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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:
2008.05.20-2008.05.23
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
GLP compliance:
yes
Remarks:
The chemical analysis was carried out as accredited analysis but not in compliance with the GLP principles.
Specific details on test material used for the study:
Batch no. 512051
Manufacturing data: December 2005
Origin: Dr. Straetmans Chemische Produkte GmbH, Germany
Form: Almost colourless viscous liquid
Details on test solutions:
The test product is not soluble but dispersible in water.
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Clone: NIVA, CHL 1
Test type:
static
Water media type:
other: ISO-medium
Total exposure duration:
72 h
Test temperature:
23.3 °C ± 0.1 °C
pH:
pH 8.2 ± 0.2
Nominal and measured concentrations:
Nominal concentrations: 0 (control); 2.0; 5.0; 10; 20; 50; 100 and 200 mg/L.
Details on test conditions:
During 72 hours, the growth of the algae was followed by measuring the fluorescence at the beginning of the test and every 24 hours.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate (Merck 4864)
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
20 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
56.7 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.:
10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Results with reference substance (positive control):
The reference test was performed at the following concentrations: 0 (control); 0.10; 0.20; 0.40; 0.70; 1.0; 1.4 and 2.0 mg/L.
NOEC for potassium dichromate was 0.1 mg/L. EC 10 was 0.34 mg/L and EC50 was 0.75 mg/L based on nominal concentrations.
Reported statistics and error estimates:
The EC values were calculated by use of the computer program TOXEDO. The highest test concentration without significant effect was estimated by use of variance analysis according to Dunnett's procedure.
Validity criteria fulfilled:
yes
Conclusions:
No significant effect was observed on the growth of Pseudokirchneriella subcapitata at conterations from 2.0-10 mg/L. Significant inhibition of the growth of Pseudokirchneriella subcapitata was observed at concentrations from 20 -200 mg/L.
NOEC for the growth was 10 mg/L. EC 10 was 20.0 (18.6 - 21.3) mg/L and EC50 was 56.7 (54.6 - 59.0) mg/L based on nominal concentrations.
Executive summary:

The aquatic toxicity of Dermosoft DGMC to algae was studied in a test performed according to the OECD guideline no. 201 and following GLP. The test was carried out as a 72 -hour test, where the growth of the algae was followed by measuring the fluorescence at the beginning of the test and every 24 hours.

Dermosoft DGMC was tested in the nominal concentrations: 0 (control); 2.0; 5.0; 10; 20; 50; 100 and 200 mg/L.

The chemical analyses of NVOC measured in test concentrations relevant to calculation of the EC values (20-200 mg/L) showed a recovery of 79-90% of the initial concentration, i.e. >80%. The statistical calculations were thus made on basis of the nominal concentrations.

No significant effect was observed on the growth of Pseudokirchneriella subcapitata at conterations from 2.0-10 mg/L. Significant inhibition of the growth of Pseudokirchneriella subcapitata was observed at concentrations from 20 -200 mg/L.

NOEC for the growth was 10 mg/L. EC 10 was 20.0 (18.6 - 21.3) mg/L and EC50 was 56.7 (54.6 - 59.0) mg/L based on nominal concentrations.

Description of key information

The results from the 72 -hour toxicity study showed that the NOEC for the algae growth was 10 mg/L. EC 10 was 20.0 (18.6 - 21.3) mg/L and EC50 was 56.7 (54.6 - 59.0) mg/L based on nominal concentrations.

Key value for chemical safety assessment

EC50 for freshwater algae:
56.7 mg/L
EC10 or NOEC for freshwater algae:
10 mg/L

Additional information