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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:
May - Jul 1996
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD guideline under GLP
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Principles of method if other than guideline:
not relevant
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Triamin-Dihydrochlorid
- Analytical purity: 98.4%
- Lot/batch No.: 450790

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

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

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
6.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 5.9 - 7.2
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
18.6
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 13.0 - 24.1

Any other information on results incl. tables

Table 1: Inhibition of the growth of Scenedesmus subspicatus after 72 hours exposure to ZK 156454

Concentration (mg/L)  Inhibition in percent
of ZK 156454   biomass (inteqral) growth rate
0.0  0 0
3.1 28.7 9.4
6.2  47.1  18.1
12.5  69.8 31.6
25.0  87.0 59.8
49.9  94.4  86.6

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
ZK 156454 had an inhibitory, concentration-related effect on the growth of Scenedesmus subspicatus. The EbC50 (biomass) was 6.5 (5.9-7.2) mg/L, the ErC50 (growth rate) was 18.6 (13.0-24.1) mg/L, including the 95% confidence limits.
Executive summary:

The purpose of this study was to determine the effects of the test compound Triamin.Dihydrochlorid (ZK 156454) on the

growth of the green algae Scenedesmus subspicatus. The study was conducted in agreement with the OECD guideline no. 201.

The test substance ZK 156454 was incubated in an aqueous solution including nutrients with an algae population of Scenedesmus subspicatus for a test duration of approximately 72 hours.

The nutrient solution was made up of mainly nitrate, phosphates and some trace elements. The test concentrations were 0, 3.1, 6.2, 12.5, 25.0 and 49.9 mg/I (nominal). The algae were exposed to each concentration in triplicate. Six vessels were prepared for the control. The algae were incubated in an incubator shaker under continuous light.

As a parameter for the growth of the algae population, the cell concentrations of the test and control solutions were counted with an electronic particle counter ("Coulter Counter"). The increase of biomass and the growth rate were calculated on the basis of the cell counts. The calculated biomass and growth rate of each concentration were compared to those of the controls, and the inhibition was calculated. ZK 156454 had an inhibitory, concentration-related effect on the growth of Scenedesmus subspicatus.