Understanding the Difference Between Biodegradable and Compostable Items

The terms biodegradable and compostable are often used interchangeably, but there are key differences between them. Understanding these differences can help consumers make more informed decisions about the products they use and dispose of, ultimately contributing to more sustainable waste management practices.

Key Differences Between Biodegradable and Compostable Items

Differentiating between biodegradable and compostable items is crucial for understanding their environmental impact and proper disposal. Compostable items have specific certifications and characteristics, while biodegradable items may not meet the same standards.

Certifications

Certifications such as the BPI (Biodegradable Products Institute) logo and standards are crucial for identifying compostable items. These certifications ensure that the product has undergone rigorous testing to meet strict standards for compostability. On the other hand, biodegradable items do not necessarily have such certifications, which means their decomposability may vary widely depending on the product.

Material Composition

Compostable materials are typically made from organic matter such as plant-based polymers, like PLA derived from corn starch, or other natural materials such as paper or wood pulp. These materials are designed to break down into non-toxic components in composting conditions. Biodegradable items, however, can be made from various materials, including plastic and synthetic polymers, which may not decompose completely into non-toxic residues.

Decomposition Process

Compostable items specifically refer to materials that can be broken down into compost, a nutrient-rich soil amendment. This process is managed in a controlled environment, ensuring that no toxic residues are left behind. In contrast, biodegradable items simply refer to materials that can be broken down by microorganisms over time. This does not guarantee that the end products are environmentally friendly or beneficial.

Specific Material Considerations

Some biodegradable materials, particularly those made from polyethylene (PE), may continue to have a negative impact on the environment. PE typically takes a very long time to decompose and can leach harmful residues into the surrounding environment. Therefore, extra care should be taken with products made from PE.

Testing and Certification for Compostability

Ensuring that an item is truly compostable involves a lengthy and costly certification process. The BPI website provides all the necessary information on compostability, and certifications involve several steps:

The product must show it will break down into carbon dioxide (CO2) during a controlled lab composting process. Only a few labs in the world are certified to perform these tests, which include analysis for disintegration, metals, plant toxicity, and chemical content. The entire product, including glue, coloring, and other components, must pass the testing process. The product is added to a specific mix and subjected to controlled temperatures and air flow, with the exit air passing through a CO2 capture system, which measures the CO2 output.

The entire process is done in triplicate to ensure accuracy and reliability.

Conclusion

Understanding the difference between biodegradable and compostable items is crucial for promoting more sustainable waste management practices. Compostable items are specifically designed to break down into non-toxic compost, while biodegradable items may not meet the same standards. Consumers should look for certifications like those provided by the BPI to ensure the products they use and dispose of are truly environmentally friendly.