Many items, such as “biodegradable” and “compostable” products, offer environmentally sustainable benefits. But what do these words mean exactly, and what is the distinction between them? To fully understand the environmental consequences of packaging material, it is essential to investigate and learn about the terminology used to describe and sell them.
Biodegradable vs. Compostable
The distinction between two terms: biodegradability and compostability, is a primary source of misunderstanding. They are not interchangeable, although these words are sometimes used interchangeably. Confusion about such common bioplastic terminology, mainly where bioplastic products are disposed of, can have dire consequences. To correctly and honestly market their goods, companies need to consider the differences between each category. And to make informed buying decisions and adequately dispose of bioplastic goods at the end of use, customers need to grasp these concepts.
We often see the term’ biodegradable’ on certain things that we buy, such as soap and shampoo. But really, what does it mean? Anything biodegradable can break down into mostly harmless compounds quickly and safely. But what makes a biodegradable substance? Anything that is a product dependent on plants, animals or natural minerals is typically biodegradable.
However, they will break down at different rates depending on the original material from which it was made and how much it was processed. According to the American Society for Testing and Materials (ASTM), biodegradables are anything that undergoes degradation as a result of the action of naturally occurring microorganisms such as bacteria, fungi and algae.
Although biodegradable products are not quickly defined, they are broken in a much shorter time than non-biodegradable products such as plastic, for example. Biodegradable objects, as most people assume, can be much more than plants. They can be papers, boxes, bags, and other items that have all been made with the ability to slowly break down until they can consume them at a microscopic level.
Nearly any object, given ample time, can biodegrade. However, the duration of the biodegradation phase depends on environmental parameters such as humidity and temperature, which is why it is misleading for consumers to say that plastic is ‘biodegradable’ without any further context (i.e. in what timeframe and under what environmental conditions).
Compostable means that in a compost environment, a product can break down into natural elements. Because it is broken down into its natural components, the ecosystem is not affected. Typically, the breakdown process takes about 90 days. The ASTM describes compostables as anything that undergoes biological process degradation during composting to produce CO2, water, inorganic compounds and biomass at a rate consistent with other compostable materials and leaves no noticeable, distinguishable or toxic residue.
Certified compostable goods must, unless otherwise specified, be disposed of in a designated municipal composting facility, not at home. Many certified compostable materials need higher temperatures in industrial environments to biodegrade sufficiently rapidly or, in some instances, at all.
Few areas in the U.S. have industrial composting curbside collection, which is why certified compostable goods are better used in closed systems such as theme parks, stadiums and schools, where compostable and organic waste is closely regulated and managed in an industrial composting facility to ensure proper disposal.
Why knowing the difference between biodegradability and compostability is important?
While biodegradable products apply only to any material that breaks down and decomposes in the environment, compostable products are specifically organic matter that breaks down, with many beneficial uses for the end product, including fertilization and soil health improvement.
Most notably, compostable goods do not leave behind chemical traces because they are already sustainable. Unlike compostable goods, it can take many years for such biodegradable products to break down and, in some cases, also leave hazardous waste behind.
For example, plant-based plastics are sometimes classified as biodegradable. While they are supposed to break down more quickly than standard plastic and be safer for the environment, it could take as long as traditional plastics if the right environmental factors are not present.
Although biodegradation is entirely dependent on the materials being exposed to the right amount of compostable products for moisture and temperature, considering external environmental factors, it can easily break down.
The terms biodegradable and compostable dominate in common when it comes to recycling and can cause confusion.
Transparency will allow customers to make better buying choices and ensure that bioplastics are disposed of through the right channels. In the end, enhanced end-of-life disposal of bioplastics reinforces their plan for environmental value by diverting agricultural waste from landfills, eliminating carbon emissions and ensuring balanced resource use.
The emergence of materials claimed to be biodegradable or compostable by the compost industry has led to the establishment of the European Standard EN 13432, which sets out requirements for what can or can not be defined as compostable and what can be considered biodegradable.
Similar standards are also set out in the US Standard ASTM D6400-99.
Composting facilities do not allow many goods that are branded as “biodegradable” because it takes too long to break down and may not decompose completely, disrupting the composting cycle. However, in nearly all composting systems, materials compliant with either the European or U.S. Requirements can break down effectively.