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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:
4th April 2017 to 7th July 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
Guideline study to GLP certification with no deviations.

Data source

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

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
Deviations:
no
Principles of method if other than guideline:
Guideline study
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
5-chloropentan-2-one
EC Number:
227-565-8
EC Name:
5-chloropentan-2-one
Cas Number:
5891-21-4
Molecular formula:
C5H9ClO
IUPAC Name:
5-chloropentan-2-one
Test material form:
liquid
Remarks:
dark brown
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material:
5-Chloropentan-2-one (CAS-No.: 5891-21-4), Sanofi Chimie
- Purity: 95.9%

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations:
Nominal concentrations were 1, 3.2, 10, 32, 100 mg/L
Geometric mean concentrations were 0.43, 1.38, 4.3, 13.3, 45.9 mg/L

- Sampling method:
Samples collected from all test concentrations for analysis at 0 and 72 hours.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The test media were prepared just before introduction of the algae (= start of the test).

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Common name: Green algae
- Strain: Strain No. 61.81 SAG
- Age of inoculum (at test initiation): 4 days

Study design

Test type:
static
Water media type:
freshwater
Remarks:
OECD TG 201 medium
Limit test:
no
Total exposure duration:
72 h
Remarks on exposure duration:
None
Post exposure observation period:
None

Test conditions

Hardness:
No data (OECD TG 201 medium)
Test temperature:
23.0 – 23.6 °C
pH:
8.0 - 8.1 at test start and 4.5 - 9.9 at test end
Dissolved oxygen:
No data (OECD TG 201 medium)
Salinity:
Not applicable
Conductivity:
No data (OECD TG 201 medium)
Nominal and measured concentrations:
Nominal concentrations were 1, 3.2, 10, 32, 100 mg/L
Geometric mean concentrations were 0.43, 1.38, 4.3, 13.3, 45.9 mg/L
Details on test conditions:
TEST SYSTEM
- Initial cells density: approx. 5000 algal cells per mL test medium
- Control end cells density: 1.26 * 10^6 cells/ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes (OECD TG 201)

OTHER TEST CONDITIONS
- Photoperiod: Continuous illumination
Reference substance (positive control):
yes
Remarks:
Potassium dichromate (K2Cr2O7)

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 45.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 45.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
yield
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
> 45.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
23.6 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
yield
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
41.8 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
16.1 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
yield
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
13.3 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
13.3 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
yield
Key result
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
45.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
45.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
yield
Details on results:
- Exponential growth in the control (for algal test): yes
Results with reference substance (positive control):
- Results with reference substance valid? Yes
- Potassium dichromate 72 hour EC50 (growth inhibition): 1.12 mg/l
Reported statistics and error estimates:
Based on the calculated cell densities, the 72 hour ErC50 (growth) and the 72 hours EyC50 (yield), the corresponding EC20 and EC10 values and where possible their 95 %-confidence limits were calculated by non-linear regression. For the determination of the 72 hours LOEC and the 72 hours NOEC, the calculated growth rates and yields at each test concentration were tested for significant differences compared to the control values by Williams t-test (yield and growth rate). The software used to perform the statistical analysis was ToxRat Professional, Version 3.2.1, ToxRat Solutions GmbH.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The reliable (Klimisch 1) OECD 201 Guideline study on algal growth inhibition reported a 72-hr EC50 of > 45.9 mg/l and an EC10 of 41.8 mg/L based on growth of Pseudokirchneriella subcapitata (measured geometric mean).
Executive summary:

 


The reliable OECD 201 Guideline algal growth inhibition study was undertaken to GLP standards. The measured concentrations in the nominal test concentrations of 10, 3.2 and 1.0 mg test item/L were below the limit of quantification. All reported results refer to geometric mean concentrations, since the test item concentrations were not within ± 20% of the nominal concentrations during the test.


The following results for the test item were determined:





























EndpointNOECLOECEC10EC20EC50
Growth rate13.3 mg/l45.9 mg/l41.8 mg/l>45.9 mg/l>45.9 mg/l
Yield13.3 mg/l45.9 mg/l16.1 mg/l23.6 mg/l>45.9 mg/l