 (1).jpg "Compostable Plastics vs. Oxo-Biodegradable Plastics: Key Differences, Pros and Cons, and British Standards")
Compostable Plastics vs. Oxo-Biodegradable Plastics: Key Differences, Pros and Cons, and British Standards
Compostable Plastics vs. Oxo-Biodegradable Plastics: Key Differences, Pros and Cons, and British Standards
As global awareness of environmental issues rises, businesses and consumers are increasingly seeking sustainable alternatives to traditional plastics. Two popular alternatives are compostable plastics and oxo-biodegradable plastics. While both claim to reduce the environmental impact of plastic waste, they function in different ways and have distinct advantages and disadvantages. This document provides an overview of the key differences, how each type works, and their relation to British Standards. To see our full range of Compostable, Oxo-biodegradable products Click Here...
Compostable Plastics
Definition: Compostable plastics are designed to break down into natural elements, such as water, carbon dioxide, and biomass, under specific conditions (typically in industrial composting environments). These materials leave no toxic residues behind and are often derived from renewable resources like corn starch, sugarcane, or potato starch.
How Compostable Plastics Work:
When exposed to the correct conditions of heat, moisture, and microbial activity (typically found in industrial composting facilities), compostable plastics break down into non-toxic materials within a specified period, usually 6–12 weeks.
British Standards:
In the UK, compostable plastics must adhere to BS EN 13432, the standard for compostability. According to this standard, plastics labeled as compostable must break down within 12 weeks and leave no more than 10% residue after six months. This standard ensures that compostable plastics will not harm soil or compost quality.
Key Points:
- Derived from: Plant-based materials (bioplastics) or a combination of plant and petroleum-based materials.
- Degradation Process: Breaks down into water, carbon dioxide, and biomass in controlled composting environments.
- End Result: No toxic residues, fully integrated into compost.
Pros of Compostable Plastics:
- Environmentally friendly: They break down into organic matter, enriching the soil and leaving no toxic substances.
- Reduces waste in landfills: Compostable plastics help divert waste from landfills and incinerators.
- Fossil-fuel reduction: They are often made from renewable resources, reducing dependence on petroleum-based plastics.
- Meets strict standards: Compostable plastics meet recognized standards like BS EN 13432, ensuring safe breakdown.
Cons of Compostable Plastics:
- Composting requirements: They need specific industrial composting conditions (temperature, humidity, and microbes) that may not be available in every region.
- Cannot degrade in landfills: Without access to oxygen and the right conditions, compostable plastics do not break down properly in landfills.
- Misleading disposal: If compostable plastics end up in regular plastic recycling streams, they can contaminate the recycling process.
- Higher costs: Often more expensive to produce than traditional plastics or oxo-biodegradable options.
Oxo-Biodegradable Plastics
Definition: Oxo-biodegradable plastics (often petroleum-based) are designed to degrade through oxidation, breaking down into smaller fragments when exposed to oxygen, UV light, and heat. This degradation process can eventually lead to biodegradation by microorganisms.
How Oxo-Biodegradable Plastics Work:
Oxo-biodegradable plastics are made by adding specific chemicals (pro-oxidant additives) to traditional plastics. When exposed to UV light or heat, these additives trigger a degradation process, fragmenting the plastic into smaller pieces. Over time, microorganisms can digest these fragments, resulting in their biodegradation into water, carbon dioxide, and biomass.
British Standards:
The UK does not have a specific British Standard for oxo-biodegradable plastics, but they are generally tested under ASTM D6954 or BS 8472 for oxo-biodegradability, which measure the degradation process under specific environmental conditions. However, the environmental claims made by oxo-biodegradable plastics are sometimes debated due to concerns over microplastics.
Key Points:
- Derived from: Petroleum-based plastics with added pro-oxidant additives.
- Degradation Process: Breaks down through oxidation into smaller fragments, which are further degraded by microorganisms.
- End Result: Smaller plastic fragments eventually degraded into carbon dioxide, water, and biomass.
Pros of Oxo-Biodegradable Plastics:
- Degrades faster: They begin to degrade much faster than traditional plastics when exposed to environmental factors like sunlight and heat.
- Affordable: Often less expensive to produce than compostable plastics.
- Compatible with traditional plastic manufacturing: Can be used with existing plastic infrastructure and equipment.
- Works in diverse environments: Can degrade in various environments, including landfills, though at varying rates.
Cons of Oxo-Biodegradable Plastics:
- Microplastic risk: If degradation is incomplete, it can leave behind microplastics, which pose a long-term environmental threat.
- Debate over biodegradability: There is ongoing debate about whether oxo-biodegradable plastics fully biodegrade or just break into small, persistent fragments.
- No UK compostability standard: They do not meet the compostability standards set by BS EN 13432, meaning they cannot be processed in industrial composting facilities.
- Not truly circular: Although oxo-biodegradable plastics degrade, they don’t contribute to soil enrichment like compostable plastics do.
Compostable vs. Oxo-Biodegradable Plastics: Key Differences
| Feature | Compostable Plastics | Oxo-Biodegradable Plastics |
|---|---|---|
| Material Source | Typically plant-based | Petroleum-based with additives |
| Degradation Process | Microbial breakdown in controlled composting | Oxidative degradation followed by microbial action |
| End Result | Water, CO2, and biomass | Smaller plastic fragments, CO2, and biomass |
| British Standards | BS EN 13432 (Compostability) | ASTM D6954 or BS 8472 (Oxo-biodegradability) |
| Environmental Impact | Leaves no toxic residue, enriches soil | May leave microplastic residues if not fully degraded |
| Decomposition Conditions | Requires industrial composting (heat, moisture) | Requires oxygen, UV, heat, and microbial presence |
Conclusion:
Both compostable and oxo-biodegradable plastics offer potential solutions to plastic pollution, but their environmental benefits and limitations depend on the disposal and degradation conditions.
Compostable plastics are ideal for situations where controlled composting facilities are available, offering a cleaner end result with no toxic residues. Oxo-biodegradable plastics may degrade faster in various environments, but concerns over microplastics persist. When choosing between these two options, businesses and consumers should consider the available disposal infrastructure, cost implications, and long-term environmental impact. Additionally, adherence to British Standards, such as BS EN 13432 for compostable plastics, ensures clarity on the biodegradability claims and the real-world sustainability of the materials.
