Three studies commissioned by the company Novamont confirm the biodegradability of Mater-Bi bioplastics and their non-toxicity to the marine ecosystem.
Is biodegradable and compostable plastic a genuinely ecological alternative to petroleum-based plastic? And is it capable of respecting a delicate ecosystem such as the marine one? To answer these questions, the Italian company Novamont, a long-standing leader in the bioplastics sector, carried out a series of scientific studies, partly in its own laboratories and partly commissioned to research institutions. The results were presented on 1 July in Rome. And they appear decidedly reassuring.
One caveat is essential: "Science – the Novara-based company itself confirms in a press release – tells us that any substance, material or product released into nature creates a potential ecological risk. Even pouring olive oil from a tin of tuna into the sea is a potential harm to the marine ecosystem." That is why "the end-of-life of compostable products must continue to be what they were designed for: industrial composting through separate waste collection and the recovery of kitchen and garden waste."
That said, packaging is unfortunately often not recovered but abandoned in nature. And what happens in such cases when the bioplastic in question is produced by Novamont — that is, Mater-Bi? The studies focused on three aspects: intrinsic marine biodegradability (assessed in Novamont's laboratories), disintegration in the marine environment (verified by the German marine biology research and documentation institute Hydra Marine Sciences) and ecotoxicity released into sediments (analysis entrusted to the University of Siena).
The studies were also conducted in accordance with international standards, which involve exposing plastic samples to microorganisms present in marine sediments and measuring the conversion of the plastic into CO2.
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Regarding biodegradability, "the tests carried out by researchers in Novamont's laboratories – the company explains – showed that Mater-Bi reaches high levels of biodegradation, essentially equal to those of paper, used as the reference material, within a test period of less than one year." Furthermore, "it was demonstrated that the rate of biodegradation increases as the size of the particles being tested decreases. This means that Mater-Bi does not release persistent microplastics, as they biodegrade completely within 20–30 days."
The assessment of disintegration in the marine environment was conducted by Christian Lott, a researcher at the German marine biology research and documentation institute Hydra Marine Sciences, at the institute's base on the island of Elba. "The test involved compostable bags for fruit and vegetables. In practice, sandy sediments taken from different coastal areas of the island were placed in aquarium tanks with seawater, so as to simulate the seabed where waste naturally tends to accumulate. The bags were placed in the tanks and removed at different time intervals to check for disintegration."
The findings of the study indicate that "the time required for the complete disappearance of Mater-Bi fruit/vegetable bags ranges from less than four months to just over one year, depending on the nature of the seabeds considered and their physico-chemical and biological characteristics."
The ecotoxicity of Mater-Bi was then assessed by Maria Cristina Fossi and Silvia Casini, from the Department of Physical Sciences of the Earth and Environment at the University of Siena. "Tests were carried out on three species of organisms exposed to extracts ("elutriates") of marine sediments inoculated with Mater-Bi or with cellulose. The sediments were incubated at 28°C and tested after 6 months, when clear signs of degradation of the Mater-Bi were visible, and after 12 months, when the inoculated samples had completely disappeared."
The organisms selected were unicellular algae, the sea urchin and the sea bass. "The first two – Novamont continues – were used to investigate any effects of growth inhibition and embryotoxicity, while juvenile specimens of sea bass were tested to assess possible sublethal effects. The elutriates of sediments inoculated with Mater-Bi for 6 and 12 months showed an absence of toxic effects in the model organisms exposed in this study. The degradation process of Mater-Bi did not generate or transfer toxic substances into the elutriates capable of causing alterations in the growth of unicellular algae, embryotoxicity in the sea urchin, or oxidative stress or genotoxicity in the sea bass."
"All products must be collected and recycled – commented the research coordinator, Francesco Degli Innocenti – including those that are biodegradable in Mater-Bi, which must be recovered in the form of compost together with kitchen waste. Nothing should be irresponsibly abandoned either on land or at sea, because this creates a potential ecological risk in any case. The intrinsic biodegradability of Mater-Bi products represents a risk mitigation factor that must not become a commercial message but rather an additional element in assessing the environmental profile of biodegradable products."
Novamont CEO Catia Bastioli added that "in less than a century we have gone from an empty Planet to a full Planet in terms of population, concentrations of greenhouse gases in the atmosphere, and quantities of products placed on the market. If we want to address in a serious and concrete way the complex environmental and social challenges ahead of us, we must think in terms of value rather than volumes, within a logic of circular economy. The regeneration of these precious resources requires minimising the use of products and rethinking them across the entire life cycle."
