1,3'-Bipyridinium, 5'-[[4-[[4-[(1',2'-dihydro-6'-hydroxy-3,4'-dimethyl-2'-oxo[1,3'-bipyridinium]-5'-yl)azo]benzoyl]amino]phenyl]azo]-1',2'-dihydro-6'-hydroxy-3,4'-dimethyl-2'-oxo-, salt with 2-hydroxypropanoic acid (1:2)

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

Test set 1 from 27th to 31st August, 1990; test set 2 from 14th to 18th January, 1991; test set 3 from 15th to 19th April, 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

No chemical analysis of test concentrations was conducted.

Justification for type of information:

The test substance is the acid form of the substance under registration; justification for Read Across is detailed in the IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

updated 1983

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

no

Analytical monitoring:

no

Details on test solutions:

Test set 1: amounts of 1500, 150, 15 and 1.5 mg test article were presolved in test medium, sonicated for about 30 minutes and filled up to a final volume of 15 l test medium in the respective tanks.
Test set 2: a primary stock solution was prepared by making up 100 mg test article to 100 ml with test medium. 10 minutes sonication with ultrasound was applied to ensure total dispersion. 100 ml of this suspension were made up to 1000 ml with test medium to yield the secondary stock suspension. Quantities of 150 ml of the primary stock suspension and 150, 15 and 1.5 ml of the secondary stock suspension werem each made up to 15 l with test medium into the respective tank.
Test set 3: the two higher test concentrations were prepared by first dispersion 1500 and 150 mg test article in 1000 ml test medium, complete dispersion being accomplished by sonication and making up each dispersion to 15 l with test medium. For the low concentration, a dispersion of 100 mg test article in 1000 ml test medium was prepared similarly and a portion of 150 ml of it made up to 15 l test medium.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout.
- Source: P. Hohler, Forellenzucht Zeiningen, CH-4314 Zeiningen / Switzerland.
- Length at study initiation: 46 mm test set 1, 52 mm test set 2 and 47 mm test set 3.
- Weight at study initiation: 0.9 gram test set 1, 1.35 gram test set 2 and 1.07 gram test set 3.

ACCLIMATION
- Acclimation period: 5 weeks test set 1, 11 weeks test set 2 and 6 weeks test set 3.
- Acclimation conditions: 250 litres tank; continuous-flow filtered and aerated tap water, 5-micron Filter.
- Teperature: 13.0 - 17.0 °C
- Type and amount of food during acclimation: "Forellenfutter" (KLIBA, Klingentalmuhle AG, CH-4303 Kaiseraugst/Switzerland), commercially available.
- Feeding frequency during acclimation: three times a week.

ADAPTATION
- Adaptation period: 7 days.
- Adaptation conditions: 250 litres tank; reconstituted water, as during the test.
- Temperature: 16.0 - 18.0 °C test set 1, 11.5 - 14.5 °C test set 2 and 14.0 - 15.0 °C test set 3.
- Aeration: continuous.
- Feeding: once daily, until 1 day prior to treatment.
- Health/mortality: no mortality.

FEEDING DURING TEST
Food was withheld from the trout one day before and throughout the exposure period of 96 hours.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

15.5 - 16.0 °C test set 1
14.5 °C test set 2
15.0 °C test set 3

pH:

7.9 - 8.1 test set 1
8.0 - 8.3 test set 2
8.1 - 8.2 test set 3

Dissolved oxygen:

ranging from 10.1 to 11.8 mg O2 per litre test set 1
ranging from 10.5 to 11.9 mg O2 per litre test set 2
ranging from 8.9 to 12.2 mg O2 per litre test set 3

Nominal and measured concentrations:

100, 10, 1.0 and 0.1 mg/l (nominal) test set 1
1.0, 0.1, 0.01 and 0.001 mg/l (nominal) test set 2
1.0, 10 and 100 mg/l (nominal) test set 3

Details on test conditions:

TEST SYSTEM
- Test vessel: 15 litre, all-glass.
- Aeration: the water was continuously aerated using high-pressure air.
- No. of organisms per vessel: 10 trout per each treatment and the control group, respectively; 140 total.
- Biomass loading rate: mean of 0.6 - 1.0 g fish/litre of test medium.

TEST MEDIUM / WATER PARAMETERS
- Preparation of dilution water: the test medium was prepared from deionized water by adding the foilowing amounts of salt: 294.00 mg/l CaCl2 × 2H2O; 123.2 mg/l MgS04 × 7H2O;64.80 mg/1 NaHCO3; 5.75 mg/l KCl.
- Total hardness: 14 dH°.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours of artificial fluorescent light, per day.
- Light intensity: approximately 500 - 1500 Lux.

EFFECT PARAMETERS MEASURED
- Mortality: daily recorded.
- Ciihicai signs (symptoms): recorded 2, 24, 48, 72 and 96 hours after starting the treatment.
- Fish size: measured with a ruler.
- Body weight: prior to treatment all fish of each tank were weighed and the total weight of the fish of each tank were added together and divided by the total number of fish used for the test.
- pH: prior to addition of test article and 2, 24, 48, 72 and 96 hours after the treatment, using the WTW OXI-Meter
- Teperature: prior to addition of test article and 2, 24, 48, 72 and 96 hours after the treatment, using a thermometer.

