Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
other: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
10.01.2012 to 07.02.2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
study performed with N-cocoyl glycine sodium salt
Justification for type of information:
Hostapon SG and Acylglycinate GCK-12H-T are structurally closely related UVCB substances, which differ predominantly in the counterion (sodium resp. potassium). As the counter-ion itself is not expected to have any significant adverse effect contributing to substance toxicity, it can be assumed that the results obtained with Hostapon SG for this specific endpoint also apply to Acylglycinate GCK-12H-T.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Dr. U. Noack-Laboratorien, Käthe-Paulus-Straße 1, D-31157 Sarstedt, Germany

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid - liquid: aqueous solution
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and of test material: Clariant Produkte (Deutschland) GmbH, Corporate Product Stewardship, Am Unisys-Park 1, D- 65843 Sulzbach am Taunus, Germany

STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature, protected from light, in original container

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: no

FORM AS APPLIED IN THE TEST (if different from that of starting material): Hostapon SG is a colourless aqueous liquid and was tested as such

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
- Laboratory culture: no
- Name and location of sewage treatment plant where inoculum was collected: Municipal sewage treatment plant of D-31137 Hildesheim (Germany)
- Preparation of inoculum for exposure: The activated sludge was washed twice with autoclaved tap water and concentrated to a dry sludge concentration of 3.0 g/L +/- 10%
- Pretreatment: no
- Initial biomass concentration: 3.05 g dry solids/L sludge; dry solid concentration in test solution: 1.53 g/L

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h

Test conditions

Test temperature:
20.5°C
pH:
7.5 +/-0.5
Dissolved oxygen:
>=60% of air saturation
Nominal and measured concentrations:
100, 180, 320, 580, and 1000 mg a.i./L nominal
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer flask
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass/1000 mL/-/500 mL
- Aeration: aeration of test vessels by shaking
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): no vehicle used
- Sludge concentration (weight of dry solids per volume): 3.05 g dry solids/L sludge

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: nutrient solution: synthetic waste water according to OECD Guideline 209

OTHER TEST CONDITIONS
- Adjustment of pH: no

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): respiration inhibition

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Justification for using fewer concentrations than requested by guideline: -
- Range finding study: performed
- Test concentrations: 10, 100, and 1000 mg a.i./L
- Results used to determine the conditions for the definitive study: yes
Reference substance (positive control):
yes
Remarks:
Copper (II) sulphate pentahydrate p.a.

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
3 h
Dose descriptor:
NOEC
Effect conc.:
320 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
inhibition of total respiration
Key result
Duration:
3 h
Dose descriptor:
EC10
Effect conc.:
372 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
inhibition of total respiration
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
791 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
inhibition of total respiration
Results with reference substance (positive control):
The EC50 for respiration inhibition with the reference item copper (II) sulphate pentahydrate yielded a value of 129 mg/L. This value was within the validity range of 53-155 mg/L and thus the validity criterion for this aspect is fulfilled..
Reported statistics and error estimates:
The NOEC was determined determined via one way analysis of variance and Dunett's test. The EC-values of the Hostapon SG were calculated by sigmoidal dose-respnse regression. The EC50-value of the reference item was calculated by linear regression using the software GraphPad Prism5, GraphPad Software, Inc..

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The NOEC-, EC10, and EC50-values for the respiration inhibition of Hostapon SG were determined to be 320, 372, and 791 mg a.i./L nominal. As Hostapon SG and acylglycinate GCK-12H-T differ only in the counterion (sodium-potassium), it can be assumed that the obtained results with Hostapon SG also apply to acylglycinate GCK-12H-T.
Executive summary:

The toxicity of Hostapon SG to activated sludge was investigated in a study conducted according to OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test). Activated sludge from a municipal sewage treatment plant treating predominantly domestic waste was exposed to Hostapon SG at different concentrations (range: 100 to 1000 mg a.i./L nominal). After 3 h of incubation the inhibition of respiration was determined in comparison to a set of test solutions without any test substance. The NOEC value for inhibition of total respiration was determined to be 320 mg a.i./L nominal, respectively. The corresponding EC10 and EC50 values were 372 and 791 mg a.i./L nominal, respectively. As Hostapon SG and acylglycinate GCK-12H-T differ only in the counterion (sodium-potassium), it can be assumed that the obtained results with Hostapon SG also apply to acylglycinate GCK-12H-T.

The study is regarded as reliable with restriction and satisfies the requirements of the guideline. The restriction is based on the fact that the results were not obtained with the test item here under investigation but from a very similar substance.

Results Synopsis

Test organism: activated sludge from a municipal sewage treatment plant

NOEC: 320 mg a.i./L

EC10: 372 mg a.i./L

EC50: 791 mg a.i./L (nominal each)

Endpoint(s) Effected: respiration