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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
11 October 1999 - 14 October 1999
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II)
Deviations:
no
GLP compliance:
yes
Analytical monitoring:
no
Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION- Method: Test material was stirred in demineralized water for about 48 h to prepare a stock solution (nominal concentration = 125 mg/L)
Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM- Source (laboratory, culture collection): Obtained at regular intervals from SAG (Collection of algal cultures in Göttingen) and was kept in liquid culture in the Laboratory of Ecology at BASF AG Ludwigshafen
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Test temperature:
21-25 °C
pH:
8.0-8.8
Nominal and measured concentrations:
Nominal concentrations: 6.25, 12.5, 25, 50 and 100 mg/L
Details on test conditions:
TEST SYSTEM- Test vessel: - Material, size, headspace, fill volume: Erlenmeyer flasks (nominal volume 250 mL) plugged with gas permeable silicon sponge caps- Initial cells density: 10,000 cells/mL- No. of vessels per concentration (replicates): Triplicate- No. of vessels per control (replicates): Triplicate- No. of vessels per vehicle control (replicates): TriplicateGROWTH MEDIUM- Standard medium used: YesOTHER TEST CONDITIONS- Photoperiod: Artificial Iight, type universal white (e.g. OSRAM L 25), permanent illumination- Light intensity and quality: 60-120 µE/m2.s at a wavelength of 400-700 nmEFFECT PARAMETERS MEASURED (with observation intervals if applicable) : - Determination of cell concentrations: After 72 hours in a counting chamber (Neubauer improved) in replicate 1 of the inoculated control.- Chlorophyll measurement: In vivo chlorophyll-a-fluorescence (pulsed excitation with Iight flashes having a wavelength of 435 nm); fluorescence measured after 0, 24, 48 and 72 hours.
Reference substance (positive control):
yes
Remarks:
potassium dichromate
Duration:
72 h
Dose descriptor:
other: EbC10
Effect conc.:
23.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
other: EbC50
Effect conc.:
41.6 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
other: EbC90
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Key result
Duration:
72 h
Dose descriptor:
other: ErC10
Effect conc.:
31 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
other: ErC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
other: ErC90
Effect conc.:
> 100 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.:
12.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
25 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Results with reference substance (positive control):
EC50 (72 h) = 0.35 mg/L
Reported statistics and error estimates:
Duncan multiple range test was carried out at a 95 % significance level.
Validity criteria fulfilled:
yes
Remarks:
EC50 (72 h) of the control substance potassium dichromate was 0.35 mg/L; cell multiplication factor in the untreated control was 180 fold after 72 h; variation of the pH-values during the test was not more than 2 units
Conclusions:
Under the test conditions, the 72 h EbC50 of the test substance to the algae Scenedesmus subspicatus was 41.6 mg/L (nominal). The 72 h ErC50 was > 100 mg/L (nominal). The 72 h NOEC and LOEC were estimated to be 12.5 or 25 mg/L (nominal), respectively.
Executive summary:

A study was performed to assess the acute toxicity of the test substance to the algae Scenedesmus subspicatus according to OECD Guideline 201, EU Method C.3 and EPA OPPTS 850.5400.

Algae were exposed to the test substance at 0, 6.25, 12.5, 25, 50 and 100 mg/L in triplicate for 72 h in static test conditions at 21-25°C. Growth inhibition was determined at 0, 24, 48 and 72 h.

No analytical verification of doses was conducted. All values are expressed as nominal.

Under the test conditions, the 72 h EbC50 was 41.6 mg/L (nominal). The 72 h ErC50 was > 100 mg/L (nomila). The 72 h NOEC and LOEC were estimated to be 12.5 or 25 mg/L (nominal), respectively.

Description of key information

Key value for chemical safety assessment

EC50 for freshwater algae:
100 mg/L
EC10 or NOEC for freshwater algae:
30 mg/L

Additional information

A study was performed to assess the acute toxicity of amine synergist to the green algae Scenedesmus subspicatus according to OECD Guideline 201, EU Method C.3 and EPA OPPTS 850.5400. No analytical determination of dose levels was carried out as the substance hydrolyses rapidly. Results were presented based on nominal concentrations. Under the test conditions, the 72 h EbC50 of the test substance was 41.6 mg/L (nominal). The 72 h ErC50 was > 100 mg/L (nominal). The 72 h NOEC and LOEC were estimated to be 12.5 or 25 mg/L (nominal), respectively (Reuschenbach, 1999).