The solution to the world’s single-use plastic crisis isn’t an easy one. We can all agree that a material used once and then takes over 500 years to decompose is not the most eco-friendly choice for packaging. But until a substitute comes along that is just as durable—and affordable—as plastic, manufacturers likely won’t budge.
Enter polylactic acid bioplastic (PLA for short). PLA looks and acts a lot like the regular plastic of the polyethylene or polystyrene variety, except this material is made from the sugars in crops like corn or sugarcane. The end result is biodegradable, carbon-neutral, and you can even eat it. But as much as we desperately wish PLA could be the much-needed solution to our single-use plastic problem, it’s not.
That’s not to say there isn’t a time and place for PLA. Compared to a typical plastic product—91% of which won’t get processed at a recycling center and will instead pollute our land and oceans—something that can instead biodegrade sounds appealing.
“PLA is an answer to some applications where its biodegradable nature helps material recycling,” said David Newman, managing director of the European Circular Bioeconomy Policy Initiative. He explained that humans’ largest waste stream is food waste, not plastic. While discarded plastic certainly takes its toll on the earth, food waste does so in a way that’s not quite as noticeable: with emissions.
If all food waste were collected and united to become its own country, it would be third only behind China and the United States in terms of greenhouse gas emissions. Food waste accounts for 8% of the entire world’s emissions.
“As a society, our priority should be to reduce food waste, collect it separately, and treat it to stop errant methane emissions,” David said. “To get all that food and garden waste into treatment and back to soil cleanly, we need materials that ensure it’s not polluted with plastics. We need materials that mimic biowaste and compost along with them. PLA does just that.”
In the right conditions, PLA will not only break down in food waste, but it has the potential to add nutrient value to the soil. Furthermore, a 2017 study found that switching to PLA could reduce greenhouse gas emissions by 25 percent. So it seems pretty logical that, when compared to something like polyethylene—which gets made from petroleum or natural gas—bioplastic derived from crops that can biodegrade is pretty enticing.
Unfortunately, PLA isn’t the holy grail that will put an end to our reliance on plastic. While they produce fewer greenhouse gases, a study from the University of Pittsburgh revealed they generate more pollution due to pesticides and fertilizers. Plus, who decides in the first place that crops should get utilized for creating bioplastic rather than feeding the 690 million undernourished people worldwide?
At the end of its life cycle, PLA is biodegradable—but what’s not as readily advertised are the specific requirements for this to happen. The bioplastic will break down in an industrial composting facility that reaches 140 degrees Fahrenheit and is continuously provided with digestive microbes. Tossing a piece of PLA in your home compost bin won’t do the trick. That also assumes that the infrastructure exists to accept these items, which few cities have. Additionally, if PLA doesn’t make it to a facility and instead ends up in a landfill, it could still take hundreds of years to decompose there.
For manufacturers, designers, and brands to tout bioplastic’s benefits while brushing these caveats under the rug is irresponsible. By not being transparent, bioplastic products become a prime example of greenwashing. Brands market them as better for the environment despite not having adequate systems to process the materials.
Does this mean that PLA is always a terrible option? No. It’s a carbon-neutral option made from renewable resources that might sometimes be the answer. “PLA is not the panacea for all. It needs to be used judiciously, and when you know the planned waste stream is set up to deal with it properly,” advised Sian Sutherland, co-founder of A Plastic Planet. “To use PLA for something like single-dose plastic sachets containing ketchup or other foodstuffs is a good use of PLA as it takes the residual food waste (ketchup) into the right waste stream.”
The problem, Sian said, is that we’re all sitting around and hoping some new kind of plastic will come along that looks and feels like regular plastic but doesn’t harm the environment—and it’s time we let go of that dream. The solution will not be that simple. Instead, it will require some creative thinking and a combination of many different solutions to change systems and bring new materials into the fold.
“One day, there will be no waste as we will have worked out how to re-use every material differently,” Sian said. “That’s the future we need to rush towards, and designers are the key to this. They must be informed, inspired, and brave enough to push clients beyond easy fixes.”
