Compostable plastic labels are all around you these days. Whether it is at a grocery store bag, the cutlery at your favorite restaurant takeaway or the utensils at supermarket, compostable plastic is widely being used.
The business world is finally taking responsibility for sustainable development. The consumers are aware of the toxic effects of using conventional plastics and are shifting their attention towards these greener solutions.
Well, there is a lot more that needs to be understood about compostable plastics, the way to use them, and why they are so important.
What are compostable plastics?
Plastics that can biodegrade/decompose through the process of composting are called compostable plastics. Most compostable plastics are derived from organic raw materials like starch (based out of corn, potato, rice, etc) lactic acid, lipids (vegetable oils), soy protein, etc.
Since the source of compostable plastics itself is renewable, they are not considered harmful/toxic for the environment. Like other organic waste, compostable plastics degenerate into CO2, water and organic mass which is readily accepted by nature.
Additionally, there is a new generation of compostable plastics that have not been derived from renewable materials.
These compostable plastics are derived from petroleum and include a microbial process as a part of their making. They also contain certain additives that help in the quick biodegradation of the material.
The number of raw materials being used to create compostable plastics is growing every day.
Starches like corn starch, potato starch, etc are most commonly used.
The industry for compostable plastics is constantly evolving. New materials and technologies are being tested and experimented. The market has hence witnessed a sudden interest in these eco-friendly products.
Characteristics of compostable plastics
Most resins/raw materials being used to create compostable plastics are very similar in their properties to the conventional plastics. That said, different resins have different properties.
Characteristics of resins vary in terms of tensile strength, flexibility, heat resistance, oxygen barrier, etc.
Compostable plastics, depending on their source material, take different time and conditions to compost. While some are meant to compost in natural conditions, others need commercial composting facilities where specialized conditions like high temperature can be met.
However, international standards call for a 60% biodegradation level to be met within 180 days for a product to be called compostable.
While terms like “degradable”, “biodegradable” and “compostable” are often used synonymously, there is a clear distinction.
A Compostable Plastic is the one that biodegrades (break down into CO2, water, and biomass); disintegrates (gets mixed up within the compost), and does not produce any toxic materials within the compost.
Biodegradable Plastics, on the other hand, decompose through a natural process that happens as a result of microbial action. There is no time limitation on the process.
Degradable Plastics break down under specific environmental conditions causing a change in their chemical properties. The process may or may not be a result of natural activities like microbial action. Additionally, while the product may degrade, the end result could often be certain toxic substances.
Estimated composting time
So, how long do compostable plastics take for a complete breakdown?
Wheat or sugarcane-based plastics like straws, plates, containers, bowls, cups, etc can take around 6 months in a home-based compost system.
Kitchen bags/waste bags can take up to a year to compost.
Other stronger materials like heat resistant utensils. Clear containers, etc need a commercial composting facility to meet the desired temperature conditions.
The overall time taken to biodegrade is dependent on various factors like the raw material, the thickness of the material and other environmental factors.
Needless to say, home composting rates are slower than commercial composting speeds where controlled conditions can be provided. It is for these reasons that composting certain products like kitchenware is not recommended at home.
Some international standards have been established to test the compostability of plastics. These include:
- ASTM- 6400-99 (American Society for Testing and Materials)
- (CEN) EN13432 (European Standardization Committee)
- ISO 14855 (International Standards Organisation)
- DIN V49000 (German Institute of Standardization)
The aforementioned organizations specify the criteria for disintegration, biodegradability, and ecotoxicity. Plastics meeting the desired criteria are labeled as compostable.
So how does one identify compostable plastics? Well, all compostable plastics come with a symbol of the certifying international standard. Look out for the label on your plastics before purchasing.
Is compostable plastic beneficial for the environment?
In short, yes. Compostable plastics can be very beneficial for the environment.
Correct disposal of compostable plastics helps them break down into basic ingredients which can easily be re-integrated with the environment.
However, rolling out compostable plastics without proper information about their disposal requirements may actually do more harm than good. The sustainability factor of using compostable plastics as a substitute for conventional plastics depends on the consumers being informed about its disposal needs.
While your local recyclers may sometimes accept compostable plastic, it may not always be the best option. Similarly, just because the label says “compostable”, you cannot place it in the garbage bin. Landfill conditions have low oxygen and insufficient microorganisms for the biodegradation process to happen.
This means that sending compostable plastic to landfills, or a home compost system may release significant amounts of methane.
The best-suggested end life solution for compostable plastics is hence to send them to a local industrial composting unit. These units create the desired conditions for the plastic to break down into CO2, water, and biomass which can be taken up by the soil.
Compostable Plasticware for the Food Industry
Kitchenware including compostable cutlery, compostable plastic cups, compostable plastic containers, compostable straws, and even compostable bags are the biggest users of these eco-friendly products.
The food and catering industry takes up a big chunk when it comes to the requirement of compostable plastics.
Manufacturers are taking a keen interest in producing compostable kitchenware like cutlery, utensils are food packaging material. Thanks to the users who are becoming environmentally conscious while making their purchases.
Restaurants and food packaging units are now embracing the concept of compostable plastic ware. Eco-friendly options like compostable plastic straws, biodegradable plates, and cutlery, etc are now being preferred to the conventional plastics.
However, conventional plastics have reigned the industry for decades now.
So, what’s the need to make to shift? Why use compostable plastics?
A high percentage of foodservice professionals are perhaps still thinking about making the transition. Here is a list of some quick reasons to go for the change:
- Government policies and laws around the world are getting stringent regarding the use of plastics. With the increasing concerns regarding the bioaccumulation of plastics, most policymakers are eyeing compostable plastics with more interest.
- Consumer education has gone to a whole new level. Discussions on terms like “eco-friendly”, “pollution” and “climate change” are common amongst the masses. This has led to users making careful choices for the products that they purchase. Eco-friendly stuff like bioplastic shopping bags, compostable utensils, biodegradable plastic straws are being preferred by customers these days.
- When it comes to kitchenware, compostable plastics are considered safer to maintain food quality. With properties like heat resistance, less permeability for oxygen, compostable plastics work best in keeping the food safe and fresh for a longer duration.
- Conventional plastics may occasionally leak and release contaminants into the food items. However, since compostable plastics are made of organic sources, the issues regarding toxicity are minimal.
- Compostable kitchenware is as durable and attractive as their conventional counterparts. They come in a wide array of colors, shapes, and sizes and are easily moldable. Various bioplastics offer a glossy finish that’s visually better than traditional plastics.
Overall, the forecast for compostable and bioplastic utensils is great in terms of market growth. The market is expected to grow at CAGR of 5.6%. This means that the value may reach up to US$42 million by the year 2024! (Ref: Global Info Research Study)
The future for compostable plastics is definitely promising. However, this is not the only transition that needs to come up.
While both manufacturers and consumers are showing interest in shifting to this greener environment-friendly solution, the efforts from governments across the world need to show up. The need to have industrial composting facilities, collection systems, etc need to be planned and set up accordingly.