Biodegradable plastics are designed to decompose naturally, making them a less harmful product to the environment. Due to that, they are perceived as more eco-friendly and becoming a popular replacement as consumers turn to green alternatives.
However, they might not be that fast to decompose and may need industrial composters to break them down after use. Given humans' track record, it is far from guaranteed that these plastics will make it to these facilities and may end up in places that they should not.
Are Biodegradable Plastics Better for the Environment? Here's Why It Should Not Be Mixed With the Compost
Bioplastics: Are They A Better Option?
Biodegradable plastics are different from the once-prized plastic that never decompose. These types of plastic can completely break down naturally in the environment and are a source of carbon dioxide for microbes. According to Phys.org, they are composed of materials that can be turned into compost.
However, only a minority of these plastics are compostable at home. These biodegradable plastics are made up of polyhydroxyalkanoates and will fully decompose in natural environments, like soil, seawater, and landfill, within a few months to years.
While others made with polylactic acids, such as those used in coffee cups, need to be processed in an industrial composting environment to break down that uses high temperatures and lots of microbes.
Many biodegradable plastics are not "bio-based" and are not derived from renewable carbon sources like plants. They could be made from petroleum-derived materials.
More so, bio-based plastics are not all biodegradable. The best example is polyethylene which is a kind of polymer produced globally and widely used in plastic bags. Despite being derived from the ethanol produced by cane sugar, it is still unable to break down and decompose naturally.
ALSO READ: Biodegradable Plastic Cutlery Developed to Transition Into Insulation Foams During Decomposition
How Long Do Biodegradable Plastics Decompose?
Most plastics are forever and they are clogging up the planet, so people think biodegradable plastics are ideal. But how long do they naturally decompose?
According to Science Focus, these plastics take three to six months to decompose fully, which is faster than their synthetic counterparts, which take several hundred years. But then again, the rate they break down depends on their composition, temperature, and amount of moisture present.
But they are not as clean or green as they are marketed because even as they disintegrate gradually in the presence of oxygen, they turn into a sludge of toxic chemicals that still poisons the environment. On the other hand, bioplastics made from cornstarch are plant-based and merely give off carbon dioxide that has been locked in by the plant matter they originally came from.
Better Standards for Labeling Are Needed
According to the BBC Future, the biggest sector needing biodegradable plastics is the food service - from the coffee cups to sandwich packaging and takeaway containers.
Bio-based and Biodegradable Industries Association (BBIA) managing director David Newman said that he hopes to see teabags, fruit stickers, condiment sachets become compostable by law so that leftover food and the plastic that comes with it can be processed simultaneously.
He added that the industry too could perhaps turn to bio-lubricants to keep machines running smoothly than use fossil fuel-based options. In that way, even if they spill all the machine oils, it will not damage the environment.
The only problem now is making sure that compostable packaging could fully compost since oil might break down in the environment, but plastics do not.
RELATED ARTICLE: First True Biodegradable Plastic Disintegrates in Heat, Water in Just a Few Weeks
Check out more news and information on Plastics in Science Times.