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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:
08 September 1998 to 11 September 1998
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted to recent EU test guidance in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report date:
1998

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Details on test material:
- Name of test material (as cited in study report): T-9601
- Physical state: Powder
- Analytical purity: 94.7
- Lot/batch No.: HI-295
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
Not applicable.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Analysis of the only test concentration (8 mg/l) plus a control; additional analysis of the test concentration 8 mg/l without algal inoculum, at test start and after 72 hours of exposure.

Test solutions

Vehicle:
no
Details on test solutions:
To produce the only test concentration (8 mg/l), the test substance was weighed into water, treated in an ultrasonic bath for 1 hour and afterwards stirred for 24 hours on a magnetic stirrer. To remove undissolved particles, the resulting suspension was filtered using a folded filter of the pore size 7-12 um.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
Species: Scenedesmus subspicatus CHODAT
Origin: Institute of Plant Physiology, University of Gottingen
Cultivation (stock cultures, precultures, test cultures): In a light chamber at 23 ± 2 °C and with a quantum flux which equals 120 μE/m-2s.
Water for dilution: deionised water

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h
Post exposure observation period:
No post exposure observation period

Test conditions

Hardness:
Not reported.
Test temperature:
Not reported.
pH:
8.2 - 10.3
Dissolved oxygen:
Not reported.
Salinity:
Not applicable.
Nominal and measured concentrations:
8 mg/l (nominal)
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 300ml
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionized water

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: [counting chamber; electronic particle counter; fluorimeter; spectrophotometer; colorimeter] Microcellcounter

The test solutions are incubated for a period of 72 hours, during which the cell density in each is measured at every 24 hours. The inhibition of growth and growth rate in relation to a control is determined after 72 hours of incubation.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 3.75 mg/L
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 3.75 mg/L
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
3.75 mg/L
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
3.75 mg/L
Basis for effect:
growth rate
Details on results:
The above test result refers to a concentration of the test substance, which was calculated directly from analytically determined TOC values. According to the relevant product information, 1 mg/1 TOC equals to 1.5 mg/l of the test substance (structural formula: C22H19N502; molecular weight: 385.4 g/mole).
Results with reference substance (positive control):
Not applicable.
Reported statistics and error estimates:
Not reported.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
No toxic effects against algae at 3.75 mg/l (maximum water solubility under exposure conditions).
Executive summary:

Study data conducted to EU test guidance 92/69/EEC part C.3 and in compliance with GLP.

Study found no toxic effects against algae at 3.75 mg/l (maximum water solubility under exposure conditions).