SIST EN ISO 9439:2000 PDF

Overview

EN ISO 9439:2000 (ISO 9439:1999) specifies the carbon dioxide evolution test for evaluating the ultimate aerobic biodegradability of organic compounds in aqueous media. The method measures microbially produced CO2 from a test substance (expressed versus the theoretical CO2, ThCO2) to determine the degree of mineralization to CO2, water and inorganic salts under aerobic conditions. The test is designed for water-soluble, poorly water‑soluble (with special dispersion measures), and non‑volatile substances that are not inhibitory to the test microorganisms.

Key topics and technical requirements

• Test principle: static aqueous incubation with an inorganic test medium, a defined nominal carbon concentration (typically 10–40 mg C/L), and a mixed inoculum (activated sludge or environmental sources). CO2 evolved is trapped and quantified; results are reported as % of ThCO2.
• Temperature & environment: incubation in the dark or diffuse light at 20–25 °C (±2 °C); agitation and aeration with CO2‑free air (example flowrates given for typical volumes).
• Test media & reagents: composition of buffer and mineral solutions for 1 L medium is defined; use water with