Compostable and biodegradable plastics sound pretty similar, but they’re entirely different. It’s important to understand these differences to avoid risky exposure to toxic chemical residue.
Let’s compare and contrast compostable and biodegradable plastics.
What Is Biodegradable Plastic
Biodegradable plastic is sometimes also called photodegradable or oxydegradable plastic. It is similar to traditional petroleum based plastic but breaks down faster.
The addition of certain additives during manufacturing compromises the structure of the polymers in biodegradable plastic. Traditional plastic can last hundreds of years before it goes anywhere, so this is a plus. It isn’t a magic solution, however, and it isn’t risk free.
The problem arises when someone mistakes the term biodegradable for compostable. As biodegradable plastic breaks down, it leaves behind traces of chemicals that are toxic. It can also break apart leaving small bits of plastic embedded in composted soil. This isn’t safe for plants or animals.
These types of plastic products don’t exactly biodegrade at all. They aren’t as hardy as traditional plastic, but they won’t simply return to the environment. This can be dangerous for anyone new to composting or who hastily takes the word ‘biodegrade’ at face value.
What Is Compostable Plastic
Compostable plastic is sometimes called bioplastic. The most recognizable variety of this innovative new plastic is called Polylactide acid or (PLA). PLA is made with corn starch and does not contain petroleum. Cellulose is also used in the production of plant based plastic.
Bioplastics function the same way regular plastic does in terms of consumer use. They look, feel, and perform the same way as the plastic you’re used to. There is no adjustment necessary. Their impact is significantly smaller, however.
Because the chemicals used to create them are gentler to the environment, they can be composted and do not leave behind and toxicity to the soil. You can treat them the same as you might any organic material or cardboard.
The fact that bioplastics are created from plant material means that the product creates no net gain in carbon output to produce and release less greenhouse gas during decomposition. PLA and other corn based bioplastics do raise some concern over the land needed to grow the additional corn necessary for production, however.
It isn’t perfectly green, but it’s better than old fashioned petro-plastic by leaps and bounds.
How Does Compostable Plastic Work?
With PLA in particular, the cornstarch molecules absorb water over time. They swell and fracture which speeds up the breakdown of the item. Cellophane, which is made from cellulose, breaks down rather quickly in as little as 10 days to a month.
Food storage containers, crisp bags, disposable cutlery, and other disposable items can be made with compostable plastic and then tossed out in the compost bin to slowly dissolve. From the earth and to the earth, the cycle is complete.
This is not only a good move for the environment, it also allows individuals to contribute to eco friendly practices in their own home. In this way, composting is a wonderful addition to other earth friendly habits your family exercises, such as bag bans or ceramic or glass food storage for leftovers.
Compostable Plastic- A Better Way
The most important takeaway from this article is that it is simply not safe to compost biodegradable plastic. Until labels are made clear, be warey of any plastics that reference photodegradable or oxydegradable plastic as well. You can lower your consumption by simply slipping a reusable shopping bag into your purse or vehicle and using it.
When you can, opt for compostable plastic products and bring them home to toss into your compost bin. You’ll be left with soil as safe as your other compostable materials, like coffee grounds and eggshells.
If you’d like to get active in the fight against petroleum based plastics, vote with your dollar by purchasing products that are as gentle on the earth as possible. Over time, manufacturing companies will get the message that petro-plastic is history.