I Forgot My Travel Mug…

I always start my day with a fresh brewed cup of coffee at home, brewed in my regular drip coffee maker. It’s nothing special, but it’s what I like. On the rare occasion that I miss my weekend grocery trip and run out of creamer, I stop into the small market by my work and fill up on some locally roasted brew. Sometimes I remember to bring one of my travel mugs, which is great since they only charge 99¢, but on the mornings when I’m rushing out the door, I usually forget. This week, I had one of those busy mornings and forgot my reusable cup. It was a particularly warm and muggy morning, so I opted for an iced coffee, even worse because of the plastic cup right?

As it turns out, the store sources Greenware containers, which are plant based and compostable, as well as paper straws. I have to say, I felt a sense of relief knowing that even though I was using disposable products, they were sustainable alternatives to traditional plastic products. I want to emphasize that  I’m not suggesting this makes the use of disposable containers sustainable, we all know the hierarchy of reduce, reuse, and recycle. However, on the chance that you forget your reusable container, it’s nice to know that biodegradable options are available.

Greenware is made from Polylactic acid (PLA) biopolymer, which I will discuss moving forward from a generic standpoint and not solely regarding the Greenware brand. PLA is typically made from corn, which is also used to make the coating on some paper cups. A 2004 study evaluated performance of PLA food containers alongside polyethylene terephthalate (plastic) and polystyrene (foam) food containers. Results from the study indicated that food containers made from PLA exhibited similar properties and durability, thus making it a viable alternative to traditional disposable containers¹.

Comparison of Different Material Single Use Cups

	Polyethylene or Polystyrene	Paper	PLA
Energy to Produce2,3	104 MJ/kg	66 MJ/kg	54 MJ/kg
Time to break down	Depending on type of plastic it can take 10s to 1000s of years	20 years in a landfill	45-90 days in a commercial composting facility.
Disposal Methods	Recyclable	Recyclable or compostable depending on coating material (wax, plastic, pla)	Can be composted but some studies show recycling to be more efficient4

As I will touch in more specific blog posts, I believe sustainability will be most readily achieved by having bottom-up and trickle down processes. The bottom-up process is the demand by the consumer for eco-friendly and sustainable alternatives, such as bringing reusable cups for their coffee even though refill rates may not be cheaper. This will in turn drive governments and corporations to comply with customer demand. The top down process consists of companies putting more sustainable systems in place such as sourcing bio-based plastics instead of traditional petroleum based plastics, and reducing costs of these sustainable alternatives to make the sustainable alternatives more easily accessible.

What are the take aways:

1. Polylactic acid (PLA) biopolymer is a plant based or “bio-plastic” that is available for single use containers in the food industry
2. Studies show that PLA is a viable alternative to fossil fuel derived plastics, but that while it can be composted, recycling may be the more efficient disposal method for PLA.
3. Reduce, reuse, and recycle will always prevail when it comes to sustainability. However, that doesn’t mean we shouldn’t implement more sustainable options when and where possible. Top down and bottom up efforts are both needed to drive sustainability forward.

Citations

1. Auras, R., Singh, S., & Singh, J. (2006). Performance Evaluation of PLA against Existing PET and PS Containers. Journal of Testing and Evaluation,34(6), 100041. doi:10.1520/jte100041
2. “Reusable vs. Disposable Cups.” Institute for Life Cycle Energy Analysis, 1994, sustainability.tufts.edu/wp-content/uploads/Comparativelifecyclecosts.pdf.
3. Vink, E. T., Rábago, K. R., Glassner, D. A., & Gruber, P. R. (2003). Applications of life cycle assessment to NatureWorks™ polylactide (PLA) production. Polymer Degradation and Stability,80(3), 403-419. doi:10.1016/s0141-3910(02)00372-5
4. Harst, E. V., & Potting, J. (2014). Variation in LCA results for disposable polystyrene beverage cups due to multiple data sets and modelling choices. Environmental Modelling & Software,51, 123-135. doi:10.1016/j.envsoft.2013.09.014