Apparently there are very distinct characteristics of these three terms: Compostable, Biodegradable, and Degradable. First off, plastics can be made into any of these three categories which is wonderful news for the future of this planet (well that is if everybody decided to go the compostable route). To be compostable, plastic must undergo strict regulations during its degradation. It must: biodegrade (break down into: water, carbon dioxide, and biomass at the same rate as paper); disintegrate so that it is no longer distinguishable within the mass of broken down materials; and it cannot leave any toxic residue after the process of composting. Oh yeah, and the most important part, it must be capable of future plant growth. As for biodegradable plastics, they just need to be able to be broken down by microorganisms like bacteria in a natural setting. With this type of plastic, though, there is not yet a requirement for how long it takes for the process for biodegrading to occur, so theoretically it could take many years to break down and still be called biodegradable. And degradable simply means it will undergo some change in its chemical make-up overtime, but there is no regulation on how long it takes to break down or how much of a toxic foot print it leaves on the Earth. All of this information stated above can be found in the first link below.
Making plastics compostable is a wonderful step in the right direction, but is creating compostable plastics really helping the environment? When I first noticed compostable plastics at the hotel I work at, we were able to sort the utensils, cups, etc. into the compost bin. However, it was only a few months later when the waste management company my work goes through told us to no longer throw those into the compost bin, but rather they will have to be placed in the trash. Doesn’t that defeat the purpose? Yes and no. First of all compostable plastics will still go under biodegradation where it will break down into carbon dioxide, water, and biomass over time. It will take longer than in these processing plants, but it will still occur. The problem then is these items are being thrown into the trash where they will sit in a landfill and not be recycled as per their intended purpose; no beneficial plant production from its decomposition. I also recently walked into a health-food grocery store where the cafeteria had three or four bins for sorted food waste. There was a sign over the compost bin, however, that said to not place the utensils (compostable plastics) into the compost bin and rather to place them in the trash. I feel that creating compostable plastics is a step in the right direction for sure, and the thinking is righteous, but how can we create a more efficient way to get rid of these items? Why are they no longer allowed in with the other compostables?
One huge problem lies in the misunderstandings of identification of compostable plastics by not only the home consumer, but by the larger companies that run facilities to break down and recycle these products. A good step would be to make sure all products are easily recognizable so that the recyclers can place items where they need to go. Compostable plastics are still in their infancy and there are kinks still yet needing to be worked out.