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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:
1993
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1996

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: 87/302/EEC page 89-94 Algal Inhibition test
Principles of method if other than guideline:
Determination of EbC 50 (0-72 h) : Concentration at which reduced the growth of algae by 50% in relation to control.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
impurity
Type:
impurity
Type:
impurity
Test material form:
liquid

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Composite samples of each test concentration were drawn by mixing identical volumes of the test. Solutions taken from the approximate center of the test vessels.
They were taken inunediately before exposure and after 72 hours exposure and kept at - 18*'C to - 22°C until analysis.

Test solutions

Vehicle:
yes
Remarks:
28.8 mg N,N-dimethylformamide(DMF)/l and 1.2 mg polyoxy-ethylene-sorbitanmonooleate {TWEEN 80)/L
Details on test solutions:
0.123, 0.37, 1.1, 3.3, 10 and 30 mg/L (nominal)
<0.05, 0.2, 0.5, 1.7, 7.7 and 18.8 mg/L (actual)

Test organisms

Test organisms (species):
Scenedesmus sp.
Details on test organisms:
Collection of algae cultures
Pflanzenphysiologisches Institut
University
Nikolausberger Weg 18
D-3400 Göttingen
Germany

Study design

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

Test conditions

Test temperature:
23 ± 1°C.
pH:
7.8-7.9 initial
8.2-9.1 after 72 hours
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
4.3 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.5 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
test mat.
Basis for effect:
cell number
Details on results:
95 % confidence llmit: 0.49 - 23.2 mg/l
Reported statistics and error estimates:
The EC-50 values were calculated according to the maximun likelihood method, probit model (Mc Cullagh, P., Neider, J.A., 1983: Generalized linear modeis, Chapman & Hall, London)

Applicant's summary and conclusion

Conclusions:
EC50 was 4.3 mg/L after 72 hours.
Executive summary:

EC50 was 4.3 mg/L after 72 hours.