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What is the Difference Between Degradable, Biodegradable and Compostable?

Feb. 29, 2020

Bio-based plastics and biodegradable plastics are new materials that are environmentally friendly and sustainable alternatives to traditional plastics that currently use petroleum as the raw material. "Degradable", "biodegradable", and "compostable" are terms often used when people talk about these materials. They are similar and different. The Biodegradable Bag Manufacturer will tell you about them. the difference.

When designing a new product, it is important to consider its ecological behavior, which is related to its final treatment. Of particular concern are those used in disposable packaging and consumer products. Designing these materials to be biodegradable and ensuring that they can eventually be properly and systematically disposed of will be environmentally friendly and ecologically friendly.

In the past, polymers were designed as materials that were not easily degraded. The challenge today is to design polymers that have the required functionality during use but decompose after use. The more important point is that the degradation products cannot be toxic and cannot exist in the environment for a long time, but can be completely digested by soil microorganisms within a certain period of time like food. To ensure that the market can accept biodegradable products, there is no doubt that these materials need to be demonstrated to be biodegradable within a few weeks in the waste management infrastructure (more precisely, these materials can be passed through processing facilities Microbial enzymes present in digestion / utilization).

However, these are not enough to clearly explain the difference between "degradable", "biodegradable" and "compostable" plastics. Further explanation will be made below.

(1) Degradable plastic

Degradable plastics include plastics that are degradable by physical and biological factors (light or heat, or microbial action). So-called aerobic degradation (that is, accelerated degradation by catalysts or activators at high temperatures) or photodegradable starch-polyethylene plastics can cause some environmental problems. These materials do not degrade as fast as compostable plastic blocks and may leave debris. These degraded hydrophobic fragments have a large surface area and may migrate to groundwater and soil, adsorbing and retaining some hydrophobic and highly toxic substances on the surface, such as PCB and DDT, making the content of toxic substances as high as 1% of the background content. Million times, enough to become a delivery system for toxic substances in the environment. Therefore, it must be ensured that the product is completely biodegradable within the very short time determined by the processing facility.

(2) Biodegradable plastic

Biodegradable plastics are those that can be completely digested by microorganisms in the processing system as food for energy (entering the food chain). A common one is the Biodegradable Bag. This complete microbial digestion / utilization determination is measured by testing whether the carbon of the test plastic can be completely converted to CO2 through the microbial process occurring in the cell.

Green Biodegradable Compostable Bag

Biodegradable Compostable Bag

(3) Compostable plastic

In addition to being biodegradable by microorganisms, to call a plastic "compostable" plastic must also meet a time requirement. For example, compostable plastic specifications, biodegradable plastic specifications for paper or other compostable media surface coatings, or compostable packaging standards state that these materials should biodegrade within 180 days in an industrialized composting environment. The industrialized composting environment means that the specified temperature is about 60°C, and microorganisms must be present. According to this definition, Green Biodegradable Compostable Bag does not leave debris in the residue for more than about 12 weeks, contains no heavy metals or toxic substances, and can sustain plant life.