Biodegradable Packaging and Its Importance for our EnvironmentMay 25, 2015
“Australians use six billion plastic bags every year!” Packaging is primarily plastics because it affords protection from the elements and handling and is cheap to produce. The primary issue is, it is such a durable product that it nearly lasts forever – in landfills, sewers, and as litter. As a result, packaging has become a major environmental problem. Compounding this, is the fact that non-renewable coal, oil, and natural gas resources are used in the manufacturing of the material.
Enter the critical need for biodegradable packaging. Living organisms decompose biodegradable items into simple substances that can eventually be overtaken and consumed into the environment. Globally, each country has its own specifications that determine the degree an item may be biodegradable. Typically an item must decompose between 60 – 90% within 60 to 180 days of being placed in a typical composting environment to be defined as being “biodegradable.”
Traditional plastic packaging is not considered biodegradable because plastic’s polymer molecules are too tightly-bonded together to be decomposed within the defined period naturally by living organisms. Plastic materials composed of natural wheat or cornstarch polymers, however, are subject to rapid breakdown by microbes.
Types Of Biodegradable Packaging:
Paper made from pulped cellulose (from managed plantations) is preferred for making paper cups and bowls, which are coated with a plant-based bioplastic that can be composted, rather than a plastic water-proof lining.
Transparent bioplastics (PLA) made from plants rather than oil provides a better source for cutlery, cups, and waterproof paper cup coating. Plastarch material (PSM) is a starch-based bioplastic / polypropylene blend that may also be used for cutlery and disposed of with general waste.
Checkout and refuse bags made of ecopond (a synthetic biodegradable plastic combined with plant-starch) meets Australian Certification Standards. They biodegrade more quickly than conventional plastic bags when they end up in the environment or landfills.
Polyethylene terephthalate (PET) and Polypropylene (PP) are plastics made from fossil resources and is the most recycled plastic in the world. Typically used for takeaway container lids, they can be recycled along with empty water and cold drink bottles.
Compost maximizes the environmental benefit of biodegradable plastics. A major problem is that organic waste that might naturally decompose is typically mixed in with non-degradable plastic packaging. It is costly to separate them, so, as a result, everything sits in the landfill together.
Statistically, organic waste comprises nearly half of landfill components in Australia. The increased use of biodegradable packaging can more cost effectively and environmentally allow organic and packaging material to be composted together. The resultant compost can then be channelled into plant production.
Sewage is a good biodegrading environment. Decomposing microbes and high levels of nitrogen and phosphorous activate sewage sludge that readily converts most of biodegradable polymer into carbon dioxide. What remains, enters is converted to methane. Flushable biodegradable plastics can adversely impact wastewater treatment plants. However, degradable polymers do not limit the sewer systems.
Most biodegradable plastics degrade in composting and soil disposal environments in a shorter time than traditional plastics. However, they do not degrade well in a dry landfill unless they contain sensitizers and pro-oxidants (manganese stearate or cobalt stearate). Biodegradable plastics contribute to landfill gas production as an alternative energy source. Conversely, biodegradable plastics increase greenhouse gas emissions when there is no gas utilization system available.
Water temperature directly affects the biodegradable rate in marine environments. Cold waters do not decompose plastic material that can endanger marine life a long time. Similarly, plastic litter can cause trauma to wildlife that ingest discarded packaging.
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