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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008-09-12 - 2008-09-25
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The GLP study was conducted according to an internationally accepted guideline. All study parameters are based on the specific guideline.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h

Test conditions

Test temperature:
22.0-22.5 °C
pH:
7.4-7.9
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
70.6 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
< 53 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
66 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
72 hour - EbC50 = 70.6 mg/L
72 hour - ErC50 > 100 mg/L
72 hour - NOECb < 53 mg/L
72 hour - NOECr = 66 mg/L

Executive summary:

The test substance, Weikoform (Urea, reaction products with formaldehyde), was tested for growth inhibition on algae Desmodesmus subspicatus. The test was performed according to EU Method C.3 - Algal Inhibition Test, Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008. The preliminary test was performed in range of test substance nominal concentrations 1-100 mg/L. The analytical results showed, that the test substance Weikoform (Urea, reaction products with formaldehyde) was stable in the highest test concentrations (100 mg/L). In the lowest test concentrations (1 mg/L) the analytical results do not correspond solution dosing, but a reason was not found. Based on the toxicity of the test substance found in preliminary test, the full test was performed in appropriate concentration range. The full test was performed in range of test substance nominal concentrations 53 - 100 mg/L. Samples for analytical determination were taken at the beginning, after 24 hours and at the end of the test. The analytical results showed that the test substance Weikoform (Urea, reaction products with formaldehyde) was stable in test medium in conditions of the test; therefore the nominal concentrations were used for all evaluations and results.

Results:

72 hour - EbC50 = 70.6 mg/L

72 hour - ErC50 > 100 mg/L

72 hour - NOECb < 53 mg/l

72 hour - NOECr = 66 mg/L