The core environmental indicators for biodegradable bags include biodegradability (≥90%), ecotoxicity (degradation products must pass plant growth safety tests), bio-based content (reflecting the proportion of renewable raw materials), carbon footprint (measuring greenhouse gas emissions throughout the product’s life cycle), disintegration rate (ensuring complete physical decomposition), and international authoritative certifications (such as ASTM D6400 and EN 13432). These scientific indicators collectively verify the product’s true environmental performance.
I. Biodegradability: A Quantitative Standard for Core Performance
Biodegradability refers to the percentage of a material that is decomposed by microorganisms under specific environmental conditions. International standards (such as ASTM D6400) require a biodegradability of over 90% within 180 days.
This indicator directly reflects whether the product can completely “disappear,” avoiding microplastic residues. When purchasing, it is essential to check third-party laboratory reports to ensure the data is authentic and reliable; this is the primary basis for measuring environmental effectiveness.
1. Definition and Testing Methods
Biodegradability refers to the percentage of a material that is decomposed into carbon dioxide, water, and biomass by microorganisms under specific environmental conditions. Internationally accepted testing standards include:
(1) ASTM D6400: requires a biodegradability rate of over 90% within 180 days
(2) EN 13432: specifies a biodegradability rate of not less than 90% within 6 months
(3) ISO 14855: a standardized testing method using a laboratory-simulated composting environment
2. Common Misconceptions about Biodegradation
(1) A 100% biodegradability rate is unrealistic: over 90% is considered complete degradation
(2) Degradation curves differ significantly between different materials: time is equally important
(3) Laboratory data needs to be comprehensively evaluated in conjunction with the actual application environment
II. Degradation Time: A Key Parameter for Process Controllability
Degradation time is an important parameter measuring the time required for a biodegradable bag to complete decomposition in a specific environment. Typically, under industrial composting conditions, over 90% decomposition must be achieved within 180 days, while household composting requires 6-24 months.
This indicator directly affects the compatibility between the product and the treatment facility; selection must be based on the actual conditions of the local waste treatment system to ensure that environmental commitments are effectively implemented. 
1. Standard Time Frame
Depending on the usage scenario and processing conditions, the degradation time of biodegradable bags is divided into:
(1) Industrial composting environment: Usually requires the main degradation process to be completed within 180 days
(2) Home composting environment: The standard is relaxed to 12-24 months
(3) Natural environment: The time span is large and is usually not used as a certification basis
2. Analysis of Influencing Factors
(1) Material thickness: For every 0.01mm increase, the degradation time may be extended by 20-30%
(2) Ambient temperature: The optimal temperature is 55-60℃, and the degradation time doubles for every 10℃ decrease in temperature.
(3) Microbial activity: Optimization of microbial strains in professional composting facilities can accelerate degradation by 30%-50%.
3. Practical guidance value
(1) Select products with appropriate time indicators based on local waste treatment facility conditions.
(2) Excessive degradation may affect the user experience; a balance between practicality and environmental friendliness is necessary.
(3) Companies that clearly label degradation time usually have stronger technical control capabilities.
III. Ecotoxicity: A guarantee of safe return to nature.
Ecotoxicity is the core safety indicator of the environmental performance of biodegradable bags, ensuring that decomposition products do not harm soil, water sources, or organisms. International certifications require rigorous testing, including plant growth impact assessment and heavy metal content detection, to confirm that degradation residues are non-toxic and harmless.
1. Testing Content and Standards
Ecotoxicity assessment mainly tests the potential environmental hazards of degradation products:
(1) Plant growth test: Cultivate plants such as water celery and oats using compost products. The germination rate and biomass must reach more than 90% of the control group.
(2) Earthworm acute toxicity test: Assess the impact on soil organisms.
(3) Heavy metal content test: Lead, cadmium, mercury and other 8 heavy metals must be below the limit standard.
2. Safety threshold requirements
EU EN 13432 standard stipulates that all toxicity indicators must meet the standard. US ASTM D6400 has stricter restrictions on heavy metals. High-quality products should provide third-party toxicity test reports.
3. Consumer concerns
Truly environmentally friendly products must be “harmlessly degraded”.
Avoid using degradation products with added heavy metal catalysts. Pay attention to whether the product has passed internationally recognized eco-safety certification.
IV. Carbon Footprint: Climate Impact Throughout the Life Cycle
Carbon footprint measures the greenhouse gas emissions of a product throughout its entire life cycle, from raw material acquisition, production, transportation to final disposal. It is measured in carbon dioxide equivalent (CO₂e). The lower the value, the smaller the climate impact.
When choosing biodegradable bags, pay attention to their full life-cycle carbon footprint data, and prioritize products made from renewable raw materials and clean energy to achieve true low-carbon and environmentally friendly practices.
1. Scope and Method of Calculation
Carbon footprint covers the entire process from raw material planting/mining, production and processing, transportation, use to disposal:
(1) Raw material stage: Bio-based materials typically have a carbon footprint 30%-70% lower than petroleum-based materials
(2) Production stage: Energy consumption control and process optimization can reduce emissions by 20%-40%
(3) Transportation stage: Localized production and optimized logistics can reduce impact by 10%-25%
2. Data Reference Standards
(1) Ordinary PE plastic bags: Carbon footprint approximately 1.8 kg CO₂e/kg
(2) PLA biodegradable bags: Carbon footprint approximately 0.6-1.2 kg CO₂e/kg
(3) High-quality biodegradable bags: Should be less than 1.0 kg CO₂e/kg
3. Environmental Value Selection
(1) Choose products that provide carbon footprint labels or statements
(2) Prioritize brands that use renewable energy for production
(3) Consider the weight of transportation distance on the overall environmental impact
V. Raw Material Sustainability: The Fundamental Guarantee of Environmental Protection at the Source
True environmental protection begins with raw materials. High-quality biodegradable bags must clearly label their bio-based content (typically 50%-100%), prioritize the use of non-GMO crops or agricultural byproducts, and ensure that the raw material cultivation process complies with sustainable agriculture standards (such as no deforestation and water-saving management). Choose products with authoritative certifications such as USDA BioPreferred to reduce your ecological footprint from the source.
1. Renewable Raw Material Ratio
(1) Bio-based Content: High-quality products should clearly indicate the proportion of plant-based raw materials (usually 50%-100%)
(2) Raw Material Source: Non-GMO crops, sustainable agriculture certification, and no competition with food crops for land
(3) Fossil-based Ratio: Petroleum-based raw materials should come from industrial by-products rather than primary extraction
2. Certification System Reference
(1) USDA BioPreferred: USDA Bio-based Product Certification
(2) OK biobased: Belgian third-party bio-based content certification
(3) FSC/PEFC: Forest Sustainable Management Certification (e.g., using wood-based raw materials)
3. Procurement Decision Recommendations
(1) Require suppliers to provide raw material traceability information
(2) Prioritize brands with transparent supply chains
(3) A higher bio-based ratio is not necessarily better; performance requirements must also be considered.
