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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
Study period:
1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study without detailed documentation

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
Stock solution of 100 mg/L prepared and diluted with test medium accoridng to guideline

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Source (laboratory, culture collection): Institute for plant physiology, University of Göttingen

Study design

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

Test conditions

Test temperature:
21°C
pH:
7.4 - 9.2
Nominal and measured concentrations:
Nominal: 0 (control), 0.01, 0.032, 0.1, 0.32, 1.0, 3.2, 10.0, 32.0 and 100.0 mg/L
Details on test conditions:
Water quality parameters and dilution water (test medium) in accordance with test guideline
Ligh regime: continuous light
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
1.2 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.:
4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.52 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
1.8 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Details on results:
see table

Any other information on results incl. tables

concentration
[mg/L]
area under the growth curve inhibition of algae growth compared to control
[%]
Growth rate inhibition of growth rate compared to control
[%]
control 697222 1.41
0.01 716667 -7.5 1.42 -0.65
0.032 681111 0.2 1.41 0.55
0.10 723333 -8.4 1.43 -0.87
0.32 665556 1.5 1.40 1.10
1.0 546667 20.9 1.33 5.73
3.2 134444 76.5 0.87 38.78
10.0 10000 98.0 0.00 100.00
32.0 10000 99.6 0.00 100.00
100.0 11111 99.5 0.04 97.52

negative values considered as enhancement of growth compared to the control

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72-h ErC10 and ErC50 to Desmodesmus subspicatus were determined to be 1.2 and 4.0 mg/L, respectively. The substance is acutely harmful to freshwater green algae.