SIST EN ISO 19679:2020 PDF

Overview

EN ISO 19679:2020 specifies a laboratory test method for measuring the aerobic biodegradation of non‑floating plastic materials settled at a seawater/sediment interface (marine sandy sediment). The method quantifies biodegradation by analysing evolved carbon dioxide (CO2) produced during microbial oxidation of the material. It simulates benthic/sub‑littoral habitats under controlled conditions and can be applied to other solid materials, but not to materials buried deeper in marine sediment.

Key topics and requirements

• Test principle: Biodegradation is determined by measuring cumulative CO2 evolved from test specimens and comparing it to the theoretical amount of CO2 (ThCO2) calculated from the material’s carbon content (TOC).
• Test environment: Laboratory simulation of the seawater–seafloor interface (photic sublittoral conditions) using marine sandy sediment and overlying seawater.
• Materials covered: Non‑floating plastics and other solid materials that settle at the seawater/sediment interface. Tests for buried (deep sediment) biodegradation are outside the scope.
• Measurement methods: Primary method is CO2 respirometry (evolved CO2 analysis); oxygen consumption monitoring is noted as an alternative approach (see ISO 18830).
• Test elements (documented in the standard): preparation of sediment, reagents and apparatus, specimen pre‑conditioning, test setup and run, CO2 monitoring, calculation of biodegradation percentage, visual inspection, validity criteria and test reporting.
• Calculations and reporting: Procedures for converting CO2 data to percentage biodegradation based on TOC/ThCO2, plus guidance on expressing and interpreting results.
• Limitations: Standard emphasizes that laboratory conditions do not always represent optimum biodegradation conditions in nature.

Applications and users

• Manufacturers and formulators of biodegradable plastics who need to evaluate marine biodegradation behaviour for product development or environmental claims.
• Environmental laboratories and testing services performing standardized marine biodegradation assessments.
• Regulatory bodies, ecotoxicologists and researchers assessing fate of plastics in coastal and benthic environments.
• Product stewardship and sustainability teams assessing end‑of‑life behavior for items that may sink (e.g., fishing gear).

Practical value: provides a reproducible, quantitative method to compare materials, support environmental risk assessments, and substantiate biodegradation claims for materials that tend to settle on the seafloor.

Related standards

• ISO 18830 - Measurement of aerobic biodegradation by oxygen consumption (alternative/respirometric approach).
• Annex A of ISO 19679 offers an example of a respirometric system based on CO2 measurement and calculation guidance (informative).