Thailand's bioplastics industry is expected to explode in the coming years. Behind the green "compostable" and "plastic-free" marketing campaigns associated with these materials, there are a number of issues that need to be addressed.
What do you think of when you hear the word "bioplastics"? Biological? Biodegradable? If you've made the leap from the prefix "bio" to the more environmentally friendly bioplastics, you're not alone. Bioplastics are quickly becoming one of the most popular tickets for companies seeking to escape the plastic pollution crisis.
On paper, bioplastics sound like the ideal solution. They are made from renewable biomass materials, such as plant matter, food and agricultural waste; they behave, feel and act like ordinary plastics; and they are designed to biodegrade or decompose so that hundreds of years will not clog landfills or require expensive recycling.
These bioplastics should allow us to continue to use single-use plastics normally, while reducing our dependence on fossil fuels and relieving pressure on our already overloaded waste management systems. Finally, if these plastics do leak into the natural environment, they will break down anyway, thus protecting the marine animals that have been the victims of our plastic pollution problem so far. Sadly, in most cases, if it sounds too good to be true, there's something wrong with it - and here's why.
What are bioplastics and how are they different from traditional plastics?
Most of the plastics we use in our society today and clog our waterways and beaches are made from crude oil. These plastics can be called "petroleum-derived", where the petroleum is heated, distilled and its molecules are arranged in chains (a process called polymerization) until they form the different types of plastics we use in our daily lives.
Bioplastics are derived from biological sources, such as vegetable fats and oils, corn starch or other biological wastes. They are manufactured by processing and modifying these raw materials into new compounds and polymers, much like the use of petroleum-derived plastics.
The result is a variety of materials that behave, feel and act like "normal" plastics, while negating the carbon footprint and negative connotations associated with plastics produced from crude oil. However, when it comes to the disposal and end of life cycle of these bioplastics, major question marks loom over their environmental credibility.
What constitutes bioplastics remains unclear. The term is widely used for a range of different products that can be bio-based, biodegradable, or both. This could mean that petroleum-derived plastics could be labeled "bioplastics," even if they contain no biological components at all.
Unsurprisingly, this definition makes bioplastics an attractive investment area, offering flexibility and green credentials with minimal investment in supporting infrastructure to facilitate distribution and consumption. So much so that between January 2019 and December 2021, the Thai government is granting tax breaks of up to 125 percent to companies that produce and use bioplastics in an effort to expand the industry.
Do they biodegrade?
"Bioplastics are another way to use renewable resources and create the same problem." - Mike Centers, Titus MRF (Material Recovery Facility) Services, Los Angeles (2018).
Companies investing in bioplastics have been keen to market them as biodegradable or compostable, often using green labels and even calling their products "eco-friendly" or "plastic-free". To find out why the problem is so serious, it is important to distinguish precisely what these terms "biodegradable" and "compostable" mean and how they can be distinguished from simple "degradable" materials.
Degradable means that the product will eventually "break down". Technically, this means that everything is biodegradable, even petroleum-derived plastics. These can "degrade" into tiny plastic particles called microplastics, which cause health problems for animals and humans. Microplastics have been found in our stomachs, lungs, breast milk and even blood .
On the other hand, being biodegradable means that the material can break down naturally with the help of additives in the plastic or organisms such as bacteria and fungi. This could mean that even petroleum-derived plastics (which can be labeled as "biodegradable" if the right additives are added).
"Compostable" goes a step further, meaning that the product will decompose with proper heat, moisture and the help of fungi, bacteria, insects or worms.
What is often overlooked in marketing campaigns and eco-themed advertising around the purpose of bioplastics is the fact that most of these materials can only be biodegraded or composted under precise, carefully managed conditions. These can only be found in industrial composting facilities, which maintain stable temperature and humidity levels to allow bioplastics to decompose.
It is virtually impossible to achieve such conditions in your typical backyard or community-level composting site. However, consumers have been misled to associate the "compostable" label with throwing bioplastic waste into the home compost bin.
To make matters worse, certificates of biodegradability or compostability are often issued to companies based on laboratory test conditions rather than real-world examples. In the laboratory, bioplastics can be tested as fine powders under optimal conditions to speed up the process.
If we can't rely on the "biodegradable" or "compostable" labels, what do we want to do with these bioplastics?
So why not just recycle them?
The fact that these materials feel, behave and look like petroleum-derived plastics means that they can be recycled just like petroleum-derived plastics. However, since they do not come from the same raw material, this is unfortunately not possible.
Blending bioplastics into existing petroleum-derived plastic recycling systems can actually do more harm than good. Even the slightest contamination of bioplastics into a batch of petroleum-derived plastics can render it worthless and result in the entire batch having to be sent to a landfill. This could spell disaster for existing, well-established recycling systems. These facilities may need to invest in sophisticated optical NIR systems to differentiate between polymers used to make different plastics.
This can be costly for developing countries where poor plastic waste management is already significant, even before the added complexity of bioplastics.
Around the world, millions of informal waste pickers are often the primary, if not the only, form of waste management. If these people cannot easily distinguish bioplastics from petroleum-derived plastics that they can sell for recycling, then this poses a real threat to their livelihoods.
Use of food in the manufacture of bioplastics.
Bioplastics are often derived from the edible parts of food crops such as corn, soybeans and potatoes. A recent study found that replacing all plastic packaging with bioplastics would require more than half of the world's corn production. In Thailand, the Thai Board of Investment has identified cassava and sugarcane as the most likely raw materials for future bioplastics production. Of the 40 million tons produced annually, less than 1 percent is currently used to produce bioplastics, and they are said to be ideal raw materials.
The world is also grappling with global hunger and food waste. Globally, 1.3 billion tons of food is wasted each year, accounting for 8-10% of global greenhouse gas emissions. In Thailand, 64% of the waste is food waste and less than 2% is composted in the Bangkok Metropolitan Area. The perverse idea that we should produce plastic bottles and cups from very good food crops that we use once and then throw away and send to the landfill should set off alarm bells in all sectors of society.
What can be done?
We desperately need clear communication and simple, standardized labeling from plastics companies about the true characteristics of the materials they sell to us. Bioplastics must be clearly defined and the terms "degradable", "biodegradable" and "compostable" expanded to distinguish between plastics that can be home composted or need to be sent to industrial facilities. Labels such as the existing recycling triangle implemented for petroleum-derived plastics should also be clearly visible.
The Royal Thai Government should enforce these changes by introducing a bioplastic labeling law and should work with other ASEAN member countries to ensure consistency of regional messages. Without clear labeling, consumers and the informal waste collection sector will be (visually) unable to distinguish between petroleum-derived plastics and bioplastics.
Bioplastic materials that mislead the public and do not meet their qualifications should be banned from sale and use in the country. For example, Thailand has successfully banned oxo-degradable bags. Such a ban should be extended to the import of plastic waste from abroad.
The Thai government could also consider banning the use of edible food crops in the domestic production of this material. This will protect critical food security while also making use of previously underutilized food waste, such as waste vegetable oil or agricultural waste.
