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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:
From June,19 2017 to September 22,2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
Batch Number: VE00463145
Appearance: Colorless to pale yellow liquid
Purity: 99.9 % (sum of the isomers)
Expiration Date: April 06, 2018

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
As the test item is a volatile substance, the test was performed using glass stoppered Erlenmeyer flasks (closed system) completely filled with test medium, minimizing the air space in the flasks and avoiding potential losses of test item by evaporation.

Test solutions

Vehicle:
yes
Details on test solutions:
Since the test item is a liquid with low water solubility, the slow-stirring method was applied for preparation of a saturated test item solution.
For this, the test item with a density of 0.8957 g/cm3 (at 20°C) was carrefully applied on to the surface of the test water at a loading rate of 100 mg/L.
The equilibrated aqueous phase with a loading rate of 100 mg/L, containing dissolved test item only, was used as the highest test concentration and was diluted with test water to obtain the dilutions 1:2, 1:4, 1:8 and 1:16.
Additionally a control (test water without test item) was tested in parallel.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
The test organism used for the study was Pseudokirchneriella subcapitat, Strain No. 61.81 SAG

Study design

Test type:
static
Water media type:
other: AAP Medium
Total exposure duration:
72 h

Test conditions

Hardness:
0.15 mmol/L (= 15 mg/L as CaCO3)
Test temperature:
24°C
pH:
7.5
Nominal and measured concentrations:
At the start of the main test, the highest concentrated test medium (i.e. the undiluted equilibrated test medium with a loading rate of 100 mg/L) was prepared following the slow-stirring method
(see Section 5.5 of the report) with a stirring period of 48 hours at room temperature in the dark. For this, 259 μL of test item were carefully applied (pipetted) onto the surface of 2320 mL test water.
This volume is equivalent to a loading rate of 100 mg/L, considering the density of the test item of 0.8957 g/cm3 (at 20 °C). No auxiliary solvent or emulsifier was used.
The equilibrated aqueous phase with a loading rate of 100 mg/L, containing dissolved test item only, was used as the highest test concentration and was diluted with test water to obtain the
test media with the lower test concentrations, i.e. the dilutions 1:2, 1:4, 1:8 and 1:16.
Additionally, a control (test water only) was run in parallel. The test media were prepared just before the start of the test.
Details on test conditions:
Based on the results of the range-finding test and in agreement with the Sponsor the following concentrations of SINODOR CQ were selected for the main test: the equilibrated test medium
with a loading rate of 100 mg/L and the dilutions 1:2, 1:4, 1:8 and 1:16. Additionally, a control (test water without test item) was tested in parallel.
Reference substance (positive control):
yes
Remarks:
Potassium Dichromate

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.11 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.028 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.023 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.072 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.04 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.023 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
biomass

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
A clear concentration-response relationship was observed for both biological endpoints growth rate and yield over the exposure period of 72 hours.
A statistically significant inhibitory effect on the growth rate and on the yield of the algae was observed at the end of the test at the concentrtaion of 0.044 mg/L, and above.
Executive summary:

 

 Endpoint after 72 Hours

Growth Rate [mg/L]

Yield [mg/L]

EC10

(95 % Confidence Interval)

 0.028 

(0.026-0.030)

0.040  

(0.037-0.043)

 

EC50

(95 % Confidence Interval)

  

>0.11  

n.d.

  

0.072 

(0.069-0.075)

 NOEC

0.023

0.023