Does Biodegradable Plastic Turn Into Microplastic?

In recent years, a wave of eco-friendly products has entered the market, positioned as solutions to the plastic waste problem, and biodegradable technology is one of the most prominent among them. The value of this technology as a genuine solution to plastic waste is well established. Yet because it's still a relatively new technology in Indonesia, several misconceptions continue to circulate. From claims that it produces microplastics to accusations of greenwashing, Oxium, Indonesia's pioneering biodegradable additive, has faced its share of these misunderstandings.

Does Biodegradable Technology Really Cause Microplastics?

Research into the biodegradation of plastics made with biodegradable technology dates back to 2009, when a study compared biodegradable plastic against conventional polyethylene (PE). The findings were striking: after three months of mineralization in compost, fungal growth was observed on the biodegradable plastic. Further fungal growth appeared after the plastic was exposed to natural environmental conditions, something that did not occur with conventional PE. Bacterial growth was also recorded during the abiotic phase. These results were published in the journal Polymer Degradation and Stability.

In the years that followed — 2011, 2013, 2014, 2015, and 2018 — additional studies and laboratory tests continued to confirm that biodegradable plastic undergoes complete degradation. Crucially, the process doesn't stop at degradation; it continues through to full biodegradation, ultimately breaking down into CO₂, CH₄, H₂O, and biomass.

Below is a summary of key research on biodegradable plastic technology conducted by both Indonesian and international researchers:

• Ojeda et al., 2009 — Aspergillus and Penicillium were detected after three months of mineralization in compost. Fungal growth appeared after one year of natural exposure — again, something not observed in conventional PE. During the abiotic phase, the bacteria Rhodococcus rhodochrous and Nocardia asteroides were identified.
• Center for Biotechnology Assessment (Balai Pengkajian Bioteknologi), 2011 — This study examined the biodegradation of UV-exposed OXIUM film by using it as a nutrient source for microbial growth. The test results showed a marked increase in microbial colony counts on plastic containing OXIUM, while plastic without OXIUM showed low colony growth that tended to decline after 90 days of cultivation. This confirms that OXIUM can serve as a nutrient source for microorganisms and is biodegraded into CO₂, H₂O, and biomass.
• Gomes et al., 2013 — Microorganisms identified after composting in simulated soil conditions included: Geotrichum spp., Mucor spp., Rhizopus spp., Trichoderma spp., Aspergillus niger spp., Zygomycota, Penicillium spp., nematodes, and protozoa.
• Da Luz, 2013 — Following degradation, biodegradable plastic exhibited the formation of hydroxyl (OH) groups, carbon-oxygen bonds, and visible and microscopic changes, including surface wrinkling, holes, cracking, flaking, and color fading, alongside microbial degradation evidenced by the growth of Pleurotus ostreatus.
• Mukamto et al., 2015 — Research conducted at the Benowo landfill in Surabaya successfully identified Mycobacterium growth on biodegradable plastic film at the site.
• ASTM 6954 Test Report, BPPT, 2018

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