About 49% of the world’s clothing is made of polyester, and forecasts show this to nearly double by 2030. The Athleisure trend has led a growing number of consumers to be interested in more flexible, more resistant garments. But polyester isn’t a sustainable textile option, as it’s made from polyethylene terephthalate (PET), the most common type of plastic in the world. In short, the majority of clothes globally come from crude oil.

Recycled polyester, also known as rPET, is obtained by melting down existing plastic and re-spinning it into new polyester fibre. To give an example, five water bottles yield enough fibre for one t-shirt.

While recycling plastic seems like an obvious win for sustainability, rPET has both advantages and challenges. Here’s a breakdown of the pros and cons.

Recycled polyester: The pros

1. Keeping plastics from going to landfill and the ocean

Recycled polyester gives a second life to a material that’s not biodegradable and would otherwise end up in landfill or the ocean. Eight million metric tonnes of plastics enter the ocean every year, on top of the estimated 150 million metric tonnes that currently circulate in marine environments. If we keep this pace, by 2050, there will be more plastic in the ocean than fish.

Recycled polyester is just as good as virgin polyester but takes fewer resources to make

Recycled polyester is almost the same as virgin polyester in terms of quality, but its production requires 59% less energy compared to virgin polyester. Manufacturers of recycled polyester aim to reduce CO2 emissions by 32% in comparison to regular polyester. In addition, recycled polyester can contribute to reducing the extraction of crude oil and natural gas from the earth to make more plastic. 

Recycled polyester: The cons

1. Recycling plastic has its limitations 

Many garments are not made from polyester alone, but rather a blend of polyester and other materials. But even pure polyester garments can’t be recycled indefinitely.

There are two methods for recycling PET:

• Mechanical recycling breaks down plastic into small chips, which are then melted and reformed into fibres. This process degrades the fibre’s strength over time, often requiring the addition of virgin polyester to maintain quality.
• Chemical recycling restores polyester to its original monomer state, allowing it to be reused like virgin polyester. However, this method is more expensive and less widely used.

1. The process of recycling PET impacts the environment

The polyester chips generated by mechanical recycling can vary in colour. Some turn out crispy white, while others are creamy yellow, making colour consistency difficult to achieve. Some dyers find it hard to get a white, so they’re using chlorine-based bleaches to whiten the base. The inconsistency of dye uptake makes it hard to get good batch-to-batch colour consistency and this can lead to high levels of re-dyeing, which requires high water, energy and chemical use.

1. Recycled polyester releases microplastics

Last but not least, some counterargue the affirmation that recycled polyester keeps plastic from ending up in the oceans. They still do a little, as man-made fabrics can release microscopic plastic fibres — the infamous microplastics. According to a study by a team from Plymouth University in the UK, each cycle of a washing machine could release more than 700,000 plastic fibres into the environment.

To help prevent microplastic pollution when washing items, you can place them in a filter washing bag to prevent shedding during the wash.