compostability

Compostability is the property of a material to break down in a composting process into carbon dioxide, water, inorganic compounds, and biomass within a defined timeframe, leaving no toxic residues and yielding a usable soil amendment. Compostable materials are designed to contribute to organic-waste diversion, but compostability is not universal: some items may biodegrade in certain environments but not in a home or industrial composting facility; and recyclability follows a different path.

Standards and certifications: Industry standards define what qualifies as compostable. In Europe, EN 13432 specifies criteria for packaging to be recovered by industrial composting or anaerobic digestion. EN 14995 covers certification of compostable plastics and textiles. In the United States, ASTM D6400 and D6868 address compostability of plastics and molded products. Independent certification marks, such as OK compost INDUSTRIAL and OK compost HOME (TÜV Austria), BPI Compostable, and DIN CERTCO, indicate conformity to these standards. Certifications typically require disintegration and guideline for non-toxic residue and the compostability timeframe.

Practical considerations: Not all compostable products behave the same in all settings. Home composting conditions vary; many items labeled compostable require industrial facilities capable of maintaining high temperatures and specific moisture. Contamination of compost streams by non-compostable plastics or coatings can disrupt the process. Local programs determine whether compostable products are accepted and how to separate them.

Environmental impact: When properly processed, composting can reduce landfill volumes and return nutrients to soil. However, life-cycle benefits depend on production, transport, and end-use. Some so‑called compostable plastics may fragment rather than fully degrade in home piles, and may require specialized facilities to avoid microplastic release or toxic residues.