Above Nice, is this plastic recycling facility, denounced by a petition, really polluting? Experts decipher...

"A Toxic Industry" These are the words used by residents of Villars-sur-Var to protest the planned arrival, on private land, of a workshop for transforming plastic into furniture., located below the village, in the Plan de Lunel district, in the heart of the AOP vineyard. ", citizens launched a petition, which has already gathered 1,085 signatures.

Objective: to obtain "the immediate abandonment of the project", judging, firstly, the process "emitting volatile organic compounds , fine particles, microplastics, carcinogenic endocrine disruptors likely to be deposited in the air, soil, organic crops or on the river bank". Opposite, Valérie Klein, founder of the company, asserts a "responsible" activity and a "controlled, clean, risk-free" process.

Concretely, it will involve shredding up to 100 tonnes per year of PP and PE plastic (1) – from local industry – which does not require cleaning, grinding them into dry chips, then shaping them into plates in a heated press (up to 180°), cooling them and shaping them into furniture, by adding wood.

A method used by Plastic Odyssey

Prompting a backlash in Villars, the process is used by Plastic Odyssey, an international collective committed to reducing ocean pollution . On its laboratory boat and in a recycling plant based in Dakar, the organization uses more or less the same machines as Zyrclo, whose technical data sheets it shares in open source on its website.

"Shredding allows for an initial volume reduction, while grinding produces chips of the same size and shape, which will have the same heating time. At this stage, a soundproofing system [put forward by the company Zyrclo, Editor's note] is essential because the risk is noise," explains Tom Bébien, technical director at Plastic Odyssey.

In France, he estimates that "less than fifteen" companies use this so-called mechanical recycling process (as opposed to chemical, because no product is involved). Like Carbon Blue, in the Bouches -du-Rhône; or the company Le Pavé, based in Aubervilliers, which notably distinguished itself by producing the seats for the Paris 2024 Olympic Games.

"The process used will have no immediate impact on the environment and health."

Then comes the most controversial part: melting the plastic to shape it. "It involves a cylinder that closes two heating plates. Inside, we place a mold into which we place the shavings. There is then a gradual process between heating and closing the plates to gently melt the shavings and stick them together. Then we let them cool. At this temperature, they do not release smoke or harmful components," explains the specialist. The only crucial point: make sure to only use "clean" plastics, not contaminated by oil or other chemical components that could degrade upon contact with heat.

This observation is shared by Nathalie Gontard, research director at the French National Institute for Agricultural, Food and Environmental Research (INRAE) . For 30 years, this packaging science researcher has been studying plastic from every angle, a work that has made her an international authority on the subject. "The process used will not have an immediate impact on its environment or on health, the heating temperature is not very high," she confirms.

Recycling or downcycling?

However, the scientist has reservations about the substance. "This is not recycling , which consists of generating identical plastic. The only recycling is that , a material with which we are able to remake bottles," she qualifies. For Nathalie Gontard, it is this notion of downcycling that raises questions. "Transforming plastic into furniture means seeking new outlets for the material. It amounts to replacing wood, for example, with plastic, maintaining a dependence on this waste. Moreover, these objects, however beautiful they may be, will continue, like all plastics, to emit micro and nanoparticles throughout their life. The urgent thing is to reduce plastic at the source. Building economic outlets is a vicious circle," she judges.

(1) Polypropylene and polyethylene.

(2) Polyethylene terephthalate.