We believe that compostable bioplastics are usually made from plant-based raw materials, such as plant starch, sucrose, cellulose (wood fiber), and lactic acid, as a solution to many of these problems. Polylactic acid (PLA) is a bioplastic that is usually derived from animal feed corn and can be used for many different purposes, including cold drink cups, deli and takeaway containers, and fresh produce packaging. Sounds good, right? At least in theory. But in reality, the situation is more complicated. Today, we will explore the advantages and disadvantages of these "corn plastics."
Advantages of polylactic acid (PLA) or "corn plastic"
PLA comes from renewable resources
One of the main problems with petroleum-based plastics is that they are obtained from oil or natural gas, which is only available in limited quantities worldwide. Eventually, these fossil resources will be exhausted. PLA comes from corn, which is a resource that can be updated every year.
Where there is a commercial composting facility, PLA plastic is compostable
It is estimated that traditional plastics may take centuries to break down, and may never break down into natural elements. This is especially true when these products are eventually landfilled, completely reducing sunlight and air exposure. PLA, on the other hand, can be broken down into natural elements in available commercial composting facilities.
If incinerated, PLA will not produce toxic fumes
For decades, we have been warned that incineration of traditional plastics can release dangerous chemicals. As a bio-based material, PLA plastics would not produce these toxic fumes if they were eventually incinerated instead of finding commercial composting facilities.
Disadvantages of polylactic acid (PLA) or "corn plastic"
PLA production depends on large crops
Although corn used to make PLA is a renewable resource, many have pointed out that the fields used to grow these crops can be used to create food for the world's population. They do have opinions, but it is important to remember that the bioplastics industry is still young. The industry's long-term plans include identifying effective ways to make PLA plastic from agricultural waste, such as stems and stalks, which could lead to products that are not suitable for consumption as bioplastics.
PLA plastic can only be composted in commercial composting facilities
Unfortunately, most PLA plastics don't break down into natural elements in your backyard compost pile. Instead, these products need to be sent to a commercial composting facility for processing. Currently, such facilities are limited in the United States. However, as the industry develops, we believe that commercial composting infrastructure will follow. Disposing of PLA plastic products in landfills is an acceptable end-of-life option.
Improper disposal of PLA plastic can contaminate the recycling process
Regardless of whether there is a commercial composting facility locally, many PLA products will eventually be mixed with traditional recyclable plastics. Because they are chemically different from traditional plastics labeled # 1 to # 6, they can cause problems during the recycling process if the products are not properly sorted before they begin recycling. PLA products are identified as No. 7 (other plastic) plastics for recycling.