Biodegradable plastic can seem like a great alternative to standard plastic products. However, there is a lot of controversy over the wide and varied claims as to what biodegradeable means. The main problem is that there are no clear guidelines governing these claims and it is left to consumers to decide what they feel constitutes biodegradable and as consumers we don't neccessarily have the scientific knowledge, resources or time to work it all out.
Some biodegradable plastics are merely standard plastic with a chemical added that makes them break down into fragments faster, but like normal plastic will only break down so far where they can easily enter the food chain. Plastic only ever breaks down into fragments and never completely disappears. Often these fragments find their way into oceans and waterways where they are mistaken as plankton by fish. The other problem is that these smaller fragments tend to attract molecules to themselves and end up being significantly more toxic than when initially produced!