Biodegradable plastic: don’t get carried away too quickly

Bacardi rum bottles, Skittles candy wrappers, designer water bottles: companies are developing biodegradable plastic packaging, touted as more environmentally friendly but which could turn out to be a false good idea.

In the absence of a universal definition of “biodegradable plastic” and the lack of suitable processing centres, observers fear that the arrival on the market of these new materials will contribute to increasing this pollution.

“People tend to believe that they are helping to protect the planet by buying biodegradable plastic products, but that’s not the case at all”, warns Gaëlle Haut, European coordinator of the Surfrider Foundation, an association environmental.

On the one hand, conventional plastics, produced by the petrochemical industry from fossil sources, can persist in nature for hundreds of years.

Conversely, biodegradable plastics, made from specific polymers derived from vegetable, animal or petroleum sources, can decompose rapidly under the action of micro-organisms. But on condition of eliminating them via suitable industrial or domestic composting, explains Ms. Haut.

Some experts fear that these conditions will escape consumers and that they will be led to dispose of these plastics directly in nature.

“People could say to themselves: + I forgot my biodegradable plastic bag in the forest after a picnic, but it does not matter because it will be biodegraded in nature +”, worries Moira Tourneur, responsible for the advocacy for Zero Waste France.

However, biodegradable plastics that end up in natural environments break down into microparticles, at different time horizons depending on the ecosystem.

These “microplastics” infiltrate soils, rivers and oceans, posing a health risk to animals that ingest them. They can even make their way into the human body through our diet.

To avoid the harmful decomposition of biodegradable plastic in nature or in unsuitable landfills, observers recommend the development of new composting and collection centers.

Many experts are also in favor of proposals to regulate the use of the terms “bio-based”, “biodegradable”, “compostable” or “sustainable” used on plastic packaging.

-‘A lot of confusion’-

Consumers sometimes find it difficult to navigate the terminology.

“There is a lot of confusion in the market,” confirms Philippe Dewolfs, commercial director of TUEV Austria, one of the main companies offering brands a “biodegradability” certification in exchange for remuneration.

Adding to the confusion, bio-based plastics are not necessarily compostable or biodegradable, warns Dewolfs.

To qualify as “bio-based”, the plastic must contain an organic material: corn, potato starch, wood pulp or sugar cane. But sometimes you can find materials derived from fossil fuels that are not necessarily biodegradable.

Conversely, so-called “biodegradable” plastics may contain no organic matter at all, but only petroleum-based polymers that meet certain biodegradation criteria.

These plastics are designed to break down into carbon dioxide (CO2), water and biomass, during a composting process. Or, more rarely, in landfills, but provided that specific parameters of humidity and microorganisms are met there.

For now, spirits brand Bacardi says its biodegradable bottle will hit shelves in 2023. Confectionery giant Mars-Wrigley has announced the imminent launch of biodegradable Skittles candy wrappers in the United States.

A Californian start-up, Cove, has even marketed what it presents as the world’s first biodegradable plastic water bottle.

None of these companies responded to AFP’s interview requests.

In the meantime, governments must educate the public about biodegradable plastics and sanction companies that make misleading claims, recommends Gaëlle Haut of Surfrider Europe: “if companies are left to decide what they do, it’s the jungle”.