Biodegradable plastics: blessing or a curse?

biodegradable plastic coffee cup

Biodegradable plastics are becoming more mainstream, but not all of those products claiming to be biodegradable are able to break down. The general perception is that these products will decompose and disappear if left in the environment. However, this is not entirely true.

Many of these plastic products that are labelled ‘biodegradable’ do not actually decompose fully. Recent studies by the University of Plymouth have shown that biodegradable plastic bags still remain intact after three years of being exposed to the elements, floating at sea or buried in the soil. These bags were still able to hold more than two kilograms of shopping at the end of the study.

Plastics are made from long chains of molecules, called polymers. These chains give plastics their well-known properties; strong, flexible, unreactive and durable. Biodegradable plastics are made from natural materials that form these chains – the polymers are supposed to break down naturally. However, there is no standardised timescale that has been specified in which degradation should occur.

Plastics that are labelled as ‘compostable’ have to adhere to stricter standards. These products are required to decompose under industrial composting conditions within three months. Biodegradable plastics, on the other hand, have no set time frame for their decomposition. This can mislead the public into believing that biodegradable plastics are alright to leave in the environment, either through littering or illegal dumping.

Plastics SA supports more sustainable products

Plastics SA welcomes and supports any innovative plastic products that promote sustainability and environmental preservation. We are working alongside plastics manufacturers, the South African government and other industry stakeholders to find a long-term solution to plastic waste in the environment.

We recommend that all plastics need to undergo an environmental impact assessment and cost evaluation. Any environmental claims need to be backed by science and empirical evidence before being marketed to the general public. These biodegradability and compostability claims need to comply with global standards, such as ISO 14021 for environmental labels and declarations.

Biodegradable plastics are not a solution to litter

South Africans should not assume that bio-based plastics have a lower environmental impact than regular plastics. While they may be made from plant-based sources, studies have shown that people are more likely to litter when they believe that their waste will decompose in the environment.

The fact remains that biodegradable and compostable plastics should still be disposed of properly. Recycling is an integral part of South Africa’s economy – recycling facilities process over 350 000 tonnes of plastics every year. Recycling still remains the most viable solution to plastic waste in today’s economy.

Bio-based plastics are not always biodegradable and biodegradable plastics are not always bio-based. Fossil fuel-based plastics can have an element of biodegradability. This is an important distinction as it will help to avoid confusion when addressing the societal and environmental concerns of bioplastics. This distinction will also remind South Africans that their plastics should always be recycled.

Consumers should avoid littering at all costs

While some biodegradable plastic products may decompose when left in the environment, sadly this is not the case for all products with the label. We urge South Africans to think carefully about their waste disposal practices, especially when it comes to compostable and biodegradable plastics. Littering and illegal dumping should be avoided at all costs, regardless of whether a product claims to be decomposable.

Plastics SA would like to encourage consumers to avoid irresponsible waste disposal practices and embrace our local recycling industry. While we work towards creating more sustainable plastic products, consumers can continue to recycle their plastic waste and work towards the country’s zero-plastic-to-landfill goals.

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Plastics SA represents all sectors of the South African plastics industry. ​Together with our associations, we play an active role in the growth and development of the industry and strive to address plastics related issues, influence role-players and make plastics the material of choice.

​Plastics SA has been mandated to ensure a vibrant and sustainable plastics industry in South Africa. The plastics sector is uniquely placed to meet the needs of a sustainable society and to deliver solutions to many challenges such as recycling, climate change, water scarcity, resource usage and energy recovery.

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Plastics SA Editor