Biodegradable plastic packaging and products: Unveiling the hidden meaning
I buy some biodegradable plastic packaging, usually biodegradable trash bags, and love that warm, fuzzy guilt-free feeling one gets from doing something good. But suddenly I realised, what does this word even mean?
If pressed, you might say it means that the material of your biodegradable plastic packaging and other products has the ability to break down. But the questions most of us forget to ask are:
How long does it take to degrade? What is going into my biodegradable trash bag that I can possibly compost or otherwise avoid? How much energy is used in the making of this bag or product? Does it leave any kind of toxic residue?
The Federal Trade Commission (FTC), a US government agency, defines biodegradable materials as those that, after decomposing through exposure to air, moisture and bacteria, become elements found in nature. However, even the FTC notes that biodegradable products may not break down easily if hidden under a landfill or not exposed to sunlight, air and moisture.
Biodegradable plastic packaging and products: Damage to the environment
A recent article in California Watch on whether biodegradable plastic packaging and products can damage the environment contained some interesting insights. We can safely assume that biodegradable trash breaks down more quickly than ordinary garbage does, but what is little known is that the result is a more rapid release of methane, a greenhouse gas that contributes to global warming.
Meanwhile, many landfills only collect methane after two years has passed (if they do at all), during which time a quickly-degrading plastic has already released its noxious gas. Therefore, a slower rate of decomposition may be better for the environment.
However, the primary researcher of the study contends that the take-home message of the study is not that traditional plastics are better for the environment, but that landfills need to do a better job collecting gas. In fact, a more positive environmental outcome comes from composting food and yard wastes instead.
Non-biodegradable plastic packaging and products
Unfortunately, while the debate on biodegradable plastic and products rages on, the reality is that non-biodegradable products are the norm. Though I rarely go out to eat, I still see takeouts using plastic knives, forks, spoons and plates. I see rubbish dumps overflowing with rubbish, even beautiful landmarks defaced by trash.
These materials take hundreds to millions of years to degrade, and simply pile up. More than just an eyesore, they also threaten our already endangered wildlife, who can mistakenly eat it or be suffocated by it, only to die a slow, agonising death. Plastic is one of the most horrifying legacies of our obsession with convenience.
So what is the solution? First we have to understand what goes into the making of these biodegradable materials.
Biodegradable plastic packaging and products: What are the materials used?
Various materials are used in biodegradable plastics and products. These can include corn starch, sugarcane, paper, fruits, vegetables, leaves, seeds etc .
Bioplastics are made from materials such as cornstarch, sugarcane and tapioca. However, good as they sound, it is important to investigate deeper when major conglomerates not known for their ethics, such as Dow Chemical, invest in bioplastics. So what's the downside?
Biodegradable plastic packaging and products: The hidden cost
Again, this solution comes with its own problems, as these crops are usually grown using large amounts of pesticides and fertilisers.
Researchers in a University of Pittsburg study on the ecological cost of bioplastics found that while production requires less fossil fuel and has a lower impact on global warming, they have higher impacts for eutrophication (when ecosystems such as marine habitats accumulate minerals, leading to algal blooms), eco-toxicity and the production of human carcinogens.
In fact, another study notes that both biodegradable and regular disposable plastic bags require a similar amount of energy, natural resources and costs to produce.
However, the researchers also note that using cellulosic sources of biomass, such as corn stalks, grasses, or woody plant parts (renewable materials, so to speak) reduce impact, use less chemicals (note: chemicals still used) and can produce higher yields.
Compostable plastic products and packaging
Another alternative to biodegradable plastic packaging and products is compostable plastics, comprehensively defined by the American Society for Testing & Materials (ASTM) as plastic "capable of undergoing biological decomposition in a compost site as part of an available program, such that the plastic is not visually distinguishable and breaks down to carbon dioxide, water, inorganic compounds, and biomass, at a rate consistent with known compostable materials (e.g. cellulose) and leaves no toxic residue."
It lays down three requirements for something to be called compostable. It must:
- Biodegrade - break down into carbon dioxide, water, biomass at the same rate as cellulose (paper).
- Disintegrate - the material is indistinguishable in the compost, that it is not visible and needs to be screened out
- Eco-toxicity - the biodegradation does not produce any toxic material and the compost can support plant growth.
While this can be more advantageous to the earth and the environment than biodegradable products, it's important to note that these products generally only compost at certain temperatures.
Thus they might not even break down in your outdoor compost heap, you actually have to send them to a professional composting facility, should there even be one in your area.
World Centric (a sustainable compostable product manufacturer) has put together a chart estimating composting times of different materials (based on their products), but as to whether all compostable products can do this is up for debate (and testing).
Biodegradable plastic packaging and products or degradable plastic
Last but not least there is also degradable plastic. As defined by World Centric, Degradable Plastic will undergo a significant change in its chemical structure under specific environmental conditions resulting in a loss of some properties.
However, they caution, there is no requirement that the plastic has to be degrade from the action of "naturally occurring microorganism" or any of the other criteria required for compostable plastics.
In fact, most of the products using the label degradable, degrade as result of physical and chemical impact (i.e. fracture into smaller pieces of plastic), which doesn’t seem that eco-friendly to me.
Says World Centric “A plastic therefore may be degradable but not biodegradable or it may be biodegradable but not compostable (that is, it breaks down too slowly to be called compostable or leaves toxic residue)”.
Ultimately, I believe the best solution to reduce our impact on earth is clear - bring your own reusable bags, compost your kitchen waste, recycle anything else, consume less, use less and throw less away.
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