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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:
05 Dec 2016 - 11 Apr 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
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Remarks:
Medicines & Healthcare products Regulatory Agency, UK

Test material

Constituent 1
Chemical structure
Reference substance name:
1,4:3,6-dianhydro-2,5-di-O-methyl-D-glucitol
EC Number:
226-159-8
EC Name:
1,4:3,6-dianhydro-2,5-di-O-methyl-D-glucitol
Cas Number:
5306-85-4
Molecular formula:
C8H14O4
IUPAC Name:
1,4:3,6-dianhydro-2,5-di-O-methyl-D-glucitol
Test material form:
liquid

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: control and 100 mg/L
- Sampling method: duplicate samples were taken at 0 and 72 hours of the test.
- Sample storage conditions before analysis: The samples were stored frozen prior to analysis.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A 100 mg/L stock solution of the test substance was prepared by dissolving 100 mg of test substance in 1 L of dilution water.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control

Test organisms

Test organisms (species):
Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Common name: green algae
- Strain: CCAP 278/4
- Source (laboratory, culture collection): Culture Collection of Algae and Protozoa (CCAP), SAMS Research Services Ltd, Scottish Marine Institute, Oban, Argyll, Scotland.
- Method of cultivation: Master cultures were maintained in the laboratory by the periodic replenishment of culture medium. The master cultures were maintained under constant aeration and illumination at 21 ± 2 °C.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h
Post exposure observation period:
none

Test conditions

Test temperature:
24 ± 1 ºC
pH:
Control:
7.6 at 0 hours
8.4 at 72 hours

Test concentration 100 mg/L:
7.7 at 0 hours
8.5 at 72 hours
Nominal and measured concentrations:
0 and 100 mg/L (nominal concentration)
0 and 98.7 mg/L (measured concentrations at T = 0 h); 0 and 97.8 mg/L (at T = 72 h)
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 mL glass conical flasks
- Type (delete if not applicable): closed with polyurethane foam caps
- Material, size, headspace, fill volume: 250 mL
- Aeration: no, but constantly shaken at 150 rpm
- Initial cells density: 5 x 10^3 cells per mL
- Control end cells density: 8.2 x 10^5 cells per mL (mean)
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reverse osmosis purified deionized water and the pH adjusted to 7.5 with NaOH or HCl.

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: yes
- Photoperiod: continuous illumination
- Light intensity and quality: ca. 7000 lux; wave 380 – 730 nm

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Cell density was measured at 24, 48 and 72 hour using Coulter® Multisizer Particle Counter.


TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 0, 0.10, 1.0, 10, 100 mg/L
- Results used to determine the conditions for the definitive study: Maximum test concentration (100 mg/L) had no effect on algae growth.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Details on results:
Growth rate and yield of green algae P. subcapitata were not affected by the test item at a nominal test concentration of 100 mg/L over the 72-hour exposure period.
Results with reference substance (positive control):
72 h ErC50 = 1.4 mg/L; NOECr = 0.25 mg/L
72 h EyC50 = 0.6 mg/L; NOECy = 0.25 mg/L
Reported statistics and error estimates:
Student’s t-test incorporating Bartlett's test for homogeneity of variance (Sokal and Rohlf, 1981).

Any other information on results incl. tables

Cell Densities and Percentage Inhibition of Growth from the Range-finding Test:

Nominal Concentration
(mg/L)		 Mean Cell Densities (cells per mL) Inhibition Values (%)
0 h 72 h Growth rate Yield
control 9.06E+03 1.46E+06 - -
0.1 9.03E+03 1.25E+06 4 14
1 8.61E+03 1.34E+06 1 8
10 9.22E+03 1.26E+06 4 14
100 9.40E+03 1.27E+06 4 13

Applicant's summary and conclusion