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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
Reliability:
1 (reliable without restriction)
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Specific details on test material used for the study:
Purity: >90%
Batch: 900150909STG115
Analytical monitoring:
yes
Details on sampling:
The concentration and stability of the test item were verified by chemicasl analysis at 0 and 72 hours.
Vehicle:
yes
Details on test solutions:
A nominal amount of test item was dissolved in dimethylformamide.
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
P. subcapitata strain CCAP 278/4 were used for the test. The cultures were obtained from the Culture Collection of Alae and Protozoa (CCAP), SAMS Research Services Ltd, Scottish Marine Institue, Oban, Argyll, Scotland.
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h
Test temperature:
Test temperature was maintained at 24 +/- 1 deg C.
pH:
The pH was measured throughout the test and teh pH ranged from 7.7-8.2
Nominal and measured concentrations:
A nominal amount of the test item (100mg/L) was dissolved in dimethylformamide and the volume adjusted to 10mL to give a 100 mg/10mL solvent stock solution. 100% v/v of this solution was used during the testing. Chemical analysis of this showed measured test concentrations of 0.10 and 0.11 mg/L.
Details on test conditions:
100mL of test solution was put into 250 mL glass conical flasks. Six replicates were used for the control, solvent control and 100%v/v treatment fourp. Flasks were plugged with polyurethane foam bungs and incubated at 24+/- 1 deg C under continuous illumination provided by wartm white lighting and constantly shaken for 2 hours.
Reference substance (positive control):
yes
Remarks:
potassium dichromate
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.1 mg/L
Nominal / measured:
meas. (geom. mean)
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 0.1 mg/L
Nominal / measured:
meas. (geom. mean)
Basis for effect:
growth rate
Details on results:
No toxic effects were seen at the highest obtainable concentration.
Results with reference substance (positive control):
A positive control used potassium dichromate as the reference item at concentrations of 0.25, 0.5, 1.0, 2.0, 4.0 mg/L. Exposure conditions and data evaluation for the positive control. The following results were obtained EC50 1 mg/L and a NOEC of 0.25 mg/L.
Validity criteria fulfilled:
yes
Conclusions:
Analysis of the 100% v/v test preparation at 0 and 72 hours showed measured test concentrations of 0.10 and 0.11 mg/L. Exposure of P. subcapitata to the test item gave EC50 calues of greater than 0.10mg/L and a NOEC of > 0.10mg/L. No toxic effects were seen at saturation.
Executive summary:

Testing was carried out following the methods outlined in the OECD 201 guideline. Analysis of the 100% v/v test preparation at 0 and 72 hours showed measured test concentrations of 0.10 and 0.11 mg/L. Exposure of P. subcapitata to the test item gave EC50 calues of > 0.10mg/L and a NOEC of > 0.10mg/L. No toxic effects were seen at saturation.

Description of key information

Testing was carried out following the methods outlined in the OECD 201 guideline. Analysis of the 100% v/v test preparation at 0 and 72 hours showed measured test concentrations of 0.10 and 0.11 mg/L. Exposure of P. subcapitata to the test item gave EC50 values of > 0.10mg/L and a NOEC of > 0.10mg/L. No toxic effects were seen at saturation.

Key value for chemical safety assessment

EC50 for freshwater algae:
0.1 mg/L
EC10 or NOEC for freshwater algae:
0.1 mg/L

Additional information

The available studies on the acute and chronic toxicity of IDDPP towards algae show no effects below the water solubility.Values are well above the water solubility (11.2 ug/l) of the substance, IDDPP can not be classified as toxic to the environment.