They buried four bags that were shown to have biodegradable properties and a traditional plastic bag, in the sea, underground, or left in the open air. After three years, some were almost intact, often strong enough to carry groceries.
In theory, everything is degradable. A lighter breaks down in 100 years, a disposable diaper in 500 years, just like a good old plastic bag. It's just a matter of time.
But biodegradable plastic is a special type of plastic, created to degrade more quickly. For it to work, it requires special conditions related to oxygen, water and bacteria.
Often, in a landfill, where the biodegradable bags end, these conditions are not met. These bags will degrade yes, but it will take a very long time.
Biodegradable, but not recyclable
Moreover, the biodegradable, it does not recycle, as we explain Nicolas Garnier, delegate general of the association of communities Primer: "What people have not understood is that biodegradable absolutely does not want In other words, a biodegradable plastic bag can not be recycled, it will have to be disposed of either in an incineration plant or in a storage center. From an environmental point of view, this notion of biodegradability is very debatable ".
Moreover, there is no universally accepted standard for biodegradable.
The only reliable standard is the compostable plastic bag, these bags of potato starch, seaweed, corn starch ... They are recognized with OK compost logos, which theoretically means a 90% degraded bag in less than six months - always in precise conditions: humidity, 60 to 90 ° C in temperature.
But it only works if someone picks up your carrot peels, egg shells or compost bag. In Europe, very few countries have bio-waste collection. One country is ahead: Italy, where one inhabitant in two sees its food waste collected. In Milan, in less than two years, the second largest city in Italy has become the largest in Europe to set up the system. Today, more than 85% of food waste is collected.
But is the solution to the drama of plastic really a new type of plastic, even compostable? Our guest Laura Châtel from Zero Waste France answers our questions.