When it comes to plastic, biodegradable and compostable are often used interchangeably, but there is a slight difference between the two terms. Granted, they are designed to decompose faster than the traditional petroleum-based material, which will only disintegrate after ten years if it ends up in the landfill.
Here is the difference: every compostable plastic is biodegradable, but not all biodegradable plastic is compostable.
But they both break down, don’t they? So, why make the distinction?
In Australia, all compostable products must first pass the criteria set by the Standards Australia Committee. Manufacturers must secure two certifications, namely Commercial Composting Standard AS 4736 and the Certified Home Compostable AS 5810.
The guidelines include the toxicity level of the plastic, the solid contents, and the degradability. It is not enough that the biodegradable packaging decomposes according to the label. There are several other factors at play. For instance, the plastic should break down into a byproduct to help enrich the soil using a mixture of oxygen, solids, moisture, and heat.
A biodegradable plastic will only disintegrate but would not add value to the soil.
It is why you should also look for the compostable logo when you buy biodegradable packaging for your compost at home.
How Long Before Compostable Plastics Disintegrate?
Different biodegradable products have varying degrees of decomposition time. On average, they break down within six months. The commercially available single-use plastics now (non-biodegradable) will disintegrate in 12 months to 24 months. They are still far better compared to the technology more than a decade ago. Back then, plastic bags were designed to decompose for 500 years. Yes, plastic bags dumped in the landfill in the year 2000 won’t break down until the 25th Century.
Now, you have more options when it comes to compostable biodegradable packaging. For example, some products will decompose and enrich your garden or vegetable soil at home within 120 days. The breakdown cycle is even faster when dumped in a commercial compost as these plastics decompose in 90 days.
Are Poly Mailers a Good Alternative to Compostable Plastics?
Before compostable plastics, poly mailers were the standard. However, poly mailers that are derived from petroleum won’t decompose until 12-16 months. In comparison, compostable plastics will break down in 90 days. It is why more and more Australians are using compostable mailers as an alternative to poly mailers.
Can You Throw Dump These Compostable Plastics in the landfill?
Sure, but it would really defeat the purpose of purchasing compostables in the first place, wouldn’t it? Biodegradable plastics may end up at the landfill, and it would be no problem because they will biodegrade as designed. However, compostable plastics need some ingredients to break down properly. These include sunlight, air, moisture, and the like. When you bury the material, it will not degrade.
Why Buy Biodegradable and Compostable Plastics?
We buy compostable plastics to avoid putting more strain on the environment. For example, Australia throws away plastics with wild abandon, the volume of which can only be described as colossal. For example, according to the World Wildlife Fund, each Aussie is responsible for 130 kilos of plastics every year, which already includes single-use and bottles. Unfortunately, they end up in waterways and finally make their way to the oceans—all these factors make compostable plastics the go-to option now.
