In today's environmentally conscious world, the term "degradable" has become increasingly prominent when discussing eco-friendly products. However, the true definition and specifications of degradable materials can often be misunderstood. As consumers, it's crucial to have a clear understanding of what degradability means and how it differs from other sustainability buzzwords like "biodegradable" and "compostable."
What is Degradable?
The term "degradable" refers to the ability of a material to break down and decompose over time, typically under the influence of natural environmental factors such as sunlight, oxygen, or microorganisms. This process of degradation can lead to the material's physical and chemical breakdown, ultimately reducing it to its basic components.
It's important to note that the term "degradable" is a broad one and does not necessarily imply that the material will break down completely or in a specific timeframe. The rate and extent of degradation can vary depending on the material's composition and the environmental conditions it is exposed to.
Specifications for Degradable Materials
To ensure consistency and clarity, various organisations have developed standards and specifications for degradable materials. Some of the key standards include:
ASTM D5988 Standard
The ASTM D5988 standard, developed by the American Society for Testing and Materials (ASTM), outlines the test methods and requirements for determining the aerobic biodegradation of plastic materials in soil.
EN 13432 European Standard
The EN 13432 standard, established by the European Committee for Standardisation (CEN), specifies the requirements for packaging recoverable through composting and biodegradation, including the degradability of the material.
ISO 17556 International Standard
The ISO 17556 standard, developed by the International Organisation for Standardisation (ISO), provides a method for determining the ultimate aerobic biodegradability of plastic materials in soil by measuring the oxygen demand or the amount of carbon dioxide evolved.
These standards help ensure that degradable materials meet specific criteria and can be reliably identified by consumers and manufacturers.
Types of Degradation
Degradable materials can undergo various types of degradation, including:
Photodegradation
This type of degradation occurs when the material is exposed to UV radiation from sunlight, causing the polymer chains to break down and the material to become more brittle and fragile.
Oxidative Degradation
Oxidative degradation happens when the material reacts with oxygen, leading to the formation of new chemical bonds and the breakdown of the material's structure.
Hydrolytic Degradation
Hydrolytic degradation involves the breakdown of the material's chemical bonds due to the presence of water, which can occur in both natural and artificial environments.
The specific type of degradation that a material undergoes can depend on its composition and the environmental conditions it is exposed to.
Factors Affecting Degradability
The degradability of a material can be influenced by several factors, including:
- Environmental conditions: Temperature, humidity, UV exposure, and the presence of microorganisms can all impact the rate and extent of degradation.
- Material composition: The type and amount of polymers, additives, and other components in the material can affect its degradability.
- Time frame for degradation: Degradable materials can take varying amounts of time to break down, ranging from a few months to several years, depending on the specific conditions.
Understanding these factors is crucial for ensuring that degradable products are disposed of and managed properly to minimise their environmental impact.
Degradable vs. Biodegradable: Key Differences
It's important to distinguish between "degradable" and "biodegradable" materials. While both terms refer to the breakdown of materials, they have distinct definitions and implications.
Biodegradable materials are those that can be broken down by natural biological processes, typically involving the action of microorganisms like bacteria and fungi. These materials can be completely converted into natural substances, such as water, carbon dioxide, and biomass.
In contrast, degradable materials may not necessarily be broken down by biological processes. They can undergo physical, chemical, or a combination of degradation processes, which may not result in complete decomposition into natural substances.
The environmental impact of degradable and biodegradable materials can also differ, as incomplete degradation can lead to the formation of microplastics or other persistent pollutants.
Challenges and Limitations of Degradable Materials
While degradable materials offer an alternative to traditional non-degradable products, they are not without their challenges and limitations. Some of the key concerns include:
- Incomplete degradation: In some cases, degradable materials may not break down completely, leading to the formation of microplastics or other persistent pollutants.
- Potential for microplastic formation: The breakdown of degradable materials can sometimes result in the creation of microplastics, which can have negative impacts on the environment and marine ecosystems.
- Disposal and waste management considerations: Proper disposal and waste management are crucial for ensuring the effective degradation of these materials, as improper disposal can lead to environmental issues.
Addressing these challenges and limitations is an ongoing effort, with researchers and manufacturers working to improve the performance and environmental impact of degradable materials.
The Importance of Informed Consumer Choices
As consumers, our choices play a significant role in the success and adoption of degradable materials. By understanding the definition, specifications, and limitations of degradable products, we can make more informed decisions and support the development of truly sustainable solutions.
When selecting degradable products, it's essential to look for those that meet recognised standards and have been third-party certified. Additionally, proper disposal and waste management practices, such as recycling or composting, can help ensure the effective degradation of these materials.
The Future of Degradable Materials
The future of degradable materials holds both promise and challenges. Ongoing research and development are focused on improving the performance, reliability, and environmental impact of these materials. This includes exploring new polymer formulations, enhancing degradation mechanisms, and addressing the issue of microplastic formation.
As standards and regulations continue to evolve, the degradable materials industry will need to adapt and innovate to meet the growing demand for sustainable solutions. Collaboration between manufacturers, policymakers, and consumers will be crucial in shaping the future of this rapidly evolving field.
Conclusion
Understanding the definition and specifications of degradable materials is essential for making informed choices and supporting the development of truly sustainable products. By recognising the differences between degradable, biodegradable, and compostable materials, and being aware of the challenges and limitations, we can collectively work towards a future where eco-friendly solutions are the norm, not the exception.