Today is World Oceans Day, and a new report by the United Nations Environment Programme (UNEP) suggests that biodegradable plastics may be just as harmful to marine life as conventional plastic.

The report states that biodegradable alternative materials may have similar toxicity to conventional plastics, and can persist in the marine environment for many years.

The report, ‘Chemicals in Plastics: A Technical Report’, summarises a set of scientific studies, and was released at the beginning of May in the lead up to the United Nation’s negotiations on a global plastics treaty. It aims to support the development of a legally binding instrument to end plastic pollution.

According to UNEP, of the 13,000 chemicals that have been associated with plastics, more than 6,000 have insufficient data to determine their human or environmental impacts. Of the 7,000 chemicals that do have sufficient data, almost 50% have one or more hazardous properties of concern.

The impacts of plastics on marine life are well-known. Vast numbers of marine species are killed by plastic ingestion, entanglement and toxic contamination every year. Species at the top of the food chain, such as killer whales and white sharks, are disproportionately affected due to biomagnification. This refers to toxic chemicals consumed through food, increasingly building up in the bodies of animals as you go up the food chain. Endocrine disrupting chemicals in plastics are particularly concerning because they can impact the functioning of wildlife’s reproductive, immune and nervous systems.

Human health can also be impacted by chemicals in plastics. The report highlights that chemicals found in plastics have been associated with cancer, nervous system damage, hormone disruption and fertility issues.

In an attempt to address these issues presented by conventional plastics, bio-based and biodegradable plastic alternatives have been developed. However, these present similar concerns. UNEP states that “while bio-based plastic can help address the fossil resource challenge, it will not solve the pollution problem caused by chemicals in plastic”.

Studies presented in the report have shown that biodegradable plastics may be as toxic as conventional fossil fuel-based plastics and contain similar types and amounts of chemicals of concern. A variety of synthetic fillers and chemical additives are often used to change the properties of plastics and biodegradable plastics, for example to reduce brittleness. Some biodegradable plastics are reported to only break down in industrial or controlled composting conditions, and persist in marine environments for many years with close to no biodegradation.

Biodegradable plastics can be used in food packaging and other food contact materials, providing a route for people to be exposed to harmful chemicals. Marine life may also be exposed should food packaging litter enter water bodies.

A 2020 study by CHEM Trust and eight other non-profit organisations, also raised concern over the use of biodegradable packaging. The study found that moulded fibre products (e.g. bowls, plates, and food boxes), advertised as biodegradable or compostable disposable products, had the highest concentrations of PFAS compared to other disposable food packaging. PFAS are a group of highly persistent chemicals, and the most studied PFAS are associated with severe adverse health effects.

CHEM Trust is calling on EU and UK authorities to protect their citizens from harmful chemicals by introducing robust legislation to phase out the most harmful chemicals from consumer products by 2030, including in food contact materials.

To reduce your risk of exposure to harmful chemicals in plastics and their alternatives, CHEM Trust advises reducing your overall use of these materials. Here are some helpful tips:

• Buy fresh and loose fruits and vegetables.
• Bulk buy food in refill shops where you can take your own glass or stainless steel containers.
• Store food in glass jars.
• Choose stainless steel bottles.
• Cut down on take aways.
• Use a reusable stainless steel coffee cup.
• Use refillable products where possible. If you do not have access to zero waste stores, there are many online subscription options for refillable items from cleaning products to cosmetics.

Find out more about avoiding harmful chemicals in food packaging on our ‘Food, Food Packaging and Cooking’ webpage.

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