Frequently asked question about bioplastic raw materials and misunderstood concepts

What is the difference between biodegradable and compostable concepts?

What is biodegradable and how is it done. There are many misunderstandings between biodegradation, degradation and composting concepts. Many people use these terms interchangeably and lay claims about their products without having scientific data and tests. Biodegradation doesn’t carry the same meaning with degradation. Landfilling doesn’t have the same meaning with composting.

Biodegradation: Complete biodegradation occurs when the microorganisms in the environment have consumed plastic as nutrition and turned into water and provided the necessary energy for their lives from this source. Microorganisms remove biodegradable plastics from the environment and don’t leave any particle or remain behind.

Degradation: Sunrays, chemicals or partial biodegradation leave decomposed plastic particles and remains behind in the environment. Decomposed materials mix in water and pull chemicals like PCB and DDT which are toxic to themselves. These toxic chemicals can spread over large areas through water animals.

Compostability: It is similar to biodegradation but it is greener. According to ASTM (American Society for Testing and Materials), in order to call a plastic compostable it is needed that it is converted into carbon dioxide, water and biomass at the same time with paper. In addition, it should appear like compost or fertilizer and support plant life. It shouldn’t produce any toxic material. Biodegradation of compostable plastics is only performed in controlled composting facilities. This means that the compost should be saved approximately 10 days at 140 F. Apart from some exceptional bioplastic polymers, composting cannot be performed in waste-disposal plants, on roadsides or in trash bins.

What is the difference between bio-based and renewable materials?

Both of them are useful and their usage areas are wide. However, they are sometimes used wrongly. The questions that are needed to be asked: does bio-based mean biodegradable or does renewable mean bio-based or biodegradable.

Bio-based: Bio-based product has biologic raw materials and feedstock. For example, corn, soybean, sugar cane and grass. Product can be 100% bio-based or at lower rates.

Renewable (Sustainable): Corn, soybean and sugar cane are also the renewable feedstock because you can plant them again every year and produce. Wood is also a bio-based feedstock but renewability feature occurs in a longer process. Oil and natural gas aren’t renewable resources.

Although a material is bio-based or renewable this doesn’t mean that it is biodegradable or compostable. Similarly, some oil-based materials, like synthetic-based plastic raw materials, are biodegradable and compostable but don’t contain any renewable resource.

The only way to understand whether a product or material is biodegradable and compostable is that it has to be in accordance with scientific standards specified by neutral test societies.

What is oxo-degradable?

Those who want to get profit from biodegradable and renewable resources don’t assert right claims. International biodegradable polymers association (IBAW) in Europe and Products Institute in North America (BPI) have also some concerns about these claims asserted for oxo-degradable formulations.

Only a few of the oxo-degradable products have fulfilled the conditions stated in necessary test standards called ASTM 6400 and EN 12432. Degradation process of an oxo-degradable nylon bag product of a brand has decomposed in high humidity rates as a result of an independent test.

Oxo-degradation process is started by adding heavy metal. Cobalt element levels in products have been arranged in countries like Canada. In oxo-degradable nylon bags this level is above the allowed limit in Canada.

ASTM has tried to set some standards in order that oxo-degradable plastics don’t give any harm to the environment. However, these standards haven’t been set yet and the products are being produced without obeying any standard.

In Turkey, Ministry of environment and urban planning has started a work in order that “biodegradable” nylon bags are used. In this respect, General Director for environmental management has made a statement.

General Director for environmental management Mehmet Baş stated that they will give prominence to those who don’t give harm to the environment and continued: “They are producing such biodegradable bags that chemicals are also used in them. These are dissolved in two month but because of those chemicals they pollute water and soil. We don’t want this, too. We want that it is dissolved in two month with natural ways not with additives. For this reason, we are planning to set some standards on biodegradable bags. We give importance to bio-bags that are completely free from chemicals and in compliance with nature. In fact, we prefer string bag and brown bag”.