Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The 30 -min EC50 value is >1000 mg/L in activated sludge from a municipal STP.

Key value for chemical safety assessment

EC50 for microorganisms:
1 000 mg/L

Additional information

The toxicity of 1,2,3,4 -tetrahydroisoquinoline was determined in a GLP-compliant Activated Sludge respiration Inhibition test according to OECD guideline 209. In this study, activated sludge from the aeration tank of a municipal wastewater treatment plant was exposed to nominal concentrations of 10, 100, 240, 500 and 1000 mg/L and a blank control for 30 minutes. No analytical verification of nominal concentrations was performed. After the exposure period oxygen consumption rates were measured using an oxygen electrode and the percentage inhibition of the oxygen consumption was estimated by comparison of the rate with that of a control mixture containing no test material (blank control). The sensitivity of the activated sludge was checked with the reference substance 3,5 dichlorophenole. After 30 minutes exposure, a maximum 47% inhibition of oxygen consumption rate was noted at the highest concentration of 1000 mg/L. Based on these findings the 30 -min EC50 value is determined at >1000 mg/L.