3-methyl-1,1-diphenylurea

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:

13.04.-24.04.2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

In the preliminary test the temperature is in the prescribed range (20 ± 2°C) during test, but with a variation greater than ± 1 °C (2.0 °C). In the preliminary test the variation was 2.2 °C. This deviation has not impact on the study.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Preparation of Sample Solutions: The samples of test solutions were prepared and delivered by Ecotoxicity group. The samples were analyzed on the day of delivery. The samples with nominal concentration 1 mg/L were analysed non-diluted. The samples with nominal concentration 100 and 58 mg/L were appropriate diluted (25 times) with UPW to the range of calibration curve. All samples were filtered through the syringe PTFE filter 0.45 μm before HPLC analyses.

Details on test solutions:

The stock solution of the test substance was prepared in the dilution water. 100 mg of the test substance was weighed into 1000 mL of the dilution water for the preliminary and definitive test. Because the test substance was poorly soluble for dilution was used ultrasound for 1 hours and stirring for 2 hours. The concentrations of solutions used in the preliminary and definitive test were obtained by dilution of the stock solution with dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM- Common name: Daphnia magna- Strain: Straus- Source: own laboratory breeding.- Age at study initiation: young Daphnia born in 24h- Method of breeding: aperiodic parthenogenesis - Feeding during test: noACCLIMATION- Acclimation period: 48h- Acclimation conditions: same as test- Type and amount of food: a mixture of algae- Health during acclimation: mortality control, healthy

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

Ca+Mg ions2.54 mmol/L preliminary study2.59 mmol/L definitive test

Test temperature:

20±2°C

pH:

7.8

Dissolved oxygen:

>3 mg/L

Nominal and measured concentrations:

100, 50, 10, 5, 1 mg/L preliminary test58, 32, 18, 10, 5.8, 3.2, 1.8, 1.0 mg/L definitive test

Details on test conditions:

TEST SYSTEM- Test vessel: glass beakers, 50 ml- Type: open- Aeration: withoutNumber of test animals: 20 for each concentration and control Number of replicates (per concentration): 2Number of test animals per replicate: 10Volume of test substance solution: 50 mL per 10 individualsDilution water was prepared just before the test by admixing 2.5 mL of stored solutions A, B, C and D into 1000 mL of deionized water.A.117.6 g CaCl2.2H20 in 1 L of deionized waterB.49.3 g MgSO4.7H2O in 1 L of deionized waterC.25.9 g NaHCO3 in 1 L of deionized waterD.2.3g KCl in 1 L of deionized water

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

20.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 18.3-22.6 mg/L

Results with reference substance (positive control):

Reference testThe sensitivity of the test species and correctness of test performance is periodically verifiedin six-month period by testing with the reference substance, potassium dichromate.The results of the verification test with K2Cr2O7, carried out in period from 15.04. to 17.04.2015 are the following:24 hour – EC50 = 1.95 mg.L-1(95% confidence limit: 1.75 – 2.15 mg.L-1)48 hour – EC50 = 0.86 mg.L-1(95% confidence limit: 0.70 – 1.02 mg.L-1)

Table No.: 1          Immobilisation of daphnia – preliminary test

Nominal concentration	mg·L^-1	100	50	10	5	1	C
Number of mobile animals	24 hours/1^stseries	10	9	10	10	10	10
Number of mobile animals	24 hours/2^ndseries	10	10	10	10	9	10
Number of mobile animals	24 hours/total	20	19	20	20	19	20
Immobilisation %	24 hours	0	5	0	0	5	0
Number of mobile animals	48 hours/1^stseries	2	1	2	5	9	9
Number of mobile animals	48 hours/2^ndseries	0	0	4	10	7	10
Number of mobile animals	48 hours/total	2	1	6	15	16	19
Immobilisation %	48 hours	90	95	70	25	20	5

Table No.: 5          Immobilisation of daphnia – definitive test

Nominal concentration	mg·L^-1	58	32	18	10	5.8	3.2	1.8	1.0	C
Number of mobile animals	24 hours/1^stseries	9	9	10	10	10	10	10	10	10
Number of mobile animals	24 hours/2^ndseries	10	10	9	10	10	9	10	10	9
Number of mobile animals	24 hours/total	19	19	19	20	20	19	20	20	19
Immobilisation %	24 hours	5	5	5	0	0	5	0	0	5
Number of mobile animals	48 hours/1^stseries	0	2	5	7	8	9	10	10	10
Number of mobile animals	48 hours/2^ndseries	1	4	6	8	8	9	10	10	9
Number of mobile animals	48 hours/total	1	6	11	15	16	18	20	20	19
Immobilisation %	48 hours	95	70	45	25	20	10	0	0	5

Validity criteria fulfilled:

yes

Conclusions:

24 hour–EC50 ˃ 100 mg•L-1 (nominal concentration)48 hour–EC50 = 20.4 mg.L-1 (nominal concentration)(95% confidence limit: 18.3 – 22.6 mg.L-1)

Executive summary:

The test substance, Akardit, was tested in acute immobilisation test on Daphnia magna.

The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test, Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008.

 

The preliminary test was performed in range of the test substance nominal concentrations
1 – 100 mg·L^-1. Based on toxicity of the test substance found in preliminary test,
the definitive test was performed in appropriate concentration range.

 

The analytical results showed that the test substance Akardit was sufficiently stable in dilution water at conditions of the test; therefore the definitive test was performed as static one.

The definitive test was performed in range of the test substance nominal concentrations
1 - 58 mg·L^-1. Samples for analytical determination were taken at the beginning and at the end of the test.

The nominal concentrations were used for all evaluations and results because, if evidence is available to demonstrate that the concentration of the test substance has been satisfactorily maintained within ± 20 per cent of the nominal or measured initial concentration throughout the test, then the results can be based on nominal or measured initial values.

 

Test results:

24 hour–EC₅₀˃ 100 mg·L^-1(nominalconcentration)

 

48 hour–EC₅₀= 20.4 mg·L^-1(nominalconcentration)

(95% confidence limit: 18.3 – 22.6 mg·L^-1)

 

Description of key information

Akardit, was tested in acute immobilisation test on Daphnia magna. The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test, Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008.

Only one study available.

GLP study.

Klimish score 1.

The analytical results showed that the test substance Akardit was stable in dilution water at conditions of the test, therefore the nominal concentrations were used for all evaluations and results.

The value EC50 (48h) for daphnia magna was used for C&L and for Chemical Safety Assessment.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

20.4 mg/L