What does biodegradable mean?

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Written By Marc Helman

Tackling new challenges with a passion for the environment.

As our planet is heating up, so is the debate over uncapped consumerism. More than ever before we need to find ways to reduce waste and recycle materials. This is where biodegradable products come in.

When a product is biodegradable it means that the material can be broken down by bacteria, fungi or other microorganisms. The biological process of decomposition may take a long time and involve many different types of bacteria and fungi.

Biodegradation occurs in soil, water, air, on land plants and animals, and in living organisms such as humans. It is an important part of natural processes that are essential for maintaining life on Earth.

Is biodegradable good for the environment?

Bioplastic production has been growing rapidly over the past decade, with global sales expected to reach $10 billion by 2020. The market for biopolymers was valued at $2.5 billion in 2014 ; however, this figure does not include other uses such as packaging or medical applications. 

The question of whether to use biodegradable plastics is a hot topic in environmental circles. Bioplastics are made from renewable resources, but they can take decades to break down and may not be completely gone when you throw them away.

Also, biodegradation requires oxygen, water, soil microbes, sunlight, temperature changes, etc., all of which could potentially impact other parts of our environment.

Advantages of bioplastics:

  • They do not contain any toxic chemicals;
  • they are usually cheaper than conventional polymers;
  • the raw materials used are often more readily available than those needed for traditional plastics;
  • biodegradability makes them easier to dispose of;
  • some bioplastics are recyclable.
  • they do not leach into food or drink like conventional plastics
  • they don’t require toxic solvents to remove them from your home or office

Disadvantages of bioplastics:

  • Some bioplastics have lower thermal stability than their non-degradable counterparts;
  • there are few recycling options for bioplastics;
  • their manufacturing process involves high energy consumption;
  • it takes longer time to degrade;
  • many bioplastics cannot withstand extreme temperatures.

Does biodegradable mean compostable?

No! Composting refers to breaking down organic matter using heat and/or microbial action.   In contrast, biodegradation breaks down complex molecules through chemical reactions without requiring external factors such as heat or enzymes. Some people confuse these two terms because both refer to the breakdown of organic compounds.  

However, there are some differences between the two concepts. For example, while composting releases carbon dioxide during its process, biodegrading doesn’t release CO 2.  

In addition, some people think that “compostable” implies that something will eventually turn back into organic matter while others believe that composting only refers to breaking things down into smaller pieces.  

So what exactly does “compostable” mean?

The term compostable has been used to describe a wide variety of products, from plastic bags and straws to paper plates. But the definition varies widely depending on who you ask.

The U.S. Environmental Protection Agency defines it as any material that can be broken down biologically in anaerobic conditions into carbon dioxide, water vapor, nitrogen gas, biomass energy or humic substances.

What materials are biodegradable?

Biodegradable plastics can be made from a variety of natural and synthetic polymers. The most common types include:

* Polylactic acid is derived from corn starch or sugar cane, which makes it an environmentally friendly alternative to petroleum-based plastic products such as milk jugs and water bottles.

PLA has been used in medical devices for years because it’s highly resistant to heat and chemicals. However, its slow rate of degradation limits its usefulness in some areas.

* Cellulose acetate propionate is another type of bioplastic that comes from wood pulp fibers. CAP is more expensive than PLA, but it degrades faster and therefore might have a better potential for certain applications.

* Polyhydroxyalkanoates, also known as bio-polyesters, are produced naturally by bacteria and algae. They’re often referred to as “green” plastics because they degrade into carbon dioxide and water rather than emitting harmful greenhouse gases like fossil fuels do.

PHAs are commonly found in animal intestines and human skin cells. Some researchers believe PHA plastics will eventually replace conventional petrochemical plastics.

Examples of biodegradable consumer products

Some examples of applied biodegradability are:

How many biodegradable plastics are out there?

There are currently about 100 commercially available biodegradable plastics worldwide. Most of these are based on plant cellulosic sources or microbial fermentation.

There are only two major commercial producers of biodegradable plastics today — NatureWorks LLC and BASF Corporation. Both companies produce their own proprietary blends of biodegradable resins.

How do I know if my product contains bioplastic?

If you want to make sure that your product does contain bioplastic then look for the following:

  • The words “biobased” or “bio-derived” on the label.
  • A symbol indicating that the product has been certified according to ASTM D6866 standards.
  • An indication that the product was manufactured under conditions that meet the requirements of ISO 14046/14051.

In addition, there are several companies who certify that certain products were manufactured using 100% biobased content. For example, BIOFLEX® certifies that its products are free of any petroleum-based ingredients.

What should I consider before purchasing biodegradable plastic packaging?

The first thing to do is ask yourself if you really need the product in a package. If it’s something that can be consumed without any kind of container, then there are no real benefits from using a biodegradable alternative.

For example, coffee beans and tea leaves don’t require containers at all – they just have to be kept dry so as not to go mouldy or stale. On the other hand, some foods such as cookies and crackers benefit greatly from having airtight packages because moisture will cause them to spoil faster.

Next, think about whether the product needs to stay fresh longer than normal. Some food items may last up to three days unrefrigerated but would probably perish much sooner if stored in a refrigerator.

Other things might also benefit from keeping their contents cool. For instance, ice cream tends to melt quickly unless it’s frozen solid. And milk spoils more rapidly when exposed to heat.

Finally, make sure you know exactly which type of biodegradable plastic you’re buying. There are different types available depending on the application.

As mentioned above, PLA, PHA and PHB each have advantages and disadvantages for specific applications. You’ll want to look closely at the label to determine which type best suits your particular situation.

Are bioplastics recyclable?

Yes! Biodegradable plastics can actually be recycled just like regular PET containers. In fact, many recycling programs already accept them.

Check with local municipalities to see what kind of facilities exist where you live. If no facility exists near you, contact your state government to find out how to get started collecting this waste stream.

Are bioplastics safe?

Biodegradable plastics are made from renewable resources so they don’t pose a threat to our environment. But we still need to take care when disposing of them.

It’s important not to put biodegradables down the drain since they could clog pipes and septic systems. Instead, use compost bins or recycle at home centers. Also, avoid putting biodegradables in landfills, since they won’t break down properly.

Why biodegradable products shouldn’t go to landfills

Despite biodegradable products being a suitable choice for restaurants, there are also some downsides. As a result of throwing waste into landfills, biodegradable products often end up buried. As there is very little oxygen under the trash, beneficial bacteria are unable to thrive.

Consequently, biodegradable products decompose anaerobically, without oxygen, resulting in methane, an environmentally damaging greenhouse gas. Methane from landfills can be used to create energy in some landfills, but not all do so. 

Is degradable the same as recyclable?

No. Recycling means taking something apart and reusing those parts again. Degrading materials simply go away after being used once. So while both terms mean the material goes back into nature, one term implies an active process while the other doesn’t.