N,N'-naphthalene-1,5-diylbis[4-[(2,3-dichlorophenyl)azo]-3-hydroxynaphthalene-2-carboxamide]

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:

2011-12-19 to 2011-12-23

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of the saturated solution: A stock solution (1 mg/L test item was weighed out) was prepared with dilution water. Weighing of the test item for day 0 and 1 was carried out 72 h prior to test start and stored in the dark at room temperature until preparation of the saturated solution. Weighing of the test item for day 2 and 3 was carried out after 0 and 24 h of the study, respectively.The stock solution was stirred for 48 hours with a magnetic stirrer. The undissolved particles were removed by membrane filtration (membrane filter 0.45 µm, RC, MACHEREY-NAGEL). The centrifugation for 20 min at 10000 g was performed at day 0. No pellet was generated, so the procedure was declared insufficient. On the following days only membrane filtration was used.
- Eluate: Tap water of local origin was used for holding and testing. The water was filtered on activated charcoal and aerated for at least 24 h to remove possible chlorine.
- Controls: 7 fish in dilution water (without test item) were tested under the same test conditions as the test replicates.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: All fish used in the test were gained at DR.NOACK-LABORATORIEN from a single brood stock. (supplier: Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz, An der Scharlake 39, D-31135 Hildesheim)
- Length at study initiation: Average body length: 2.43 cm
- Weight at study initiation: Average body weight: 0.284 g
- Method of breeding: at the test facility at 23 +/- 2 °C and diffuse light (0.1 - 10 µmol photons x m-2 x s-1, natural photoperiod). The water was changed at least once per week. The dissolved oxygen concentration was more than 80 % of the air saturation value.
- Feeding during test: No feeding during test

ACCLIMATION
- Acclimation period: at least 12 days of acclimatisation and mortality < 5 % within these days before the study starts
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food: 4 % of the fish body weight per feeding day. The test fish were not fed 24 h before the test started. Food: Sera Vipan; SERA GMBH, D-52518 Heinsberg
- Feeding frequency: 3 times per week.
- Health during acclimation (any mortality observed): No mortality observed, no disease treatments were administered throughout holding and testing.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

Total Hardness at day 0: 55.2 mg/L

Test temperature:

21.7 -23.5 °C

pH:

7.64 - 7.86

Dissolved oxygen:

Oxygen saturation: 100%

Nominal and measured concentrations:

Nominal test concentrations: control and 1 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria
- Type: open, loosely covered by glass tops
- Material, size, fill volume: glass, 2 L test volume per vessel
- Aeration: Gentle aeration
- Renewal rate of test solution: daily renewal (after 0, 24, 48, 72 hours)
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: less than 1 g fish per L test solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Tap water of local origin was used for holding and testing. The water was filtered on activated charcoal and aerated for at least 24 h to remove possible chlorine.
- Nominal water parameters: Total hardness: 10 - 250 mg CaCO3/L
pH-value: 6.0 - 8.5
- Culture medium different from test medium: no
- Intervals of water quality measurement: pH-value, temperature and oxygen saturation were measured
measurements in all vessels at the beginning of the test and every 24 h (from old and new media). Total hardness of the water was determined at the beginning out of the test control. During the test the water temperature was recorded continuously with a data logger (once per hour).

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: natural
- Light intensity: 0.1 - 10 µmol photons x m-2 x s-1

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Fish were considered dead if there was no visible movement (e.g. gill covers movement) and if touching of the caudal peduncle produced no reaction. Records were kept of visible abnormalities (e.g. loss of equilibrium, swimming behaviour, respiratory function, pigmentation, etc.). Observations were made after 24, 48, 72 and 96 h.

TEST CONCENTRATIONS
- Range finding study: No

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: No acute toxic effects within the range of solubility

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: No acute toxic effects within the range of solubility

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: No acute toxic effects within the range of solubility

Details on results:

- Behavioural abnormalities: Not observed
- Mortality of control: 0%
- Other adverse effects control: Not observed
- Abnormal responses: Not observed
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The test item solutions were clear.

Results with reference substance (positive control):

No reference substance tested

Sublethal observations / clinical signs:

Observations in the Test Vessels

                        (n=7)

Nominal loading [mg/L]	Effect*)	Test Duration [h]
		24	48	72	96
10	(1)	7/7	7/7	7/7	7/7
Control	(1)	7/7	7/7	7/7	7/7

*)  The number in brackets correspond to the following observation:    

                                    (1) =    Normal behaviour                              

                                  

Cumulative Mortality [%] in the Test Vessels

           

Nominal loading [mg/L]	Test Duration [h]
	24	48	72	96
10	0	0	0	0
Control	0	0	0	0

Validity criteria fulfilled:

yes

Conclusions:

No acute toxic effects occurred within the range of solubility. The test substance is with high probability acutely not harmful to fish.

Description of key information

Red disazo condensation pigments are with high probability acutely not harmful to fish.
No toxic effects occur at the range of the substances solubility.
EC50 (96h) > 1 mg/L (nominal) for Brachydanio rerio (OECD 203)

Additional information

The acute aquatic toxicity on fish was investigated in GLP guideline studies according to OECD 203 for two ‘red disazo condensation pigments’(CAS 68516-75-6 and CAS 71566-54-6) [DR.U.NOACK-LABORATORIEN, 2012; lnstitute of lndustrial Organic Chemistry, Branch Pszczyna, 2012]. Both studies used the zebrafish Danio rerio as test species. Based on the low water solubility of the test item, saturated stock solutions were prepared and the tests were conducted as limit tests with nominal concentrations of 1 mg/L (CAS 68516-75-6) and 100 mg/L (CAS 71566-54-6), respectively. After 96 hours of exposure no toxic effects on fish within the range of solubility were observed.