What are biodegradable plastic bags now being made from?
Plastic bags have long been an environmental concern due to their long lifespan and potential to accumulate in landfills and oceans. In recent years, there has been a growing demand for eco-friendly alternatives to traditional plastic bags. One solution that has gained popularity is biodegradable plastic bags. These bags are designed to break down more quickly and safely in the environment, reducing their impact on the planet.
But what exactly are biodegradable plastic bags made from? In this article, we will delve into the materials commonly used to create these bags and explore their benefits and limitations.
1. Polylactic Acid (PLA): One of the most common materials used in biodegradable plastic bags is polylactic acid, also known as PLA. PLA is derived from renewable resources such as corn starch or sugarcane. These feedstocks go through a process called fermentation, where they are converted into lactic acid, which is further processed into PLA pellets. These pellets can then be molded into various bag shapes.
PLA-based bags have gained popularity due to their biodegradability and reduced carbon footprint compared to traditional plastic bags made from fossil fuel-based polymers. PLA bags can decompose in industrial composting facilities within 3-6 months, significantly faster than conventional plastics.
However, it's essential to note that PLA bags require specific conditions to break down efficiently. They need exposure to high temperatures and moisture, which are typically found in industrial composting systems. In a regular landfill or marine environment, PLA bags may not biodegrade as quickly or effectively.
2. Starch-Based Plastics: Starch-based plastics are another common type of material used in biodegradable plastic bags. They are primarily made from renewable resources like corn, wheat, or potato starch combined with a biodegradable polymer. These bags are often referred to as "compostable" as they can fully break down in composting facilities, leaving no harmful residues behind.
Starch-based bags are lauded for their low environmental impact and their ability to be composted into nutrient-rich soil. However, it's crucial to distinguish between "compostable" and "biodegradable" in this context. While compostable bags can break down in composting conditions, they may not necessarily degrade in a regular landfill or marine environment.
3. Polyhydroxyalkanoates (PHA): Polyhydroxyalkanoates (PHA) are a class of biodegradable polymers produced by bacteria through fermentation. PHA-based bags are considered to be fully biodegradable and can break down under various environmental conditions, including natural soil, water, and marine environments.
PHA bags offer an enticing alternative to traditional plastics, as they can degrade without producing harmful microplastics. They can also help alleviate concerns about plastic pollution in oceans and water bodies. However, PHA bags are currently more expensive to produce than traditional plastics, hindering their widespread adoption.
4. Other Materials: In addition to the aforementioned materials, other biodegradable plastic bags can be made from a blend of biodegradable polymers and additives. These additives can help enhance the biodegradation process or provide additional functionalities such as strength, flexibility, or clarity.
It's worth noting that not all biodegradable plastic bags are created equal. Different materials and manufacturing processes can result in bags with varying levels of biodegradability and environmental impact. Therefore, it is essential to look for certifications and labels like "ASTM D6400" or "EN 13432" when purchasing biodegradable plastic bags to ensure their environmental claims are legitimate.
In conclusion, the development of biodegradable plastic bags offers a promising way to reduce plastic waste and its environmental impact. Materials such as polylactic acid (PLA), starch-based plastics, and polyhydroxyalkanoates (PHA) allow for bags that degrade more quickly and safely in suitable conditions. However, it's crucial to understand that these bags require specific environments, such as industrial composting facilities, to biodegrade effectively. By choosing biodegradable plastic bags responsibly and promoting their proper disposal, we can contribute to a greener future and mitigate the harmful effects of traditional plastic bags on our planet.