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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:
weight of evidence
Study period:
Dec. 8, 1992-Dec. 11, 1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: 88/302/EWG
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Source (laboratory, culture collection): Institut fur Wasser-, Boden- und Lufthygiene, Berlin

ACCLIMATION
- Acclimation period: 3 days

Study design

Test type:
static
Total exposure duration:
72 h

Test conditions

Test temperature:
24 ± 2 °C
pH:
7.7-9.0
Nominal and measured concentrations:
0, 0.6, 2.4, 10, 40, and 160 mg/L
Details on test conditions:
TEST SYSTEM
- Initial cells density: 2 x 10^4 cells/ml
- Control end cells density: 95 x 10^4 cells/ml
- No. of vessels per concentration (replicates): 8
- No. of vessels per control (replicates): 8

OTHER TEST CONDITIONS
- Light intensity and quality: 8000 Lux

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
other: EbC50
Effect conc.:
47.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Key result
Duration:
72 h
Dose descriptor:
other: ErC50
Effect conc.:
127.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
2.4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Details on results:
The pH as measured at the end of the experiment was very high (pH=9.0), however, as growth was not affect, the experiment was considered valid.

Any other information on results incl. tables

Cell count ( x 104cells/ml)

Concentration (mg/L)

0 hrs

24 hrs

48 hrs

72 hrs

Control

2

8

29

95

0.6

2

8

30

89

2.4

2

9

28

85

10

2

9

27

75

40

2

8

20

48

160

2

7

9

8

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72-hr NOEC for algae was 2.4 mg/L. The 72-hr EbC50 was 47.3 mg/L, and the 72-hr ErC50 was 127.9 mg/L for algae.
Executive summary:

Scenedesmus subspicatus was exposed to concentrations of 0, 0.6, 2.4, 10, 40, or 160 mg/L of test substance for 72 hrs. The cell concentration was measured at 24, 48, and 72 hrs. The 72-hr NOEC for algae was 2.4 mg/L. The 72-hr EbC50 was 47.3 mg/L, and the 72-hr ErC50 was 127.9 mg/L for algae. The NOEC of 2.4 mg/L does not require normalization since the compound tested was C11.6 LAS.