Average usage time of a plastic bag is 12min OR facts about bioplastics
SO it's becoming complicated. Whats the difference? Bioplastic, biodegradable, industrially compostable, home compostable - these are some of the alternatives that can be found apart from the traditional petroleum-based plastics made from non-renewable resources.
Let's simplify and make sure that we treat the plastics correctly when we recycle or dispose of them. Personally we just like to avoid them as much as possible!
What is BIOPLASTIC? This particular feature in the word “bioplastic ” is indicated by the prefix “bio”, without indicating that the final product will be biodegradable and will not harm the environment.
Instead the "bio" part refers to the material this plastic is made from, usually it is corn; wheat or other grains; potato starch; sugarcane.
Bioplastics are different, some can contaminate the soil for more than 2 centuries just like petroleum based plastic. But others (label as "compostable"), thanks to active additives, completely decompose within 12 months.
Biodegradable plastic DOES NOT EQUAL Compostable Plastic
Biodegradable refers to a material breaking down with the help of microorganisms. These are traditional polymers with biodegradable additives that accelerate the degradation process in vivo. There is no time limit and this plastic can leave behind toxic residue. The research showed after 3 years biodegradable plastic bag could carry same shopping weight as a conventional plastic bag.
Modern recycling technologies do not have the ability to separate biodegradable polymers from the general flow of plastic that is recycled. So if biodegradable plastic is thrown in a "bin for recycling" , it a) does not completely degrade and b) reduces the quality of the other recyclable materials and the bags become impossible to recycle.
Compostable refers to a material capable of breaking down into carbon dioxide, water, and biomass at the same rate as cellulose, but also methane (another important greenhouse gas that traps heat in the atmosphere) and some inorganic compounds. Compostable plastic must also disintegrate and become indistinguishable in the compost and CANNOT leave any toxic material behind.
Being a type of BIOPLASTIC, compostable plastic is made from destructured potato starch, corn starch, cellulose, sugar cane. Firstly the price of making this material is high. Secondly the ethos of using food to synthesize plastic is questionable: growing huge amounts of crops to turn them into disposable items is a completely irrational use of the planet's resources (remember: the average usage time for a plastic bag is 12 minutes!).
Industrial compostable vs Home compostable
Industrially compostable plastic needs the environment set up in a plant where the plastic is ground down and churned in higher temperatures to achieve the compost.
It is possible compost some bioplastic at home where it will take longer than at the plant.
European legislation says that 90% of compostable plastic must decompose in 180 days. The question must be asked is what happens to the remaining 10%? It remains as microplastics in the compost.
Watch out for the Austria TUV label that states what type of compostability the plastic has. It's important to state that compostable plastic WILL NOT biodegrade in a landfill, it should be thrown out with your food waste if the council has the infrastructure to sort it. One simple reason why they won't decompose is because they need air, moisture and sunlight to break down properly. Usually, landfills tend to bury waste and that deprives these plastics from these necessary elements. In addition, nickel, manganese, iron and cobalt are added to ensure biodegradation of plastics. In the final material, their content is small, but with a large number of packages, these are significant volumes, which ultimately will have a negative impact on the soil and groundwater.
So if you buy compostable plastics then it is up to you to ensure that they end up in the correct environment.
Biodegradable and compostable plastics DO NOT mix with recyclable plastics
And this means that unfortunately it cannot go into the blue lid bin that gets put out with the recycle plastics. Not all Industrial recycle/compost plants are able to sort bioplastics from recycle plastics.
Are bioplastics safe?
Even though most plastics made from plants are free of pthalates or bisphenol A (BPA), the recent research published in Environment International in September 2020 showed bioplastics could be as toxic as conventional plastics. Lisa Zimmermann, the leader of the research writes "Our study demonstrates that bio-based and/or biodegradable materials available on the market are just as toxic as conventional plastics with regards to the chemicals they contain. This highlights that the positive connotation of “biological” or “sustainable” materials does not extend to chemical hazards. Accordingly, our ﬁndings imply that in order to develop bio-based/biodegradable materials that indeed outperform conventional plastics, sustainability and chemical safety aspects must be addressed alike".
I hope this clears things up a bit, so it's worth considering the hassle involved when buying a product wrapped in plastic. I guess I wrote this article more for my sake as this conversation comes up often in the shop. I know that rather than spending my time studying all the fine print related to the food and the packaging, I rather just leave out the packaging part and just get the product loose.