Overview
ISO 14239:2017 - Soil quality - Laboratory incubation systems for measuring the mineralization of organic chemicals in soil under aerobic conditions - specifies laboratory incubation systems and general requirements for measuring the rate and extent of mineralization of organic compounds in soil by monitoring carbon dioxide (CO2) evolution. The standard covers six validated incubation systems applicable to both soluble and insoluble compounds and is intended for aerobic mineralization studies (not for material-balance studies, which are often test-substance specific).
Key topics and technical requirements
- Six accepted incubation systems: flow-through system, soda-lime column system, biometer system, radiorespirometer, microradiorespirometer, and miniaturized respirometer.
- Measurement principle: quantification of mineralization by CO2 evolution; radiolabelled (14C) compounds provide the most reliable mineralization data.
- General incubation conditions (default unless justified otherwise):
- Temperature: 20 ± 2 °C
- Soil pore water pressure: −0.01 MPa to −0.03 MPa (or 40–60% of maximum water-holding capacity)
- Incubation: in the dark
- Soil and test material characterization: soils must be collected and handled per ISO 18400-206 and characterized per ISO 11266; test materials should also be characterized per ISO 11266.
- Quality checks: recoveries of CO2 can be validated using known quantities of CaCO3 (including 14C-labelled) with acid dissolution to confirm system recovery.
- Advantages and limitations: the standard describes trade-offs for each system (e.g., flow-through systems suit volatile compounds but are leak-sensitive; soda-lime columns allow free oxygen access but require CO2 recovery steps; biometers are space-efficient but less suitable for long-term incubation).
Practical applications and users
ISO 14239:2017 is used to generate reproducible mineralization data for regulatory dossiers, environmental fate studies, and research into biodegradation of pesticides, industrial chemicals, and other organic compounds in soil. Typical users include:
- Environmental chemists and soil scientists
- Analytical and environmental testing laboratories
- Regulatory agencies and risk assessors
- Agrochemical and chemical manufacturers conducting fate and biodegradation studies
- Academic researchers studying microbial degradation and soil biogeochemistry
Related standards and notes
- Normative references include ISO 11266 (biodegradation guidance), ISO 18400-206 (soil sampling), ISO 11274, and ISO 11269-2.
- The second edition (2017) updated the original (1997) and added two additional incubation system options.
- Warning: methods may use hazardous materials; follow national safety and waste regulations.
Keywords: ISO 14239:2017, soil quality, mineralization, aerobic conditions, CO2 evolution, laboratory incubation systems, biodegradation in soil, radiolabelled compounds.