Reaction products of 1H-Imidazole-1-ethanol, 4,5-dihydro-, 2-(C7-C9 odd-numbered alkyl) derivs. and sodium hydroxide and chloroacetic acid

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reason / purpose for cross-reference:

read-across source

GLP compliance:

yes

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

560 mg/L

Nominal / measured:

nominal

Conc. based on:

other: expressed as solid content

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

589 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Recalculated for target

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

other: expressed as solid content

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 053 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Recalculated for target

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

- Combined limit/range-finding test: No inhibition of the respiration rate was observed at 20 mg/l and 200 mg/l expressed as solid content. At 2000 mg/l expressed as solid content the average inhibition of the respiration was 70%. There was no significant oxygen uptake from abiotic processes and the results at 2000 mg/l expressed as solid content with a nitrification inhibitor showed that the heterotrophic inhibition of the respiration rate was comparable to the total inhibition. Therefore, N-allylthiourea was not used in the final test.
- Final test: No statistically and biologically significant inhibition of the respiration rate of the sludge was recorded at 560 mg/L expressed as solid content (Bonferroni t-Test: α=0.05 Toxstat). At 1000 mg/l expressed as solid content 34% inhibition (mean value) of the respiration rate was observed.

Results with reference substance (positive control):

EC50 of 3,5-dichlorophenol:
- Combined limit/range-finding test: 5.6 mg/L
- Final test: 6.8 mg/L

Validity criteria fulfilled:

yes

Conclusions:

In accordance with OECD 209 (2010) and according to GLP principles the influence of a substane analogue (Amphoacetates C12) on the respiration rate of activated sludge was investigated after a contact time of 3 hours. The substance was not toxic to waste water (activated sludge) bacteria at a concentration of 560 mg/L (NOEC; based on solid content). This result is read across to Amphoacetates C8.

Executive summary:

In accordance with OECD 209 the influence of a substane analogue (Amphoacetates C12) on the respiration rate of activated sludge was investigated after a contact time of 3 hours. In a combined limit/range-finding test concentrations of 20, 200 and 2000 mg/l were tested. No statistically significant inhibition of the respiration rate of the sludge was recorded at the concentrations 20 and 200 mg/L. At 2000 mg/l, the average inhibition of the respiration was 70%. Therefore, a final test was performed at 100, 180, 320, 560 and 1000 mg/l. No statistically and biologically significant inhibition of the respiration rate of the sludge was recorded in this test at 560 mg/L (NOEC). At 1000 mg/L, the average inhibition of the respiration was 34%. The batch of activated sludge was checked for sensitivity by testing the reference substance 3,5-dichlorophenol, which showed normal sensitivity. The validity criteria were all fulfilled. This result is read across to Amphoacetates C8.

Description of key information

In accordance with OECD 209 (2010) and according to GLP principles the influence of a substance analogue (Amphoacetates C12) on the respiration rate of activated sludge was investigated after a contact time of 3 hours. The substance was not toxic to waste water (activated sludge) bacteria at a concentration of 560 mg/L (solid content; NOEC). This result was read across to Amphoacetates C8.

Key value for chemical safety assessment

EC50 for microorganisms:

1 053 mg/L

EC10 or NOEC for microorganisms:

589 mg/L

Additional information

In accordance with OECD 209 the influence of a substance analogue (Amphoacetates C12) on the respiration rate of activated sludge was investigated after a contact time of 3 hours. In a combined limit/range-finding test concentrations of 20, 200 and 2000 mg/l were tested. No statistically significant inhibition of the respiration rate of the sludge was recorded at the concentrations 20 and 200 mg/L. At 2000 mg/l, the average inhibition of the respiration was 70%. Therefore, a final test was performed at 100, 180, 320, 560 and 1000 mg/l (based on solid content). No statistically and biologically significant inhibition of the respiration rate of the sludge was recorded in this test at 560 mg/L (NOEC). At 1000 mg/L, the average inhibition of the respiration was 34%. The batch of activated sludge was checked for sensitivity by testing the reference substance 3,5-dichlorophenol, which showed normal sensitivity. The validity criteria were all fulfilled. This result was read across to Amphoacetates C8.