Bioplastics are a form of plastic that come from renewable sources, such as corn, vegetable oil or corn starch, for example. They differ from the standard plastics, made from petroleum, that we have come to depend on in society over the past several decades. For example, many clear plastic containers today are made from PLA or polylactic acid – a resin produced from corn. NatureWorks in the USA is the world’s largest producer of PLA. Their containers are compostable in industrial composting facilities only. PLA is also used in cups and containers as an impermeable liner.
Scanning the Internet, there has been quite the debate over the past few years on whether or not corn plastic actually makes us better off than our conventional petroleum based PET. So here is a condensed list derived from the more prominent sources* that summarizes some of the key advantages and disadvantages of corn plastic:
Advantages of PLA
- Derived from corn which is a renewable resource
- PLA products are compostable in industrial composting facilities
- PLA is cost competitive with regular petroleum-based resins such as PET and most likely cost advantaged in the future given rising petroleum prices
- Producing PLA uses 65% less energy than producing conventional plastics
- Producing PLA creates 68% fewer greenhouse gases than producing conventional plastics
- PLA contains no toxins
- From a safety perspective it will not blow up like oil might
- PLA is only compostable in industrial composting facilities – access is limited as only few sites in the USA exist (113+)
- PLA in large amounts may interfere with conventional composting because the resulting polymer will make the compost wetter and more acidic
- Consumers will dump PLA in with their regular PET recycling which can contaminate the PET recycling stream if it happens in large quantities
- Material Recovery Facilities (MRFs) have to pay to sort out PLA and pay again to dispose of it
- Because of the lack of infrastructure, the majority of PLA packaging is likely to still end up in landfills
- Most of the corn used to produce PLA is genetically modified
- Some individuals raise morality concerns in using food for packaging if so many people in the world are starving
In addition to PLA, there are a number of other renewable packaging alternatives hitting the markets, most notably, agricultural fiber products produced using natural fibers such as bagasse, bamboo, bulrush, and palm fiber. They differ mainly in that they can be composted at home, not requiring an industrial composting facility. While they have many advantages, agricultural fiber based products are not necessarily direct substitutes to PLA. For example, they cannot be used for high moisture applications, such as cups, without partnering with PLA or other such product to offer a barrier coating.








