Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The influence of the test substance on the respiration rate of activated sludge was investigated after a contact time of 3 hours.

The study procedure was based on OECD Guideline No. 209, adopted April 4, 1984, EEC Directive 67/548 amended November 18, 1987 (87/302), Part C, Publication No. L133, adopted May 30, ·1988 and ISO Standard 8192 (2007).

An initial loading rate of 200 mg/l was followed by a mixing (vortex) and a stirring period of 24-25 hours in the test bottle. Subsequently, synthetic sewage feed and sludge were added resulting in a final loading rate of 100 mg/l.

A loading rate of 100 mg/l was tested in duplicate. Optimal contact between the test substance and test medium was ensured applying continuous aeration and stirring.

No significant inhibition of respiration rate of the sludge was recorded at 100 mg per litre. The duplicate measurement showed 12% inhibition of respiration rate of sludge. Therefore, no further testing was needed.

Since all criteria for acceptability of the test were met, this study was considered to be valid.

In conclusion, under the conditions of this present test, the EC20-value for the test substance was greater than the loading rate of 100 mg/1, the regulatory limit concentration.

Key value for chemical safety assessment

Additional information