Biodegradable and Compostable Plastics

Bio-based and biodegradable materials are not similar, so it is fundamental to know the difference between both them and other related materials. 

Bio-based materials are fully or partly made from biomass, while biomass is made of biological elements. As they are made from renewable sources, bio-based materials can balance greenhouse gas emissions and reduce environmental degradation caused by the disposal of oil-based polymers. Biodegradable materials can be broken down by bacteria or fungi into water, biomass, and natural gases such as carbon dioxide and methane. The ability to biodegrade depends on temperature, microorganisms, oxygen, and water.

Biodegradable plastics must be separated from conventional plastics for recycling, because they contain chemicals that lower the recycling rate if mixed with conventional plastics (Plastic Recyclers Europe, 2018). Some biodegradable materials are also compostable or can be broken down through industrial composting (Oakes, 2019; Van den Oever et al., 2017). However, such composting is not necessarily applied in home or ocean composting environments or other natural environments (The Norwegian Environment Agency, 2018).

Industrial composting is performed under temperatures of 55°C–60°C, with high humidity, and in the presence of oxygen (Van den Oever et al, 2017). Based on European standard EN 13432, which regulates compostable packaging, industrial compostable packaging must be decomposed after 12 weeks and completely biodegraded after six months. The result of this process is 90% carbon dioxide and 10% water and biomass. Oxo-biodegradable or oxo-degradable plastic is a common material containing an additive which helps break it down. Photodegradable plastic is similar to conventional plastic as it is derived from oil-based polymers – if exposed to sunlight, it will break down into small pieces rather than completely decompose.

Global statistics show 2.05 million tonnes of bio-based and biodegradable plastic and 335 million tonnes of conventional plastic were produced in 2017, accounting for about 0.6% of the plastics market. Some 29.4% of conventional plastic is produced in China, 3.9% in Japan, and 16.8% in the rest of Asia. Thus, in total Asia contributes to 50.1% of global conventional plastic production. Bio-based and biodegradable plastics are more expensive than conventional ones. A price comparison shows that a cup made from polylactic acid (PLA) is 30%–50% more expensive than a cup made from fossil-based plastic (The Norwegian Environment Agency, 2018).

Malaysia’s Roadmap Towards Zero Single-Use Plastics 2018–2030 targets zero single-use plastics by 2030. During phase 1 (2018–2021) the Standard and Industrial Research Institute of Malaysia will revise ECO001, the eco-labelling criteria for degradable and compostable plastic packaging materials, to incorporate only biodegradable and compostable products and exclude photodegradable and oxo-degradable products. During phase 2 (2022–2025), the scope of biodegradable and compostable products will be extended, consisting of food packaging, plastic film, cutlery, food containers, cotton buds, polybags and plant pots, and slow-release fertilisers. During phase 3 (2026–2030), the volume of local biodegradable and compostable products will significantly increase and the scope of biodegradable and compostable products extended, including single-use medical equipment, diapers and women’s sanitary products, and other single-use plastics not included in the circular economy.

In response to the massive discharge of plastic waste into the sea, Indonesia’s Ministry of Industry is committed to promoting sustainable and environmentally friendly industry by encouraging the production of biodegradable plastic. The ministry hopes biodegradable plastic production can be multiplied up to 10 times within two years, and targets not only covering the replacement of shopping bags but also all types of packaging in both modern and traditional markets. Statistics show a 200 tonnes/year current capacity of national biodegradable plastic. Plastic consumption in Indonesia is 5 million tonnes/year, which indicates the need to produce biodegradable plastic to meet demand.

Japan introduced the Biotechnology Strategic Scheme and the Biomass Nippon Strategy in 2002 to encourage the use of biomass, reduce fossil fuel consumption, and lessen global warming through biotechnology. The scheme aimed to replace 20% of conventional plastic with renewable resources by 2020, while the Biomass Nippon Strategy promotes the development of biomass towns and the use of biofuels. Biomass Nippon has successfully driven companies to enhance their research and development of bio-based plastic. The Ministry of Environment allocated JPY5 billion (about US$45 million at the time of writing) in 2019 to develop a biodegradable plastic and subsidy provision for companies producing plastic replacements (Barrett, 2018). About 33%–50% of the price of equipment to produce plastic alternatives can be covered by the ministry.

The government is also planning creation of an international standard for marine biodegradable plastics. Companies are working to develop such plastics, while the Ministry of Economy, Trade, and Industry and other experts are formulating specifications. Japan's development of the standard, as a leader in the research and development of marine biodegradable plastic, is expected to boost industrial competitiveness.

The China government has helped fund bio-plastic industries since 2013 to support local businesses and develop such industries nationwide. Biodegradable plastic consumption increased by 13.2% in 2016 (GCIS, 2017), with many Chinese plastic producers switching their plastic materials to biodegradable ones, such as corn, sugar, and other yields (Swift, 2009).