Total: PLA decomposes in 2-3 weeks in industrial composting, much faster than the 12-week standard
Recently, TotalEnergies Corbion, a Dutch bioplastics producer, released a review of compostable plastics, focusing on the ecological advantages of compostable plastics. Evidence consistently shows that PLA decomposes in 2-3 weeks in industrial composting, much faster than the 12-week standard of EN13432 certification.
Research and practice in different countries and regions have provided strong evidence for the actual performance of compostable plastics:
Research at Wageningen University in the Netherlands focused on the degradation of PLA products in industrial composting. The results showed that PLA products can decompose quickly, whether it is small items such as tea bags or thicker plant pots. PLA flower pots are completely decomposed in 11 days, and PLA tea bags are decomposed in 22 days. If there is incompletely degraded biowaste after the first composting cycle, recycling can ensure that PLA products are completely degraded, which fully proves that EN13432-certified plastic products are compatible with the Dutch industrial composting system with a shorter composting cycle.
The study, conducted jointly by the Autonomous University of Madrid and the University of Alcalá in Spain, covered five composting facilities for five months. The study found that even though the facilities differed in terms of collection systems and processing technologies, no fragments of compostable bio-based plastics were detected in the final compost, again indicating that conventional plastics are the main source of compost pollution. 94%-98% of microplastics in the compost came from conventional plastics, while compostable plastics (such as PLA) were not detected.
A field study by the Witzenhausen Institute and the University of Bayreuth in Germany analyzed 10 final compost samples from eight different biowaste treatment plants. The data showed that the vast majority of plastic particles in the compost came from conventional non-degradable plastics, while compostable plastic film particles accounted for a very small proportion, indicating that compostable bags that meet the EN13432 standard will not pose a threat to the quality of the compost.
The assessment coordinated by the Italian Composters Association (CIC) was conducted in multiple Italian biowaste treatment facilities, mixing compostable plastic packaging with organic waste in different proportions. The results show that compostable plastics can be effectively biodegraded in industrial facilities, with an average degradation rate of 95%-96%, and the content of traditional plastics in compost samples is below the regulatory limit.
TotalEnergies Corbion also stated that the cautious attitude towards the use of plastics is to build a circular product life cycle, giving priority to reuse and mechanical recycling. But the reality is that about 72% of plastic packaging ends up in landfills or flows into the natural environment. In this context, the use of compostable plastics in appropriate scenarios has become an effective way to solve long-term plastic pollution. It can complement the existing recycling system and achieve a closed material loop through composting.
