Urea, polymer with ethanedial

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April 2, 2013 - April 4, 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 197.5, 296.3, 444.4, 666.7 and 1000 mg a.i./L.- Sampling method: To avoid incorrect TOC data (because of the test system) a special sampling method was used: parallel with the beakers containing animals, additional beakers containing no animals were run during the test. Analytical samples were taken from the flasks containing no animals at the beginning and end of the renewal periods. Three replicate were analysed from each diluted analytical samples.- Sample storage conditions before analysis: The samples were analysed immediately after sampling or immediately after dilution of the samples.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances): Active ingredient content of the test substance (46.3 % in water solution) was taken into account in order to prepare the appropriate test solutions, therefore an amount of 2160 mg test substance was diluted in 1000 mL ISO medium (stock solution concentration: 1000 mg a.i./L). The test solutions were prepared by appropriate dilution of this stock solution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM- Strain: Daphnia magna- Source: National Institute of Public Health 1097 Budapest Gyáli u. 2-6. Hungary- Age at study initiation (mean and range, SD): Less than 24 h old- Feeding during test: NoACCLIMATION: There was no acclimatization because the water used was similar to the culture water.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

249 mg/L (as CaCO3)

Test temperature:

20.5 – 20.8 °C

pH:

7.55 – 7.96

Dissolved oxygen:

8.3 – 8.6 mg/L

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 197.5, 296.3, 444.4, 666.7 and 1000 mg a.i./L.Measured concentrations (geometrical mean): 0 (control), 204.0; 311.0; 460.0; 695.3 and 1020.9 mg a.i./L.

Details on test conditions:

TEST SYSTEM- Test vessel: Beaker - Material, size, headspace, fill volume: glass beaker with a volume of 50 mL- Aeration: No- No. of organisms per vessel: 5- No. of vessels per concentration (replicates): 4- No. of vessels per control (replicates): 4TEST MEDIUM / WATER PARAMETERS- Source/preparation of dilution water: Reconstituted water (ISO medium, according to OECD 202)OTHER TEST CONDITIONS- Adjustment of pH: No- Photoperiod: 16-hour light and 8-hour dark cycle- Light intensity: No dataEFFECT PARAMETERS MEASURED (with observation intervals if applicable): The immobility or mortality of the Daphnia was determined by visual observation 24 and 48 hours after the start of the test. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker are considered to be immobile.TEST CONCENTRATIONS- Spacing factor for test concentrations: 1.5- Range finding study: Two concentration range-finding tests were conducted to determine the approximate toxicity of the test item so that appropriate test concentrations can be selected for use in the definitive test to get the EC50 value of the test substance.- Test concentrations:Test 1: 0, 0.1, 1, 10 and 100 mg/L (10 animals per dose, semi-static, 48 hours)Test 2: 0, 125, 250, 500 and 1000 mg/L (10 animals per dose, semi-static, 48 hours)- Results used to determine the conditions for the definitive study:Test 1: 0, 0, 0, 0 and 0% of immobilisation respectivelyTest 2: 0, 0, 0, 40 and 100% of immobilisation respectively

Reference substance (positive control):

yes

Remarks:

(at least twice per year by CitoxLAB)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

466.77 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 95 % CL: 431.06-527.72 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

296.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

Other adverse effects could not be observed during the experiment.

Results with reference substance (positive control):

Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions. The date of the last study (Study Code: 13/019-023DA) with reference item Potassium dichromate (batch no.: 0769128) is: 07-08 February 2013. The 24h EC50: 0.89 mg/L, (95 % confidence limits: 0.72 – 1.02 mg/L)

Reported statistics and error estimates:

The 24 and 48 hours EC50 values were determined by Probit analysis with 95 % confidence limits using SPSS PC+ software. For the determination of the LOEC and NOEC, the immobilization at the test concentrations was tested on significant differences to the control values by Dunnett’s Test using TOXSTAT software. The 48 hours EC100 values were determined directly from the raw data.

The 24h EC50 value: 682.51 mg a.i./L (95% confidence limits: 610.67 -764.90 mg a.i./L)

The 48h EC50 value: 466.77 mg a.i./L (95 % confidence limits: 431.06 -527.72 mg a.i./L)

The 48h EC100 value: 666.7 mg a.i./L

The 48h No-Observed Effect Concentration (NOEC): 296.3 mg a.i./L

The 48h Lowest Observed Effect Concentration (LOEC): 444.4 mg a.i./L

DEFINITIVE TEST:

Concentration	Number of treated animals	Immobilised animals
		24 hours		48 hours
Nominal (mg a.i./L)		number	%	number	%
Control	20	0	0	0	0
197.5	20	0	0	0	0
296.3	20	0	0	0	0
444.4	20	2	10	7*	35
666.7	20	6*	30	20*	100
1000	20	20*	100	20*	100

*: Statistically significantly different compared to the control values (Dunnett's Test; α = 0.05)

As the measured concentration deviated more than 20 per cent from the nominal in one case, biological results were based on the measured geometric mean concentrations.

Validity criteria fulfilled:

yes

Remarks:

(no immobilized animal in the control, dissolved oxygen concentration at the end > 3 mg/L)

Conclusions:

The EC50 (based on mobility) of test item in Daphnia magna at 48 h exposure period was 466.77 mg a.i./L and the NOEC was determined to be 296.3 mg a.i./L.

Executive summary:

An acute immobilisation test on Daphnia magna was performed in accordance with EU method C.2. and OECD Guideline 202. Based on the results obtained in the preliminary range-finding test, the following nominal concentrations were tested: 0 (control) 197.5, 296.3, 444.4, 666.7 and 1000 mg/L (separation factor of 1.5). Test concentrations were analytically determined at the beginning and at the end of the test and did not deviate more than 20%. Twenty animals per dose, divided into four groups (glass baker) of five animals each were exposed to the test item for 48 hours under semi-static conditions. All validity criteria were met. The 48h EC50 was determined to be 466.77 mg a.i./L and the 48h-NOEC was determined to be 296.3 mg a.i./L, both based on mobility.

Description of key information

Key study: Test method OECD 202. GLP study. The 48h EC50 was determined to be 466.77 mg a.i./L and the 48h-NOEC was determined to be 296.3 mg a.i./L, both based on mobility.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

466.77 mg/L

Additional information

Key study: An acute immobilisation test on Daphnia magna was performed in accordance with EU method C.2. and OECD Guideline 202. Twenty animals per dose were exposed up to 1000 mg a.i./L the test item for 48 hours under semi-static conditions. The 48h EC50 was determined to be 466.77 mg a.i./L and the 48h-NOEC was determined to be 296.3 mg a.i./L, both based on mobility.