Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Qualifier:
according to guideline
Guideline:
other: DIN 38412 Part 9
GLP compliance:
no
Analytical monitoring:
no
Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
- Scenedesmus subspicatus CHODAT SAG 86.81
- Supplier: SAG (Collection of algal cultures in Goettingen, GER)
Test type:
static
Water media type:
freshwater
Limit test:
no
pH:
Range over start and end of test: 6.76 - 9.78
Nominal and measured concentrations:
- Nominal concentrations: 7.812, 15.625, 32.25, 62.5, 125, 250 and 500 mg/L
Details on test conditions:
Test conditions:
- Dilution water chemistry: OECD guideline 201.
- Test temperature: 293 K (approx. 20°C)
- Exposure vessels: 10 mL
- Light conditions: no data
- Number of Replicates: 4
- Initial cell number: 10000 cells/mL

Measurements:
- pH values: After 0 and 72 hours
- in vivo chlorophyll-a-fluorescence after 0, 24, 48, 72 and 96 hours.
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
83.7 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
51.4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
147.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate

ADDITIONAL REPORTED EFFECT CONCENTRATIONS

- ErC20 (24h) 57.2 mg/L
- ErC50 (24h) 116.8 mg/L
- ErC90 (24h) -
- ErC20 (48h) 64.5 mg/L
- ErC50 (48h) 96.2 mg/L
- ErC90 (48h) -

Description of key information

The 72 -h ErC50 is 84 mg/L in freshwater algae (D. subspicatus).

Key value for chemical safety assessment

Additional information

The toxicity towards freshwater algae was determined in a study according to DIN 38412 L9 (not GLP-compliant). In this study, exponentially growing freshwater alga (Desmodesmus subspicatus) were exposed to nominal test substance concentrations of 7.812, 15.625, 32.25, 62.5, 125,  250 and 500 mg/L under static conditions. At the start of the test and after 24, 48, 72 and 96 hours exposure duration, the algae were scored for number of cells. Based on these findings, the 72-h EC50 values for growth rate was determined at 83.7 mg/L. The EC20 and EC90 were determined at 51.4 and 147.3 mg/L, respectively.

Categories Display