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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:
May - July 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
impurity
Type:
impurity
Type:
impurity
Type:
impurity
Test material form:
liquid
Details on test material:
UVCB substance
Specific details on test material used for the study:
Givaudan Product Code: 6347001
Batch Number: PE00138468

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
The determination of the actual test item concentrations was based on the measurement of the sum of all components of the test item. For this, duplicate samples were taken from each treatment at the start of the test. At the end of the test (after 72 hours), stability samples (containing algae) were taken in duplicate from all test concentrations and from the control.

Test solutions

Vehicle:
no
Details on test solutions:
Reconstituted test water (AAP Medium) prepared according to the test guidelines was used for algal cultivation and testing. Analytical grade salts were dissolved in sterile purified water.
Since the test item was determined to be volatile, glass stoppered Erlenmeyer flasks were used completely filled (without headspace) with about 60 mL of test medium and tightly sealed with glass stoppers to avoid losses of the volatile substance by evaporation (closed system).

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h

Test conditions

Hardness:
The water hardness (calculated) of the test water was 0.15 mmol/L (= 15 mg/L as CaCO3).
Test temperature:
The water temperature during the test was maintained at 24 °C.
pH:
The pH of the test media was in the range of 7.4 to 7.8 during the test period .
Nominal and measured concentrations:
Based on the results of the range-finder the following nominal concentrations of JASMONYL LG were selected for the main test: 4.6, 10, 22, 46 and 100 mg/L, applying a spacing factor of 2.2. The main test was performed in a closed system. Additionally, a control (test water without test item) was tested in parallel.
Details on test conditions:
Range-finding Test:
For determination of the appropriate test concentrations for the main test, a range-finding test with nominal test item concentrations of 1.0, 10 and 100 mg/L was performed in a closed system. For this, three replicates per treatment were tested. The test medium of the highest concentration of 100 mg/L was stirred until complete dissolution for one hour in a closed vessel, at room temperature in the dark. The test media of the two lower concentrations were prepared in a series of further dilution steps. To better understand the behavior and fate of the test item under the test conditions, additional test vessels with test medium at a concentration of 10 mg/L were incubated under the following conditions: test medium without algae under light conditions and test medium without algae in the dark. The analytical results showed that the test item does not undergo photolytic degradation and that there was no adsorption of the test item onto the algae.
Reference substance (positive control):
yes

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
73 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
40 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
Effects based on yield were also reported (see attached full study report). However, the preferred observational endpoint in the algal inhibition study is growth rate because it is not dependent on the test design (ECHA guidance Chapter R.7b v 2.0, OECD 201 Guidelines). The guideline includes the additional response variable of yield, to satisfy current regulatory requirements in some countries. The EU CLP regulation (No 1272/2008 and its adaption 286/2011) also states that classification should be based on the ErC50. Thus only the effects based on growth rate are presented in the above "effects concentration" table.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The impact of the test item JASMONYL LG on the growth of the freshwater green algal species Pseudokirchneriella subcapitata resulted in a 72-h ErC50 of 73mg/L, 72-hour ErC10 of 40 mg/L, 72-h EyC50 of 40mg/L, 72-h EyC10 of 20 mg/L and NOEC (both growth rate and yield) of 10 mg/L.

The preferred observational end point in the algal growth inhibition test is growth rate because it is not dependent on the test design (ECHA guidance Chapter R.7b v2.0, OECD 201 Guideline). 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 strongly depends on the experiment design (e.g. the concentrations used in the test). Thus the 72-h EC50 and EC10 based on growth rate are used for classification purposes, which were determined in this study to be 73 and 40 mg/L respectively.