A certified compostable bag is designed to break down under a specific set of conditions — and those conditions are the reason industrial composting facilities matter. A backyard pile rarely sustains the heat, moisture, and microbial activity that a commercial facility controls, which is why a product certified to ASTM D6400 or EN 13432 is certified for industrial composting, not for every disposal route.
The process begins at intake. Facilities screen incoming material and confirm it belongs in the organics stream; buyers and waste managers should always check with their local facility about which items it accepts, since acceptance varies by community. Accepted material is typically shredded to increase surface area, then placed in windrows or enclosed vessels where temperature, moisture, and oxygen are managed.
Next comes the active phase. Microbial activity heats the pile into its thermophilic stage, roughly 55 to 65 degrees Celsius, where heat and moisture drive hydrolysis and microbial enzymes break polymer chains into smaller molecules. Microorganisms then metabolize that carbon into carbon dioxide, water, and biomass. This is the distinction behind certification: a certified compostable product must both disintegrate and biodegrade, and pass an ecotoxicity test on the finished compost — physical breakup alone is not enough. Under industrial composting conditions, certified products must reach at least 90% disintegration within 12 weeks.
Finally, the material cures. Microbial activity slows, temperatures fall, and the compost matures and stabilizes before screening removes any remaining contaminants. What leaves the facility is finished compost for soil use — the end of a cycle that starts with a bag and ends, under the right conditions, as a soil amendment rather than landfill waste.
Disclaimer: Product descriptions, specifications, and certification references in this article are provided for general information. Compostability claims (including ASTM D6400, EN 13432, and GB/T 19277) refer to industrial composting conditions; commercial composting facilities may not be available in all communities. Certifications apply only to the specific products listed in the relevant certificates. For current certification documentation, contact Greenstar@greenstarmaterial.com.