Plastic Packaging: Material Choice

Packaging has to fulfil certain functions depending upon the product it is protecting.  Proposals to limit the choice of polymers that brands and manufacturers can use are generally intended to boost recycling. However, these proposals could do more harm than good if the level of protection offered by the packaging is compromised.

Why are so many different types of plastics used?

• Plastic materials available have different combinations of properties, making them suitable for specific applications. Packaging needs to withstand extreme temperatures, e.g. being placed in the oven and/or the freezer. If frozen, it must not become brittle and keep its strength when it is thawed. Packaging also has to be tailored to keep gases, odours and moisture contained within the pack or prevented from entering the pack to varying degrees, depending on the product itself and how long it is being stored for.  It can require a very tight seals to prevent the escape of moisture and gases.

• Packaging has to be either rigid or flexible depending on the application, as well as generally needing good resistance to punctures, scuffs, tears, and UV light.  It sometimes has to be resistant to strong chemicals for prolonged periods, e.g.  bleach bottles, or  needs to provide insulation to keep contents cool for prolonged periods, e.g. the boxes used to store fresh fish.

• Packaging may need to be transparent so that the contents of a pack can be inspected and often has to be appealing to the consumer in terms of colour, shape and ergonomics, while also offering extra functionality such as being 'easy tear', squeezable or snapping without breaking, e.g. in the case of yoghurt pots.

In conclusion…

Calls for the use of fewer polymers could increase environmental damage, as using the right material ensures that food waste is minimised and products are suitably protected. The packaged products often require more of the planet’s resources to grow or manufacture and deliver than the packaging protecting them. Different polymers are selected because of their unique properties.

Limiting the choice of polymers could limit the efficiency and functionality of plastic packaging, increasing waste and using more resources. Food waste is especially damaging to the environment due to the significant amount of Carbon dioxide equivalent (CO2e) generated during food production, transportation, and storage. The plastic packaging protecting the food creates far less CO2 in comparison. 14% of food in the world is lost before it even reaches a retailer [1] and a further 17% is wasted in retail and by consumers, particularly in households.

Disallowing the use of any polymer for packaging purposes should only be done in exceptional circumstances and if there is a viable alternative that could replace it without any loss of functionality and performance, or reduction in resource efficiency. The range of products that can be recycled is constantly widening. For example, developments mean recyclers will soon be able to recycle laminate materials with advanced recycling technologies. The function of some laminate structures may also be fulfilled by innovative, single-material structures that offer the same functional and resource-saving benefits.

If local authorities develop a consistent approach to the collection of used plastics (‘simpler recycling’) it will increase the amount of plastics that are recycled. It should also stimulate technical developments needed to expand the range of materials that are recyclable at an industrial scale.

Finally, limiting polymer choice could hinder innovation by stopping designers and customers from having access to new combinations of properties in a material.
 

First Published April 2019
 

Reviewed and Updated April 2024

Reviewed February 2025

Sources

1 -  Food and Agriculture Organization of the UN "State of Food and Agriculture (2019)"