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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
Study period:
2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study conducted according to OECD Guidelines, with no or minor deviations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2015

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
Batch SC00008199
Purity 99.6%
Expiry date 2015-02-26

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes
Details on test solutions:
5 concentrations were tested in a geometrical series with a dilution factor of 3.16: 0.250 - 0.790 - 2.50 - 7.90 - 25.0 mg/L

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

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

Test conditions

Nominal and measured concentrations:
Nominal: 3.16: 0.250 - 0.790 - 2.50 - 7.90 - 25.0 mg/L
Details on test conditions:
With regard to the volatility of the test item, sealed glass flasks without headspace were used to reduce losses of the test item.
Reference substance (positive control):
yes
Remarks:
Potassium Dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
2.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
7.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
6.81 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: (3.98 - 7.84)
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
7.52 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: (4.43 - 7.88)
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
8.92 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: (7.98- 16.5)
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
2.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
7.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
6.18 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: (2.90-18.5)
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
6.56 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: (2.69- 17.7)
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
7.39 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: (2.56- 17.4)
Details on results:
The measured concentrations of Cumin Nitrile at the start and end of the exposure were in the range of 86 % to 105 % of the nominal values. Therefore, all effect values given are based on the nominal test item concentrations.
Results with reference substance (positive control):
Closed test vessels without headspace were used to mimic testing a volatile test article and the results compared with the standard "open" system with headspace. The data of both set-ups were consistent (see attached full study report for details) indicating that the use of a modified test system to reduce losses of the test item through volatility (completely filled and sealed) is expected to give results consistent with that obtained in a conventional system. As such it can be considered that the results obtained from the definitive test give a reliable result for the test item.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The preferred observational end point in this study is algal growth rate inhibition because it is not dependent on the test design (ECHA guidance Chapter R.7b v1.1). The EU CLP regulation (No 1272/2008 and its adaption 286/2011) also states that classification should be based on the ErC50. The preferred observational endpoint in long-term studies is the EC10 value because it is derived from the dose response curve. In contrast the NOEC depends on the experiment design (e.g. the concentrations used in the test). Thus the 72-h EC50 of 8.92 mg/L and EC10 of 6.81 mg/L based on growth rate are used for classification purposes.