Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1988-05-30
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was not conducted according to guideline/s and GLP but the report contains sufficient data for interpretation of study results.
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study
Qualifier:
no guideline followed
Principles of method if other than guideline:
EEC L 133, p. 118-122 (30 May 1988) (Deviations- 1) a settled sludge was used 2) due to the poor solubility at test concentrations, direct weighed amounts were added to the test medium instead of a stock
GLP compliance:
no
Analytical monitoring:
no
Details on sampling:
not applicable
Test organisms (species):
other: industrial activated sludge
Details on inoculum:
Activated sludge was collected from the sewage treatment plant and prepared according to the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation.
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Nominal and measured concentrations:
nominal- 2.15, 3.3, 13, 32.5, and 109 mg/L.

Details on test conditions:
Activated sludge was collected from the sewage treatment plant and prepared according to the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation. Flasks (250 mL BOD) with gas inlet were used as test vessels. Declorinated drinking water (20 +/- 2C) were used for the 3 hour test.

The test material concentrations were: 2.15, 3.3, 13, 32.5, and 109 mg/L. The sludge concentration was 1.5 g/L.

Oxygen consumption per hour was determined and recorded in mg/L with ORION-Electrode type 97-08 Microprocessor Ionalizer 901.

The inhibitory concentrations were calculated based on the measured time-dependent oxygen consumption of a blank and test solutions.
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol at 3.2, 10 and 32 mg/L
Duration:
3 h
Dose descriptor:
other: IC20
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Inhibitions were calculated on the basis of the measured time depend oxygen consumption of a blank and test solution.
Remarks on result:
other: no data
Duration:
3 h
Dose descriptor:
IC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Inhibitions were calculated on the basis of the measured time depend oxygen consumption of a blank and test solution.
Remarks on result:
other: no data
Duration:
3 h
Dose descriptor:
other: IC80
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Inhibitions were calculated on the basis of the measured time depend oxygen consumption of a blank and test solution.
Remarks on result:
other: no data
Duration:
3 h
Dose descriptor:
EC10
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Inhibitions were calculated on the basis of the measured time depend oxygen consumption of a blank and test solution
Details on results:
Graphically determined data

Results with reference substance (positive control):
IC50=13 mg/L

The % inhibition for the test substance was 6, 10, 6, 9 and 10% for concentrations of 2.15, 3.30, 13.0, 32.5 and 109 mg/l.

The IC50 for the reference substance, 3,5 -dichlorphenol, was 13 mg/l.

Conclusions:
Under these test conditions the IC50 is >100 mg/L.

Executive summary:

This study determined the inhibitory concentration of TK 10490 on the respiration of aerobic waste water bacteria. The test lasted for 3 hours at 20 +/-2C. The IC50 was >100 mg/l, the highest concentration tested.

Description of key information

Based on an activated sludge respiration inhibition study, the 3-hour IC10 and IC50 for BADGE and BADGE-related resins is 100 mg/L and > 100 mg/L, respectively. 

Key value for chemical safety assessment

EC50 for microorganisms:
100 mg/L
EC10 or NOEC for microorganisms:
100 mg/L

Additional information

Two microorganism studies were examined for BADGE and both were deemed reliable and useful for risk assessment. One study examined the response of respiration inhibition of activated sludge over a 3 hour exposure period, while the other study measured growth inhibition of Pseudomonas putida over an 18-hour exposure period. The activated sludge inhibition test reported a 3-hour IC20, IC50 and IC80 all >100 mg/L BADGE. Furthermore, inhibition of respiration did not exceed 10% at the highest dose level (nominal) of 109 mg/L BADGE. According to the study report and the growth inhibition study with P. putida reported an 18-hour NOEC of 42.6 mg/L BADGE. The value of 100 mg/L was selected as the key parameter for this endpoint, since according the ECHA guidance (R.7.8.1.7.1), the results of the cell multiplication inhibition test with P. putida should be used for calculation of the PNECmicro-organisms only in cases where no other test results are available.