EN ISO 17556:2019 PDF

Overview

EN ISO 17556:2019 - Plastics: Determination of the ultimate aerobic biodegradability of plastic materials in soil - specifies a laboratory method to quantify how completely plastic materials biodegrade in soil under aerobic conditions. The method measures either oxygen demand in a closed respirometer or the amount of carbon dioxide (CO2) evolved. Test soil humidity is adjusted to encourage an optimum degree of biodegradation. The standard applies to natural and synthetic polymers, copolymers, mixtures, plastics with additives (plasticizers, colorants) and water‑soluble polymers.

Key topics and technical requirements

• Test principle: Biodegradation assessed by measuring O2 consumption (respirometry) or CO2 evolution over time to calculate percentage biodegradation.
• Test soils / inoculum: Use of non‑adapted soil simulates natural conditions; pre‑exposed (adapted) soil can be used to assess biodegradation potential.
• Soil preparation: Collection, sieving, standard soil options, measurement of soil characteristics (pH, organic carbon) and humidity/pH adjustment to optimize microbial activity.
• Materials and scope: Applies to polymers, polymer blends, additives and water‑soluble polymers; excludes materials that inhibit microbial activity unless alternative test setups or concentrations are used.
• Controls and inhibition: Inclusion of inhibition controls or alternative methods when test materials affect soil microorganisms.
• Apparatus and procedure: Requirements for respirometers and CO2 measurement systems, sample preparation, test duration (revised maximum test period up to two years) and recommended replicates (corrected to three).
• Calculations & reporting: Methods to convert O2/CO2 data to percent biodegradation; formula updates are included in this edition. Annexes cover ThOD (theoretical oxygen demand), respirometer principles, CO2 systems, and interlaboratory examples.
• Safety: Precautions for handling soil due to potential pathogens.

Practical applications

• Product testing for biodegradable plastics intended for agricultural mulch, horticulture (twine, pots, clips), disposable items used on/into soil, and water‑soluble polymer products.
• Development and R&D: formulation screening and optimization to improve soil biodegradability.
• Conformity assessment and claims substantiation for environmental labeling, regulatory compliance or end‑of‑life performance.
• Environmental and contract testing laboratories implementing standardized soil biodegradation tests.

Who uses this standard

• Polymer and plastic manufacturers, compounders and additive suppliers
• Accredited testing laboratories and research institutions
• Regulatory agencies and certification bodies assessing biodegradability claims
• Agricultural product developers and waste management stakeholders

Related standards and references

• Normative references cited: ISO 10390 (soil pH) and ISO 10694 (soil organic/total carbon). Annexes in EN ISO 17556:2019 provide practical measurement system examples, ThOD calculations, and long‑term/interlaboratory guidance.

Keywords: EN ISO 17556:2019, plastics biodegradability, aerobic biodegradability, soil biodegradation test, respirometer, CO2 evolved, oxygen demand, test soil, inhibition control.