Overview
EN ISO 15985:2017 (ISO 15985:2014) specifies a laboratory method to evaluate the ultimate anaerobic biodegradability of plastics under high‑solids anaerobic digestion conditions by measuring the biogas (CO2 and CH4) evolved. The method simulates typical anaerobic digestion of the organic fraction of municipal solid waste: test samples are incubated with a methanogenic inoculum (derived from digesters treating pretreated household waste) in static, non‑mixed vessels at >20% total solids. Results quantify the percentage and rate of carbon conversion from the plastic to biogas.
Key Topics and Requirements
- Test principle: Exposure of plastic test material to methanogenic inoculum and measurement of released biogas to determine mineralization (CO2 + CH4) and new biomass.
- High‑solids conditions: Test runs under static, non‑mixed conditions with more than 20% total solids, representative of anaerobic biogasification of municipal solid waste.
- Inoculum source: Methanogenic sludge from anaerobic digesters operating only on pretreated household (organic) waste.
- Measured outputs:
- Gaseous carbon (CO2 and CH4) evolved
- Percentage biodegradation of carbon in the test material
- Rate of conversion and optional loss‑in‑mass determinations
- Test lifecycle: Preparation of inoculum and test material, start‑up, incubation, termination, calculations and expression of results.
- Definitions and phases: Includes concepts such as total dry solids, volatile solids, lag phase, biodegradation phase and plateau phase.
- Documentation and validity: Criteria for test validity, required reporting elements and reference to normative methods (e.g., ISO 8245 for TOC/DOC).
Applications and Who Uses It
- Plastics manufacturers and compounders assessing anaerobic biodegradability claims for product design and end‑of‑life options.
- Waste management and anaerobic digestion operators evaluating feedstock compatibility and potential impacts on biogas yield.
- Certification bodies, regulators and standards bodies verifying biodegradability performance for labeling and compliance.
- Research labs and universities studying polymer degradation pathways under high‑solids anaerobic digestion conditions.
- Product developers designing plastics intended for biological recycling in anaerobic biogasification facilities.
Related Standards
- ISO 14855 (aerobic, high‑solids biodegradation testing) - for comparison under aerobic composting conditions
- ISO 11734 (anaerobic biodegradation in aqueous/low‑concentration conditions) - for soluble or low‑concentration substances
- ISO 8245 (TOC/DOC determination) - normative reference for carbon analyses
Keywords: EN ISO 15985:2017, ISO 15985:2014, plastics anaerobic biodegradation, high‑solids anaerobic digestion, biogas measurement, methanogenic inoculum, biodegradability testing.