Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

3-hour EC50 of 430 mg/L and aNOEC of 100 mg/L.

Key value for chemical safety assessment

Additional information

A study was performed to assess the effect of the test material on the respiration of activated sewage sludge. The method followed that described in the OECD Guidelines for Testing of Chemicals (1984) No 209 "Activated Sludge, Respiration Inhibition Test", Method C.1 of EEC Commission Directive 88/302/EEC and US EPA Draft Ecological Effects Test Guidelines OPPTS 850.6800. Data indicated that the test material was known to react violently on contact with water forming N-butylpyridinium chloride, hydrochloric acid and
alumina. The study was therefore mainly performed on the test material degradation products and not the parent test material.
Following a preliminary range-finding test, activated sewage sludge was exposed to an aqueous solution of the test material degradation products at concentrations of 10, 32, 100, 320 and 1000 mg/L for a period of 3 hours at a temperature of approximately 21°C with the addition of a synthetic sewage as a respiratory substrate.
The rate of respiration was determined after 30 minutes and 3 hours contact time and compared to data for the control and a reference material, 3,5-dichlorophenol.

The effect of the test material degradation products on the respiration of activated sewage sludge gave a 3-hour EC50 of 430 mg/L. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 100 mg/L.