Urea, reaction products with formaldehyde

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

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Urea, reaction products with formaldehyde

EC Number:

271-898-1

EC Name:

Urea, reaction products with formaldehyde

Cas Number:

68611-64-3

Molecular formula:

not available

IUPAC Name:

Urea, reaction products with formaldehyde

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 concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

70.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 53 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 4

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