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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was performed according to German national standard guidelines (no GLP, no analytics).
Cross-reference
Reason / purpose:
reference to same study
Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was performed according to German national standard guidelines (no GLP, no analytics).
Justification for type of information:
See read-across justification attached in section 13.2
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
other: DIN 38 412, L9
GLP compliance:
no
Analytical monitoring:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution of 1000 mg/l was prepared. The stock solution was prepared by dissolving 1000 mg test substance and 100 mg of the solubilizer Cremophor in dilution water. The test concentrations were then prepared by dilution with test water.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): 25 mg Cremophor/l
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): 0.5, 1.0, 2.5, 5.0, 10.0, 25.0 mg/l

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Strain: SAG 86.81
- Source (laboratory, culture collection): Algae collection Goettingen
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Test temperature:
21.3 °C
pH:
7.75 - 7.99
Nominal and measured concentrations:
Nominal test concentration (mg/l):
0 (control), 50, 10, 25, 50, 100, and 250
Details on test conditions:
TEST SYSTEM
- No. of organisms per vessel: 4
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to DIN 38412 L9


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: At 0, 24, 48, 72, and 96 hours after test start, the algae cell density was determined by spectro-fluorometrical measurement using an impulse fluorometer. The parameters pH, and temperature were determined at the end of the test. Also, at the end of the incubation period the algae cells were analyzed for signs of photosynthesis blockage by means of a spectrophotometrical scan at 300 - 780 nm.
Reference substance (positive control):
yes
Remarks:
Potassium chromate p.a.
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
21.6 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.:
9.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Reported statistics and error estimates:
The EC50 values were calculated according to the procedure of Tallaradia & Jacob (1979): The dose-response relation in pharmacology. Springer Verlag, 98-103.
Nominal test    fluorometer values after x hours
concentration
(mg/l) 0 / 24 / 48 / 72 / 96 /
-----------------------------------------------

S.Control / 12 / 43 / 117 / 370 / 799 /
Control / 12 / 45 / 122 / 357 / 762 /
5.0 / 13 / 44 / 104 / 273 / 649 /
10.0 / 13 / 43 / 101 / 255 / 639 /
25.0 / 13 / 41 / 91 / 216 / 530 /
50.0 / 13 / 32 / 38 / 40 / 57 /
100.0 / 12 / 18 / 15 / 13 / 11 /
250.0 / 11 / 6 / 4 / 4 / 4 /

S.Control = solvent control
*10000 cells/ml were introduced at the test start.


ECx values (in mg/l) after x hours of exposure

/ 72 h / 96 h /

EBC10 / 7.462 / 6.340 /
EBC50 / 18.581 / 15.676 /

ErC10 / 9.457 / 16.021 /
ErC50 / 21.624 / 25.887 /

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: DIN 38 412, L9
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Tetrahydrolinalool
- Lot/batch No.: 36-0589
Purity: no data
Water solubility: 320 mg/l at 25 °C

Sampling and analysis

Analytical monitoring:
no

Test solutions

Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution of 1000 mg/l was prepared. The stock solution was prepared by dissolving 1000 mg test substance and 100 mg of the solubilizer Cremophor in dilution water. The test concentrations were then prepared by dilution with test water.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): 25 mg Cremophor/l
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): 0.5, 1.0, 2.5, 5.0, 10.0, 25.0 mg/l

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Strain: SAG 86.81
- Source (laboratory, culture collection): Algae collection Goettingen

Study design

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

Test conditions

Test temperature:
21.3 °C
pH:
7.75 - 7.99
Nominal and measured concentrations:
Nominal test concentration (mg/l):
0 (control), 50, 10, 25, 50, 100, and 250
Details on test conditions:
TEST SYSTEM
- No. of organisms per vessel: 4
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to DIN 38412 L9


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: At 0, 24, 48, 72, and 96 hours after test start, the algae cell density was determined by spectro-fluorometrical measurement using an impulse fluorometer. The parameters pH, and temperature were determined at the end of the test. Also, at the end of the incubation period the algae cells were analyzed for signs of photosynthesis blockage by means of a spectrophotometrical scan at 300 - 780 nm.
Reference substance (positive control):
yes
Remarks:
Potassium chromate p.a.

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
21.6 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.:
9.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Reported statistics and error estimates:
The EC50 values were calculated according to the procedure of Tallaradia & Jacob (1979): The dose-response relation in pharmacology. Springer Verlag, 98-103.

Any other information on results incl. tables

Nominal test    fluorometer values after x hours
concentration
(mg/l) 0 / 24 / 48 / 72 / 96 /
-----------------------------------------------

S.Control / 12 / 43 / 117 / 370 / 799 /
Control / 12 / 45 / 122 / 357 / 762 /
5.0 / 13 / 44 / 104 / 273 / 649 /
10.0 / 13 / 43 / 101 / 255 / 639 /
25.0 / 13 / 41 / 91 / 216 / 530 /
50.0 / 13 / 32 / 38 / 40 / 57 /
100.0 / 12 / 18 / 15 / 13 / 11 /
250.0 / 11 / 6 / 4 / 4 / 4 /

S.Control = solvent control
*10000 cells/ml were introduced at the test start.


ECx values (in mg/l) after x hours of exposure

/ 72 h / 96 h /

EBC10 / 7.462 / 6.340 /
EBC50 / 18.581 / 15.676 /

ErC10 / 9.457 / 16.021 /
ErC50 / 21.624 / 25.887 /

Applicant's summary and conclusion