N,N’-di[3-(p-toluene sulfonyl)oxy]phenyl 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

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:

July 17, 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Fish, Acute Toxicity Test stipulated in Testing Method for New Chemical Substances of Japanese Chemical Substances Control Law

Version / remarks:

July 1, 2019

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD Guidance Document No. 23

Version / remarks:

February 2019
Guidance Document on Aqueous-phase Aquatic Toxicity Testing of Difficult Test Chemicals

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: single concentration (nominal concentration: 100 mg/L)
- Sampling method: Solution sampled separately from the preparation container (at start of exposure); mixed solution was taken out with equal volumes from the middle layer of the test solution in the test vessels in each test level (at the end of exposure)
- Sample storage conditions before analysis: samples were analysed straightaway after collection.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A saturated solution was prepared. 0.28g test item and 2800mL dilution water were mixed to produce the test concentration 100 mg/L and stirred by a magnetic stirrer for 48h to prepare the test solution. The test solution was divided into each test vessel.
- Controls: Dilution water (negative control) prepared using the same method as the test solution but no test item added
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): No used; not applicable
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): not applicable
- Test concentration separation factor: not applicable (limit test)
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): yes: white suspension, precipitation and insoluble matter were observed.
- Other relevant information: undissolved test item had no physical effect on the test organisms

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name: Japaese Medaka
- Source: in-house
- Age at study initiation (mean and range, SD): 3 months
- Length at study initiation (length definition, mean, range and SD): 2.0 cm +/- 1cm

ACCLIMATION
- Acclimation period: 59 days
- Acclimation conditions (same as test or not): Flow-through
- Type and amount of food during acclimation: KYORIN, amount corresponding to 3% of body weight
- Feeding frequency during acclimation: daily. withdrawn 24 hours before start of exposure
- Health during acclimation (any mortality observed): 0% mortality observed 7 days before start of exposure

FEEDING DURING TEST (as applicable): not fed during test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Remarks on exposure duration:

As recommended in the guideline

Post exposure observation period:

Not applicable

Test temperature:

24 +/1 °C

pH:

7.8 - 8.0

Dissolved oxygen:

8.0 - 8.2 mg/L at start of exposure
8.3 mg/L at end of exposure

Nominal and measured concentrations:

Nominal: 100 mg/L
Measured: 0.000618 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 3L glass tank, transparent plastic lid
- Type (delete if not applicable): open
- Material, size, headspace, fill volume:
- Aeration: yes
- Renewal rate of test solution (frequency/flow rate): not renewed
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water, aerated sufficiently and temperature controlled
- Total organic carbon: <0.5 mg/L
- Particulate matter: <1 mg/L
- Metals: - Pesticides: - Chlorine: <0.02 mg/L
- Alkalinity: 39 mg/L
- Ca/mg ratio: 44 mg/L

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: Room light, 16-hour light, 8 hours dark
- Light intensity: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and visible abnormality were observed at 3, 24, 48, 72 and 96 hours after exposure. A fish was considered dead when the observable motion (motion of the month or opercula, etc.) was not observed and touching of the caudal peduncle with a glass rod caused no reaction.

- Range finding study
- Test concentrations: 100 mg/L
- Results used to determine the conditions for the definitive study: yes - no mortality

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks on result:

other: No mortality or abnormal behaviour was observed during the test.

Details on results:

- Other abnormalities: None
- Observations on body length and weight: No abnormal findings
- Mortality of control: None
- Other adverse effects control: None
- Effect concentrations exceeding solubility of substance in test medium: No effects observed in study.

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

None.

Sublethal observations / clinical signs:

Table 1: Cumulative mortality

Measured concentration^a (mg/L)	Cumulative mortality (%)
	3 hours	24 hours	48 hours	72 hours	96 hours
Control	0	0	0	0	0
0.000618	0	0	0	0	0

^aTime-weighted mean of the measured concentrations (also expressed as measured concentration in the following tables)

Table 2: Observed abnormal response

Measured concentration^a (mg/L)	Result of observation
	3 hours	24 hours	48 hours	72 hours	96 hours
Control	N	N	N	N	N
0.000618	N	N	N	N	N

N:  Normal (no abnormal response) – all fish 7/7

 

 

Table 3: EC50 values to Medaka

Exposure duration	LC50 (mg/L)
24 hours	>0.000618
48 hours	>0.000618
72 hours	>0.000618
96 hours	>0.000618

 

Table 4: Measured concentration of the test item in test solution

Nominal concentration (mg/L)	Measured concentration (mg/L) (percentage of measured concentration versus that at the start %)
	At the start	At the end	Time-weighted average mean
Control	<LOQ	<LOQ	-
100	0.0000698	0.00220 (3160)	0.000618

LOQ = 0.0002 mg/L

The time weighted mean is calculated by the following calculation:

[96 (C₀-C₉₆)/(lnC₀-lnC₉₆]/96

C_n: the measured concentration at n hours

lnC_n: the natural logarithm of C_n

Validity criteria fulfilled:

yes

Remarks:

No mortality within control Dissolved oxygen concentration was >60% of air saturation value at the water temperature throughout the exposure duration

Conclusions:

No mortality or abnormal behaviour was observed during the limit test. The 96h LC50 was calculated as >0.000618 mg/L greater than the solubility of the test item in the test water.

Description of key information

In a study conducted in accordance with OECD Guideline 203 on Japanese Medeka, the 96h LC50 >100 mg/L (nominal) was reported.  Based on measured concentrations, no mortality or abnormal behaviour was observed up to the limit of solubility of the test item (TWA measured with analytical verification at 0.000618 mg/L). 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

> 100 mg/L