Bioplastic, biodegradability, compostability and new materials

This video is about bio-plastics, as opposed to conventional plastics. You will see why current policies increasingly promote their implementation, but you will also see the limits and difficulties. You will become familiar with terms like Biopolymers Circular Ecnomy, Recyclable, Biodegradable and Compostable. Due to their versatility, plastics are ubiquitous in our daily life, from your toothbrush to kids’ toys …as well as most of the packaging of food and drinks that we commonly buy, and other containers. You surely recognize these typical packages. Plastic production has doubled in 15 years, up to 359 Million tons globally in 2018, and could grow to 1,124 Million tons by 2050. Packaging accounts for 40% of all the plastic demand.

Besides the potential health concerns arisen from direct use, the massive global dependence from plastics has three serious drawbacks. FIRST. Conventional plastics are derived from petroleum or gas, which are non-renewable resources, in the hands and for the profit of a few. Changes in oil prices result in more expensive plastics which, in turn, affect the price of the products that we consume. SECOND. Conventional plastics are not biodegradable, which means .. they do not degrade in nature. This generates hundreds million tons of plastic waste every year. Most plastics can be recycled, that means that they can be re-processed after disposal to produce a new plastic product.

This is very positive, if we could achieve 100% … … however reclycing needs collection and sorting, not easy operations. Collection requires organization and sorting is complex due to the variety of different plastics, In the end, even in virtuous societies only a small quantity is being recycled into really re-usable materials. The majority is thrown in landfills or in the environment, where it can take around 400 years to decompose. Much of the discarded plastic ends up in rivers and from here to the oceans.

Once in the oceans they are transported by currents and accumulate giving raise to what is called “garbage islands”, a mass of waste in the ocean of about 16 millions square Km (to give you an idea, that is much bigger than Europe). THIRD, and this is our key subject, migration of chemicals into our food and drinks. Conventional plastics release chemicals such as plasticizers (see Week 1) …..and some of these have documented endocrine interfering activity (see Week 2). Environmental Protection and Global Health are issues that have generated great discontent, and many feel that we need to change. As opposed to the current LINEAR model in which raw materials are depleted, processed, consumed and thrown away …

…..a circular model aims to close the cycle minimizing both the consumption of limited resources and the generation of waste. In order to progress towards circular economy, in the packaging business much research is being done to develop BioPlastics. As opposed to conventional plastics, bioplastics are either produced from renewable resources, or they are biodegradable, or both. We talk about renewable resources when the source material used for the production can be restored by nature or by human action, and thus is sustainable. The term bioplastic is used for polymers which can degrade in nature by biological mechanisms, turning into water, carbon dioxide or methane, and leaving no wastes.

Most biopolymers produced by natural renewable resources are also biodegradable (THESE with the GREEN SIGN), but some human-made bioplastics turn out to be non-biodegradable (these with the red signs). There are several methods to test the biodegradability or compostability of plastic materials. These two terms refer to the decomposition of matter by biological means. The difference between the two is that Biodegradation is a fully natural process… … while Composting is human-driven, although still largely natural, process Bioplastic packaging must fulfill four criteria in order to be accepted for industrial composting, as indicated in the EN 13432 regulation. FIRST It should disintegrate and in 3 months the residual mass should be less than 10% of the initial.

SECOND 90% biodegradation must be reached within 6 months. THIRD. No negative effects should be observed in the composting process. FOURTH the amount of heavy metals in the final product should be below a maximum tolerated value. The conditions in industrial composting can radically differ from basic home composting, in terms of oxigen input, temperature or soil composition. Finally, a number of certificates assure the suitability of products for industrial or home composting. Other certifications mark the bio-based origin or the biodegradability or materials. Next time you go shopping, look for these specific labels on the biopackaging.