With growing awareness of environmental protection, a large number of eco-friendly, sustainable trash bags have appeared on the market, particularly biodegradable and compostable bags. Consumers can easily confuse the two concepts.
As someone who has worked at a biodegradable bag manufacturer for many years, I'd like to share a detailed explanation of the differences between compostable and biodegradable trash bags. I hope this will help you choose the right eco-friendly trash bag.
What Are Compostable Trash Bags?
Bags that meet the requirements of ASTM 6400 (Specification for Compostable Plastics) or EN 13432 (Compostable Packaging) must fully biodegrade within 90-180 days in an industrial composting environment (at approximately 60°C). They must also contain no heavy metals or toxic substances during decomposition and be able to sustain plant life.
Materials for making compostable trash bags
- PLA (polylactic acid)
- PBAT (polybutylene adipate terephthalate)
- Corn starch, sugar cane or potato starch
Two types of composting:
Compostable plastics are categorized as industrial compost and garden compost.
Industrial composting: high temperatures, controlled humidity, and microbial activity. Most compostable bags are certified to degrade in 90-180 days under these conditions.Compostable plastics on the market are generally biodegradable under industrial composting conditions.
Home composting: lower temperatures and a slower process. Only some compostable bags are certified this way.
Certifications:
- ASTM D6400 (USA)
- EN13432 (EU)
- OK Compost Home/Industrial (TÜV Austria)
- BPI Certified (Biodegradable Products Institute)
These certifications guarantee that the bag will fully break down in composting conditions, without harming the soil or environment.
What Are Biodegradable Trash Bags?
Plastic bags that can be completely digested by microorganisms for energy are broken down into water, CO2, and microorganisms.
Biodegradable plastic bags are made from:
- Biodegradable plastics: Renewable plant-based materials, such as corn, cassava, and sugarcane starch, are used to produce polylactic acid (PLA) and starch-based biodegradable plastics. Under suitable conditions, these materials are decomposed by microorganisms into water, carbon dioxide, and biomass.
- Synthetic biodegradable plastics: Chemically synthesized biodegradable polymers, such as PBAT and PBS, are mixed with PLA in a specific ratio to enhance the bag's flexibility and degradation properties.
Decomposition Rate and Conditions:
Degradation rates are affected by ambient temperature, humidity, microorganisms, and oxygen levels.
- Degradation in natural environments (such as soil, air, and water) is slow, potentially taking months to years.
- In industrial composting environments, with high temperatures (approximately 55-60°C), suitable humidity, and active microorganisms, PLA and PBAT materials can completely decompose in approximately 90 days, converting into harmless water and carbon dioxide.
- In landfills or oxygen-deficient environments, the degradation process is significantly slowed, and complete decomposition may not occur. Some materials may also produce greenhouse gases such as methane.
Compostable vs Biodegradable Trash Bags: Key Differences
| Comparison Point | Compostable Trash Bags | Biodegradable Trash Bags |
|---|---|---|
| Material Source | 100% plant-based materials (e.g. corn starch, PLA, other biopolymers) | Plant-based or synthetic degradable polymers, often blended with conventional plastics (e.g. PBAT, PBS, small amount of PE) |
| Degradation Conditions & Time | Fully decomposes within 90–180 days under industrial/home composting conditions | Degrades in 3–24 months under specific conditions (temperature, humidity, microbes); very slow in landfills or natural environments |
| Eco-Friendliness of End Products | Breaks down into water, CO₂, and biomass; no toxic residue | Some fully mineralize, others may leave microplastics and potentially harm the ecosystem |
| Certification Standards | Clearly defined (e.g. BPI, EN13432, ASTM D6400, OK Compost) | Standards vary; some may have EN13432/ASTM D6400, others have no valid certification and only claim “biodegradable” |
| Common Use Cases | Kitchen scraps, organic waste disposal, municipal composting, eco-friendly households | General household and office trash, temporary plastic alternatives, non-strict degradation use cases |
| Cost & Market Availability | Higher cost than regular plastic bags; increasing availability supported by policy | Generally cheaper than compostable bags; wide market availability but inconsistent quality |
Decomposition Mechanisms: Biodegradable Vs Compostable Plastic Bags
The compostability of compostable garbage bags depends on the temperature, humidity, and microbial activity of the composting environment. Decomposed materials can be converted into organic fertilizer, improving soil resources.
Biodegradable garbage bags gradually degrade through the scission of natural or synthetic polymer chains and the action of microorganisms. Bio-based materials are fully degradable, while plastic-containing products often only partially degrade, leaving behind microplastic residues.
Performance in Composting Environments
Compostable garbage bags typically decompose completely within 90 days in industrial composting plants (55-60°C), leaving no plastic residue. Home composting facilities may take longer.
Biodegradable garbage bags: Polymers such as PLA, PBAT, and PBS can degrade by over 90% in three to six months under ideal industrial composting conditions. However, degradation rates are significantly lower in soil or natural composting conditions, potentially requiring more than a year.
Differences in Degradation in Landfills and Natural Environments
Compostable garbage bags degrade very slowly in landfills due to the lack of oxygen and low temperatures. They may take years to decompose and may even produce greenhouse gases such as methane.
Biodegradable bags are less likely to degrade in ordinary landfills or natural environments, and some materials will only physically break down, leaving microplastics remaining in the environment for a long time, causing secondary pollution.
