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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-Guideline study.

Data source

Reference
Reference Type:
other company data
Title:
Unnamed
Year:
2011

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Qualifier:
according to
Guideline:
other: EU Commission Directive 92/69/EEC, C. 3
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Composition: 100 % active ingredient based on N,N'-1,6-hexanediylbis[N-(2,2,6,6-tetramethyl-piperidin-4-yl)-formamide]
Stability of test concentration/s during exposure: Examined by chemical analysis (HPLC)at 0 and 72 hours.

Sampling and analysis

Analytical monitoring:
yes

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
Desmodesmus subspicatus (formerly Scenedesmus subspicatus) Strain No. 86.81 SAG.
Strain of the test species obtained from 'The Collection of Algal Cultures' of the Institute of Plant Physiology at the University of Göttingen (Germany).

Study design

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

Test conditions

Hardness:
22.5 mg/L CaCO3
Test temperature:
21-24°C with a maximum fluctuation of +/- 2°C
pH:
8.1
Nominal and measured concentrations:
Concentrations tested were 6.3, 12.5, 25, 50, 100 and 200 mg/L (nominally). Effective concentrations ranged from 97.4 % to 105.2 % of nominal values at 72 hours.

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
298 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 274-343mg/L,95%-cl
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
164 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 153-171mg/L,95%-cl
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
100 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
200 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
181 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 176-185mg/L, 95%-cl
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
116 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 105-124mg/L, 95%-cl
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
100 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
200 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
biomass
Details on results:
NOEC and LOEC determined according to Williams Multiple Sequential t-Test Procedure and Welch-t test for Inhomogeneous Variances with Bonferroni-Holm Adjustment.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
According to OECD 201, the factor of the biomass parameter, measured in the control between 0 and 72 h, must be at least 16.
With the current test it was found to be 119.0. The test fulfils this validity criterion.
Evaluation of the section-by-section growth rates:
The mean of the replicate coefficients of variation in the section-by-section growth rate was: 15.1%.
According to OECD 201, the mean coefficient of variation, measured in the control from 0 to 72 h, must not be higher than 35%. The test fulfils this validity criterion.
The coefficient of variation of the mean specific growth rate replicates in the control between 0 and 72 h was: 0.5%.
According to OECD 201, the coefficient of variation of the mean specific growth rate, measured in the control from 0 to 72 h, must not exceed 7%. The test fulfils this validity criterion.