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

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

8 November 1999 - 3 May 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Stable in water for at least 96 hours.

Analytical monitoring:

yes

Details on sampling:

Samples were taken from all test concentrations and the control according to the schedule below.
Frequency: at t=0 and t=96 h
Volume: 10 mL from the approximate centre of the test vessels
Storage: Samples were stored in a deep-freezer until analysis.

Additionally, reserve samples of 10 mL were taken from all test solutions for possible analysis. These samples were stored in a freezer for a maximum of three months after delivery of the draft report, for possible additional analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
- Method: the test substance was not completely soluble in test medium at 100 mg/L. The actual water solubility was < 9 µg/L (determined in an earlier study by NOTOX). Preperation of test solutions starteds with two seperate dispersions of 100 mg/L. Ultra sonic treatment was applied to disperse the test substance in the test medium. The dispersions were stirred for 3 days prior to testing. One dispersion was filtered through a paper filter (5 µm). Before filtration, the dispersions were milky with a test substance layer at the surface. After filtration, the solution was clear and colourless.
- Controls: test medium without test item or other additives (blank-control)

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Carp
- Strain: Linnaeus, 1758
- Source: Zodiac, proefacc, "De Haar Vissen", L.U. Wageningen, the Netherlands
- Length at study initiation (mean): 2.55 +/- 0.08 cm
- Weight at study initiation (mean): 0.42 +/- 0.07 g
- Feeding during the test: no feeding from 48 hours prior to the test and during the total test period.

ACCLIMATION
- Acclimation period: at least 12 days after delivery
- Acclimation conditions: ISO medium, same as test medium
- Type and amount of food during acclimation: daily feeding with Trouvit
- Health during acclimation: mortality observed during the seven days prior to the start of the test was less than 5%.

BREEDING:
- Method of breeding: F1 from a single parent-pair bred in UV-treated water.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

250 mg CaCO3/L

Test temperature:

20.3 - 21.5 °C in all test vessels throughout the test period

pH:

7.6 - 8.1

Dissolved oxygen:

6.7 - 9.3 mg O2/L

Nominal and measured concentrations:

Nominal test concentrations: 100 mg/L filtered and 100 mg/L unfiltered
Measured concentrations at t=0: 0.260 mg/L (filtered sample) and 19.3 mg/L (unfiltered sample)
Measured concentrations after 96 hours: 0.047 mg/L (filtered sample) and 1.46 mg/L (unfiltered sample).
For details on analytical results, see attached background material ('analytical results'). Effect concentrations were based on the geometric mean of the test solution prepared at a loading rate of 100 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 8 litres, all-glass, open, fill volume: 5 litres
- Aeration: no
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1 for the filtered 100 mg/L solution, 1 for the unfiltered 100 mg/L solution
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.6 g fish/Litre

TEST MEDIUM / WATER PARAMETERS
- Standard medium used: yes, ISO medium
- Source of dilution water: Milli-Ro water (tap water purified by reversed osmosis)
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours, daily

EFFECT PARAMETERS MEASURED: mortality and sublethal effects were measured at 3, 24, 48, 72 and 96 hours.
- Additional measurements: dissolved oxygen content, pH daily in all vessels, beginning at day 0; temperature daily in one control vessel, beginning at the start of the test.

Reference substance (positive control):

yes

Remarks:

pentachlorophenol (January 2000)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.11 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mortality (fish)

Remarks on result:

other: Result is based on geometric mean measured concentration of the filtered sample prepared at a loading rate of 100 mg/L (geometric mean of 0.260 mg/L and 0.05 mg/L).

Details on results:

- No biological, behavioural or other abnormalities were observed and no mortality occured during the exposure period.
- Effect concentrations exceeding solubility of substance in test medium: yes

Individual pH, temperature and dissolved oxygen values remained within acceptable limits throughout the duration of the study.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Mortality 0% at 0.10 mg/L and 100% at 0.22 mg/L
- LC50: 0.14 mg/L, 95% confidence level: 0.13 - 0.18 mg/L
- Other: results fell within the historical range but was relatively low, therefore te carp originating from this batch can be considered as relatively sensative to toxic substances.

Validity criteria fulfilled:

yes

Remarks:

For details on validity criteria see 'overall remarks' section.

Conclusions:

No lethal or sublethal effects were seen at a test solution with a loading rate of 100 mg/L, the LC50 was > 0.11 mg/L based on the geometric mean measured concentration.

Executive summary:

In a 96 -h acute toxicity study conducted according to OECD guideline 203 and GLP principles, carp (Cyprinus carpio) were exposed to the test substance in a limit test under static conditions at a nominal concentration of 100 mg/L. The test solution was treated with ultra sonic and stirred for three days to ensure maximum dillution of the test substance in test medium. Seven carps were exposed to a filtered and an unfiltered dispersion sample during the test period in all-glass, open vessels. Analysis of the samples taken from the test solutions showed measured concentrations of 0.26 mg/L (filtered sample) and 19.3 mg/L (unfiltered sample) at t=0 h and 0.05 mg/L (filtered sample) and 1.46 mg/L (unfiltered sample) at t=96 h. Effect concentrations were therefore based on the geometric mean of measured concentrations of the filtered samples (0.11 mg/L). No mortality or other effects were seen in both the filtered and unfiltered samples at a nominal concentration of 100 mg/L. The 96h-LC50 exceeded 0.11 mg/L. The study is considered to be reliable without restrictions.

Description of key information

A reliable study, performed according to OECD guideline 203 and GLP principles, resulted in an LC50 >0.11 mg/L, the geometric mean measured concentration. No effects were seen.

Additional information

In a 96 -h acute toxicity study conducted according to OECD guideline 203 and GLP principles, carp (Cyprinus carpio) were exposed to the test substance in a limit test under static conditions at a nominal concentration of 100 mg/L. The test solution was treated with ultra sonic and stirred for three days to ensure maximum dilution of the test substance in test medium. Seven carps were exposed to a filtered and an unfiltered dispersion sample during the test period in all-glass, open vessels. Analysis of the samples taken from the test solutions showed measured concentrations of 0.26 mg/L (filtered sample) and 19.3 mg/L (unfiltered sample) at t=0 h and 0.05 mg/L (filtered sample) and 1.46 mg/L (unfiltered sample) at t=96 h. Effect concentrations were therefore based on the geometric mean of measured concentrations of the filtered samples (0.11 mg/L). No mortality or other effects were seen in both the filtered and unfiltered samples at a nominal concentration of 100 mg/L. The 96h-LC50 exceeded 0.11 mg/L. The study is considered to be reliable without restrictions.