Tackling End-of-Life Issues for Bio Plastics

This post is part of a blogging series by economics students at the Presidio Graduate School’s MBA program. You can follow along here.

By Lindsey Wedewer

Bio-based plastics have the potential to be a real game-changer in the world of sustainability. Alternatives to petroleum-based plastics have been springing up all over the world in the last several years. One of the most widespread and promising materials emerging is polylactide, or PLA, which is made from plant-based feedstocks such as corn, rice, sweet potato and sugar beet. PLA can be composted or completely reused, and the production process is cleaner than that of traditional plastic. PLA has broad implications for sustainability, as it has the potential to eliminate the need to utilize petroleum – a finite, non-renewable resource – for plastics, and avoids the post-consumer accumulation problems related to conventional plastics. PLA is being accepted in a number of industries, including packaging, automotive, medicine and textiles, though the production volume in the US is still low compared to that of its petro-based counterparts.

Although PLA is manufactured with two end-of-life options in mind, the material rarely meets its intended ends. There are infrastructural limitations to both composting and recycling which create an unfortunate end-of-life dilemma for PLA – even though products may be disposed of in a recycling or composting bin, they still have a chance of being landfilled. This presents a problem for PLA producers – without supportive composting and recycling infrastructures, a biodegradable and recyclable product is a difficult sell.

Although PLA readily biodegrades in a controlled setting such as a commercial composting facility, few of these facilities currently accept biodegradable plastics. Those that do often have rigid specifications for the material they will accept. For example, Cedar Grove Composting, the only facility of its kind in Seattle, requires that biodegradable materials be tested and become certified before they will be accepted as compost. Oftentimes, when PLA does end up in composting streams, it is extracted, due to its similar appearance to traditional plastic.

Even more efficient than composting, PLA can be recycled through a chemical conversion process, returning the post-consumer product to its base material of lactic acid. This allows it to be reproduced into PLA with the same properties as its virgin predecessor. Although the potential here to create a cradle-to-cradle scenario is great, there are no widespread means in the US to collect, sort or recycle PLA. Again, PLA can look quite similar to conventional plastics and since 70% of recycling is still sorted by hand, a hand-sorter is not necessarily able to identify the differences. Thus, the sorting of PLA requires expensive near infrared technology to properly differentiate it in a recycling station. Although some recycling centers are equipped with this technology, others are not and adopting it would require a significant investment.  At the end of the day, recycling facilities will not start a new material collection or invest in any new technologies unless there is consistent volume to justify it, and that critical volume of PLA has yet to be reached.

Thus, we find ourselves in a “catch-22.” Composting facilities are not seeing enough post-consumer PLA volume to alter their practices and similarly, recycling centers are waiting for PLA volume to increase so they can rationalize collection. Meanwhile, bioplastics producers are hoping for improved disposal infrastructures so they can tout the positive end-of-life options related to their products in a meaningful way. This would attract business and lead to a subsequent increase in the volume of post-consumer PLA.

Although PLA has enormous potential to succeed in the US market as an alternative to traditional plastics, the end-of-life dilemma remains a looming obstacle that will need to be addressed before its true cradle-to-cradle nature can be realized.