N,N''-(methylenedi-4,1-phenylene)bis[N'-octyl]urea

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:

22 October 2002 - 24 October 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The test was conducted according to OECD Guideline 202 and in compliance with GLP. The stock solutions were prepared by agitation for 24 hours and then filtered twice (porosity of 4-7 µm and then of 0.45 µm). The filtered solution was then further used to prepare the test solutions. The measured concentrations of test substance in these solutions were below the limit of quantification (0.5 mg/L) at all measurement times. Based on the fact that the substance is highly insoluble in water (water solubility 4 µg/L) and has a high adsorptive potential (Koc of one constituent 4.8 and of the two other constituents> 5.6), it can only be concluded that the LC50 > maximum solubility of the test substance in medium

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)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 1000 mg/L
- Sampling method: samples taken at the begining of the test, at T24 and T48 h.
- Sample storage conditions before analysis: at -20 °C

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:stirring the test item in water for 24 h
- Evidence of undissolved material (e.g. precipitate, surface film, etc): the solution was filtered through a filter with 4-7 µm porosity, followed by filtration through 0.45 µm

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus-clone 5
- Source: Centra Technique du Bois et de l'Ameublement, Paris, France
- Age at study initiation (mean and range, SD): 6-24 h old
- Feeding during test: none


ACCLIMATION
- Acclimation period: from birth until use in the test
- Acclimation conditions (same as test or not): yes
- Type and amount of food: algal Scenedesmus subspicatus, 0.1-0.2 mg C/Daphnia/day
- Feeding frequency: daily
- Health during acclimation (any mortality observed):not reported

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

control t0 and t 48h: 289 and 272 mg/L

Test temperature:

control: 19.8 °C
limit test: 19.7 °C

pH:

control t0 and t48h: 7.83 and 8.34
limit test: t0 and t 48h: 8.07 and 8.33

Dissolved oxygen:

control t0 and t48h: 9 and 8.2 mg/L
limit test: t0 and t 48h: 8.1 and 8.4 mg/L

Nominal and measured concentrations:

Limit test nominal: 0 and 1000 mg/L
Limit test measured: < 0.5 mg/L (< LOQ)
Range finding test nominal: 1; 10 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker
- Type: not reported
- Material, size, headspace, fill volume: not reported
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates):4
-Loading: one animal/10 mL culture water

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted M4
- Total organic carbon: not reported
- Particulate matter: not reported
- Metals: not reported
- Pesticides: not reported
- Chlorine: not reported
- Ca/mg ratio: 4:1
- Conductivity: not reported
- Culture medium different from test medium: no
- Intervals of water quality measurement: at the begining and end of the test

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light and 8 h dark
- Light intensity: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EL50 (mobility)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10 (range finding)
- Range finding study yes
- Test concentrations: 1, 10 and 100 mg/L (range finding)
-Limit test: 1000 mg/L

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC50

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: The LC50 was > maximum soluble concentration of test substance in medium.

Details on results:

- Behavioural abnormalities: no
- Observations on body length and weight: not reported
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: not reported
- Effect concentrations exceeding solubility of substance in test medium: no
- analytics: measured concentrations < 0.5 mg/L (< LOQ)

The authors concluded that the 96h LC50 was > 1000 mg/L (initial loading rate). The French Authorities reported the 96h LC50 as > 4.38 µg/L (water solubility limit).

Validity criteria fulfilled:

yes

Conclusions:

No effects were observed in the limit test, conducted with the filtrate of a 1000 mg/L loading rate. The measured concentrations of test substance in these solutions were below the limit of quantification (0.5 mg/L) at all measurement times. Based on the fact that the substance is highly insoluble in water (4 µg/L) and has a high adsorptive potential (Koc of one constituent 4.8 and of the two other constituents> 5.6), it can only be concluded that the EC50 > maximum solubility of the test substance in medium.
The Competent Authority of France concluded in 2003 that the EC50 for Daphnia magna should be >4.38 µg/L (the water solubility limit).

Executive summary:

The acute toxicity of KY-EU to Daphnia magna was examined in a static system according to OECD guideline 202 and GLP.

Daphnids were exposed to a WAF that was prepared at a loading rate of 1000 mg/L by stirring for 24h, followed by filtration through a filter with 4-7 µm porosity, and a filter with 0.45 µm porosity, subsequently. Samples were taken at the beginning of the test, at t = 24 and t = 48 h and stored at -20°C until analysis. Samples were analysed with HPLC-UV. The analysis was based on only one component out of 3 of KY-EU.

 

No effects of the test item to daphnia were observed.

 

The measured concentrations of test substance in these solutions were below the limit of quantification (0.5 mg/L) at all measurement times. Based on the fact that the substance is highly insoluble in water (4 µg/L) and has a high adsorptive potential (Koc of one constituent 4.8 and of the two other constituents> 5.6), it can only be concluded that the EC50 > maximum solubility of the test substance in medium.

Description of key information

No effects were observed in the limit test, conducted with the filtrate of a 1000 mg/L loading rate. The measured concentrations of test substance in these solutions were below the limit of quantification (0.5 mg/L) at all measurement times. Based on the fact that the substance is highly insoluble in water (4 µg/L) and has a high adsorptive potential (Koc of one constituent 4.8 and of the two other constituents> 5.6), it can only be concluded that the EC50 > maximum solubility of the test substance in medium.

Additional information

Daphnids were exposed to a WAF that was prepared at a loading rate of 1000 mg/L by stirring for 24h, followed by filtration through a filter with 4-7 µm porosity, and a filter with 0.45 µm porosity, subsequently. Samples were taken at the begining of the test, at t = 24 and t = 48 h and stored at -20°C until analysis. Samples were analysed with HPLC-UV. The analysis was based on only one component out of 3 of KY-EU.

 

No effects of the test item to daphnia were observed.

 

The measured concentrations of test substance in these solutions were below the limit of quantification (0.5 mg/L) at all measurement times. Based on the fact that the substance is highly insoluble in water (4 µg/L) and has a high adsorptive potential (Koc of one constituent 4.8 and of the two other constituents> 5.6), it can only be concluded that the EC50 > maximum solubility of the test substance in medium.