Biodegradable plastic bags are designed to break down over time, primarily through the action of microorganisms.
The Microbial Breakdown Process
According to available information, like some degradable bags, biodegradable plastic bags have microorganisms added to break down the plastic. This means that the plastic material itself is formulated or treated in a way that allows bacteria, fungi, and other microbes present in certain environments to consume and metabolize the polymer structure of the bag.
This microbial activity breaks down the complex plastic polymers into simpler substances such as water, carbon dioxide, and biomass. The speed and effectiveness of this breakdown process depend heavily on the specific environmental conditions, including:
- Presence of Microorganisms: A sufficient population of the right types of microbes is necessary.
- Moisture: Water is often required for microbial activity.
- Temperature: Optimal temperatures accelerate the process.
- Oxygen: The presence or absence of oxygen (aerobic vs. anaerobic conditions) influences the types of microbes and the breakdown products.
Biodegradable vs. Compostable Bags
It's important to distinguish biodegradable bags from compostable bags, as they work differently and are designed for different disposal methods.
The reference states: "Compostable bags are made of natural plant starch, and do not produce any toxic material. Compostable bags break down readily in a composting system through microbial activity to form compost."
Here's a simple comparison:
| Feature | Biodegradable Bags | Compostable Bags |
|---|---|---|
| Material | Often still plastic, formulated to degrade | Made from natural plant starches (e.g., corn) |
| Breakdown Mech. | Microorganisms added to help break down plastic | Microbial activity breaks down plant material |
| Output | Breaks down into simpler compounds (CO2, H2O, biomass) | Breaks down to form nutrient-rich compost |
| Ideal Environ. | Requires specific conditions (depends on type) | Designed for commercial or home composting systems |
| Toxic Residue | Can potentially leave residues depending on the formulation | Generally do not produce toxic material |
While both types rely on microbial action, biodegradable bags often require specific industrial or environmental conditions to break down effectively, and the process may not result in nutrient-rich compost. Compostable bags, being plant-based, are specifically designed to decompose quickly and safely in a proper composting environment.
In summary, biodegradable plastic bags work by incorporating elements or additives that make the plastic susceptible to consumption by microorganisms under suitable conditions, leading to its eventual disintegration.
Find more information on sustainable packaging here: Learn More About Bag Disposal
