ISO 14855-1:2012

Overview

ISO 14855-1:2012 defines a laboratory method to determine the ultimate aerobic biodegradability of plastic materials under controlled composting conditions. The standard measures biodegradation primarily by analysis of the carbon dioxide (CO2) evolved during composting and by assessing the degree of disintegration (and optionally mass loss) of the test material at the end of the test. It simulates intensive aerobic composting representative of the organic fraction of municipal solid waste using a compost-derived inoculum under closely controlled temperature, aeration and humidity.

Key technical topics and requirements

• Test principle: Solid-phase respirometric system that quantifies cumulative CO2 evolved from the test material and blanks; percentage biodegradation is calculated versus the theoretical CO2 (derived from measured total organic carbon, TOC).
• Inoculum and bed options: Mature compost as the default inoculum/bed; a validated activated vermiculite (mineral bed) variant is provided to reduce priming effects and facilitate full carbon balances, biomass analysis and residue recovery.
• Controlled environment: Incubation typically at 58 °C ± 2 °C (or justified alternative temperature) in the dark or diffused light; aeration and moisture are monitored and maintained. Test duration is limited (not exceeding six months).
• Measurements and outputs: Cumulative CO2 evolution (continuous or periodic), percentage conversion of carbon to CO2, biodegradation rate, lag/biodegradation/plateau phases, degree of disintegration and optional mass loss.
• Quality and reporting: Requirements for positive controls (TLC-grade cellulose), blanks, calculation methods (theoretical CO2, % biodegradation), and test-report content. The standard includes informative annexes with example graphs, mass-loss procedures and round-robin testing guidance.

Practical applications and who uses the standard

ISO 14855-1 is used by:

• Plastics manufacturers and compounders to validate compostability claims and compare formulations.
• Testing laboratories for standardized biodegradation testing and certification preparation.
• Product developers and R&D teams to screen materials and optimize formulations for compostable applications.