Bioplastics are derived from biomass sources like vegetable fats and oils and corn starch. They can also be made from plastic bottles and other agricultural by products using micro organisms.
There is much debate about sustainability and environmental virtue of Bioplastics. On the one hand they use sustainable sources, and they do break down however there is great concern that for bioplastics to sustain (by themselves) the market that they currently share with typical plastic it could result in an accelerated rate of deforestation and soil erosion. Likewise water supplies could also be hugely affected.