Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
21 Mar 2018 to 20 Apr 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation))
Version / remarks:
OECD Guideline 209. "Activated Sludge, Respiration Inhibition Test (Carbon and
Ammonium Oxidation)”, adopted 22 July 2010.
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
Purity/Composition: 99.73%

Sampling and analysis

Analytical monitoring:
not specified

Test solutions

Vehicle:
not specified
Details on test solutions:
First full test: Six concentrations: 10, 22, 56, 100, 220 and 560 mg/L (See deviation in Appendix 7).
Second full test: Seven concentrations: 4.8, 10, 22, 46, 100, 220 and 480 mg/L.

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage

Study design

Test type:
not specified
Water media type:
freshwater
Remarks:
Tap water purified by reverse osmosis (Millipore Corp., Bedford, Mass., USA).
Limit test:
yes
Total exposure duration:
3 h

Test conditions

Test temperature:
First Full Test: 20 ± 2°C.
Second Full Test: between 17.4 and 21.0°C.
pH:
7.5 ± 0.5.
Dissolved oxygen:
dissolved oxygen concentration at the start was above 60-70% saturation
Nominal and measured concentrations:
First full test: Six concentrations: 10, 22, 56, 100, 220 and 560 mg/L (See deviation in Appendix 7).
Second full test: Seven concentrations: 4.8, 10, 22, 46, 100, 220 and 480 mg/L.
Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
NOEC
Effect conc.:
4.8 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Duration:
3 h
Dose descriptor:
EC10
Effect conc.:
ca. 32 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
ca. 232 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Details on results:
EC20 64 mg/L
Results with reference substance (positive control):
The batch of activated sludge was tested for sensitivity with the reference item 3,5-dichlorophenol, and showed normal sensitivity.

Applicant's summary and conclusion

Validity criteria fulfilled:
no
Conclusions:
In conclusion, under the conditions of this present test PF-06961030 was not toxic to waste water bacteria (activated sludge) at or below a concentration of 4.8 mg/L (NOEC).
The EC10 was 32 mg/L (95% confidence interval: 26 - 39 mg/L).
The EC20 was 64 mg/L (95% confidence interval: 54 - 73 mg/L).
The EC50 was 232 mg/L (95% confidence interval: 210 - 258 mg/L).