and grease, which makes it ideal for packaging a wide range of foods, from frozen meals to hot soups. PP is lighter than many other plastics, which can help reduce transportation costs.

Softening Point: PP has a high softening and melting point, typically between 160°C and 166°C, allowing it to withstand high temperatures without deforming.

Recyclability (Australia): PP is recyclable and is assigned the recycling code #5. It is widely accepted in Australia's kerbside recycling bins, particularly for rigid items like ice cream, margarine, and yoghurt containers. However, soft plastic PP packaging, such as cling wrap, must be collected separately through specialist programs, if available, and should not be placed in your yellow-lidded bin.

Polylactic Acid (PLA)

Benefits: PLA is a bio-based plastic derived from renewable resources like corn starch. It is a popular, eco-friendly alternative to traditional petroleum-based plastics because it is designed to be composted. PLA is known for its clarity and is often used for clear cups, deli containers, and other cold-food packaging.

Softening Point: PLA has a low glass transition temperature of approximately 60°C, causing it to soften and deform when exposed to heat. This makes it unsuitable for hot food, hot beverages, or microwave use.

Recyclability (Australia): PLA is not recyclable through traditional kerbside recycling and is assigned the recycling code #7. It is crucial to keep PLA separate from conventional plastic recycling streams to avoid contamination. This material is designed to be processed in a commercial composting facility. Look for the "Seedling Logo" on products as a certification that they are compostable under Australian Standard AS 4736.

Crystallized Polylactic Acid (CPLA)

Benefits: CPLA is a crystallized version of PLA that is created through a special process that enhances its heat resistance and durability. This makes it a robust, plant-based alternative suitable for hot food and liquids. It is typically opaque (often white or black) and is commonly used for compostable cutlery, coffee cup lids, and hot soup containers.

Softening Point: The crystallization process increases CPLA's heat resistance significantly, withstanding temperatures up to around 85°C.

Recyclability (Australia): Like PLA, CPLA is not recyclable through traditional methods and is designed for industrial composting. It also falls under the recycling code #7 and must be kept out of plastic recycling bins to prevent contamination. Always check for the "Seedling Logo" to confirm its compostability.

Polystyrene (PS)

Benefits: Polystyrene is a low-cost, lightweight plastic that can be rigid or foamed. It's often used for single-use items due to its excellent clarity and ability to be easily molded into various shapes. General-purpose polystyrene (GPPS) is clear and rigid, while High-impact polystyrene (HIPS) is tougher.

Softening Point: Polystyrene has a softening point of approximately 100°C, which is why it is not typically used for hot-fill or microwave applications.

Recyclability (Australia): Polystyrene is identified by the recycling code #6. In Australia, expanded polystyrene (EPS) foam, such as packaging peanuts and meat trays, is generally not recyclable in kerbside bins. It is considered a problematic plastic and is best disposed of in the general waste bin or at a specialized drop-off location.

Oriented Polystyrene (OPS)

Benefits: OPS is a form of polystyrene that has been stretched to increase its strength and clarity. The "orientation" process gives it superior durability and a brilliant, crystal-clear appearance compared to standard polystyrene. This makes OPS an ideal choice for showcasing products like pastries, baked goods, and deli items in transparent clamshell containers and bakery trays.

Softening Point: Similar to standard polystyrene, OPS has a low softening point, making it suitable for cold and room-temperature food applications but not for use with hot food or reheating.

Recyclability (Australia): As a variant of polystyrene, OPS is also assigned the recycling code #6. Its recyclability is subject to the same challenges as other polystyrene products; it is generally not accepted in Australian kerbside recycling and should be placed in the general waste bin.

Summary

Plastic Type Recycling Code Softening Point Recyclability (Australia)
PET #1 ∼70°C Widely accepted in kerbside bins.
PP #5 160°C−166°C Widely accepted for rigid plastics in kerbside bins.
PLA #7 ∼60°C Not recyclable in kerbside bins. Suitable for general waste. Suitable for commercial composting.
CPLA #7 Up to ∼85°C Not recyclable in kerbside bins. Suitable for general waste. Suitable for commercial composting.
PS #6 ∼100°C Generally not accepted in kerbside bins; place in general waste.
OPS #6 Low softening point Generally not accepted in kerbside bins; place in general waste.