Actual Impact on Ecology and Soil
Compostable garbage bags, after decomposition, can help improve soil and serve as natural, green waste for plants.
Biodegradable garbage bags are made of high-purity bio-based materials, their impact on soil is relatively minimal. However, if they are adulterated with other ingredients or if they do not degrade completely, microplastics can enter the soil and be absorbed by plants, damaging the ecosystem.
How to Deal with Compostable Bags Vs Plastic Bags
Handling Compostable Bags:
Proper Composting:
Industrial compostable bags require professional facilities (around 60°C, aerobic conditions).
Home compostable bags can break down in backyard compost heaps, ensuring moisture and aeration.
Risks of Mishandling:
If discarded in regular trash, they may not decompose, behaving like plastic bags.
Should not be mixed with plastic recycling, as they contaminate the stream.
Handling Plastic Bags:
Reduce Usage:
Use reusable bags whenever possible to avoid unnecessary single-use plastic bags.
Recycle:
Drop clean plastic bags at designated recycling points, like supermarket bins.
Reuse:
Reuse plastic bags (e.g., as trash liners or storage) before disposal.
How to Choose the Right Garbage Bag?
When choosing compostable or biodegradable trash bags, it's crucial to identify reputable certification marks. These marks indicate that the product has passed rigorous environmental testing and demonstrates true, effective compostability.
BPI Certification
BPI is a leading compost certification organization in North America. Certification based on ASTM D6400 or D6868 ensures that products can be completely decomposed and harmlessly converted within a specified timeframe (usually approximately 90 days) under industrial composting conditions. Trash bags bearing the BPI mark are reliably compostable.
OK Compost Certification
The European EN 13432 standard is divided into two categories: "OK Compost Industrial" and "OK Compost Home," intended for use in industrial composting plants and home composting environments, respectively. Products certified with the OK Compost certification are biodegradable and non-toxic in composting environments.
EN 13432 Standard
This is the key European standard for assessing the suitability of packaging for composting and biodegradation. Products that meet this standard must meet multiple requirements including biodegradability, disintegration, ecotoxicity and heavy metal restrictions, indicating that the product can be safely and completely decomposed under industrial composting conditions.
Common Pitfalls and Anti-Counterfeiting Tips
Beware of "Semi-degradable" or Uncertified Products
Some products marketed as "biodegradable" actually only contain small amounts of bio-based materials or additives, making the core plastic difficult to degrade and lingering in the environment. When choosing, be sure to check for authoritative certification marks.
Authenticity of Certification Marks
There are counterfeit certifications or misused logos on the market. Verify the product's certification status on the certification agency's official website or choose a reputable brand.
Understand the Suitable Degradation Environment
Before purchasing, confirm the product's suitable degradation environment (home composting, industrial composting, or natural environment). For example, bags certified only for industrial composting may not decompose effectively in home composting conditions.
Check Product Details
Pay attention to product specifications such as material composition, thickness, and durability. Poor-quality products may degrade quickly but lack durability, affecting the user experience.
Authoritatively Certified Compostable and Biodegradable Garbage Bag Brand
| Brand Name | Certifications | Material Features | User Feedback & Highlights |
|---|---|---|---|
| BioBag | BPI, OK Compost HOME / INDUSTRIAL | 100% plant-based; suitable for home and industrial composting | Easy to store, medium thickness, durable, high customer satisfaction |
| Glad Compostable | BPI certified | PLA composite; ideal for food waste disposal | Sturdy for household use, good odor control |
| If You Care | BPI certified, EN 13432 | Biodegradable, chlorine-free, unbleached | Uses eco-friendly paper packaging; praised for sustainability values and quality |
| EcoSafe | OK Compost INDUSTRIAL, EN 13432 | Bio-based with partial synthetic materials; balanced performance | Popular in commercial use, strong load-bearing capacity, good value for money |
Conclusion
Biodegradable and compostable trash bags are not the same. Compostable bags are designed to break down completely and safely in composting environments, leaving behind nutrient-rich soil. Biodegradable bags, on the other hand, are often unregulated and can leave behind harmful microplastics.
If you're looking to make a truly eco-friendly switch, certified compostable trash bags are the way to go. They're better for the planet, better for the soil, and better for your conscience.Looking for bulk compostable trash bags for your business?
Want to switch to certified compostable trash bags? At Orizon Biomaterials, we specialize in BPI and EN13432 certified compostable solutions for households, businesses, and brands.
Explore Our Compostable Trash Bags ➜
FAQ
What’s the difference between compostable and biodegradable trash bags?
Compostable bags break down into safe compost under set conditions; biodegradable bags degrade over time, often leaving residues.
Can compostable bags go in the regular trash?
They can, but they won't compost in landfills. Best to use in composting systems.
Are biodegradable trash bags actually eco-friendly?
Not always. They often break into microplastics without full decomposition.
Are compostable bags better for the environment?
Yes—when properly composted, they leave no harmful residue and reduce plastic pollution.
Source:
- Wikipedia https://en.wikipedia.org/wiki/Biodegradable_bag
- Amscompostableusa https://amscompostableusa.com/blog/how-compostable-bags-are-made
- Burnside https://www.burnside.sa.gov.au/files/assets/public/v/1/environment-amp-sustainability/waste-recycling-amp-composting/what-goes-in-which-bin/compostable-degradable-and-biodegradable-bags-fact-sheet.pdf