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

NOEC (96h): 1.0 mg/l (nominal)
LOEC (96h): 10 mg/l (nominal)

In Test set 1, it was not clear whether the mortality rates were an effect of the test article and therefore additions tests were performed.
In Test set 2 and 3, no fish died at any concentration during the test. The mortality of the controls was also 0 %.

CLINICAL SIGNS
Clinical signs observed in Test set 1 were not taken into consideration for the NOEC and LOEC determination.
In Test set 2 and 3, no clinical signs were recorded in the control tanks and in the treated tanks up to test concentration of 1.0 mg/l. Clinical signs observed at the test concentration of 10 mg/l are summarized in table below. At the test concentration of 100 mg/l the test medium was too turbid to allow the observation of clinical signs.

TEST SOLUTION APPEARANCE
At the test concentration of 1.0 mg/l, 10 mg/l and 100 mg/l a deposit on the tank bottom was observed in the first test set.
At the test concentration of 0.1 mg/l a deposit on the tank bottom was observed after 72 hours and at the test concentration of 1.0 mg/l after 48 hours in the second test set.
In the third test, deposits on the tank bottom were observed for all concentrations after 2 hours.

Sublethal observations / clinical signs:

Mortality

Conc. of test item (mg/l)	N. of fish	Exposure time (hrs)						Cumulative N. deaths	Cumulative deaths (%)
		0	2	24	48	72	96
Test set 1
0	10	0	0	0	0	1	1	1	10
0.1	10	0	0	0	1	3	4	4	40
1.0	10	0	0	0	1	2	2	2	20
10	10	0	0	0	0	1	1	1	10
100	10	0	0	0	0	0	0	0	0
Test set 2
0	10	0	0	0	0	0	0	0	0
0.001	10	0	0	0	0	0	0	0	0
0.01	10	0	0	0	0	0	0	0	0
0.1	10	0	0	0	0	0	0	0	0
1.0	10	0	0	0	0	0	0	0	0
Test set 3
0	10	0	0	0	0	0	0	0	0
1.0	10	0	0	0	0	0	0	0	0
10	10	0	0	0	0	0	0	0	0
100	10	0	0	0	0	0	0	0	0

Observed clinical signs in fish at different concentrations of the test article

Test set 1

Concentration of test item (mg/l)	Clinical signs	N. of fish	Time* (hrs)
0.1	head dominant swimming	1
0.1	loss of equilibrium	1	96
0.1	enhanced respiratory rate	3	48-96
0.1	enhanced respiratory rate	5	24
0.1	enhanced respiratory rate	6	48
0.1	remaining at the bottom of the tank	3	72-96
0.1	remaining at the bottom of the tank	4	24
0.1	remaining at the bottom of the tank	3	48
1	loss of equilibrium	1	72-96
1	enhanced respiratory rate	4	24
1	enhanced respiratory rate	6	24
1	enhanced respiratory rate	5	48
1	enhanced respiratory rate	4	72
1	irreguiar respiratory rate	1	96
1	remaining at the bottom of the tank	1	72-96
1	remaining at the bottom of the tank	2	48-72
10	loss of equilibrium	1	96
10	loss of equilibrium	2	2
10	loss of equilibrium	3	24
10	loss of equilibrium	2	48
10	loss of equilibrium	1	72
10	enhanced respiratory rate	1	96
10	enhanced respiratory rate	9	2
10	enhanced respiratory rate	10	24
10	enhanced respiratory rate	9	48
10	enhanced respiratory rate	8	72
10	remaining at the bottom of the tank	8	96
10	remaining at the bottom of the tank	9	24
10	remaining at the bottom of the tank	7	48
100	**		72-96

* If no time interval is given, the corresponding clinicai signs were only observed at the indicated time.

** Ciinicai signs could not be detected, since the test medium was too turbid.

Test set 2 and 3

Conc. of test item (mg/l)	Clinical signs	N. of fish	Time (hrs)
10	Irregular respiratory rate	10	2 - 96
10	Reduced respiratory rate	10	48 - 96
100	*

* At 100 mg/l observation of the fish was not possible owing to the high turbidity of the test medium.

Temperature values

Concentration of test item (mg/l)	Exposure time (hrs)
	0	2	24	48	72	96
Test set 1
0	16.0	16.0	15.5	15.5	15.5	16.0
0.1	16.0	16.0	15.5	16.0	15.5	16.0
1.0	16.0	16.0	15.5	16.0	15.5	16.0
10	16.0	16.0	16.0	16.0	15.5	16.0
100	16.0	16.0	16.0	16.0	15.5	16.0
Test set 2
0	14.5	14.5	14.5	14.5	14.5	14.5
0.001	14.5	14.5	14.5	14.5	14.5	14.5
0.01	14.5	14.5	14.5	14.5	14.5	14.5
0.1	14.5	14.5	14.5	14.5	14.5	14.5
1.0	14.5	14.5	14.5	14.5	14.5	14.5
Test set 3
0	15.0	15.0	15.0	15.0	15.0	15.0
1.0	15.0	15.0	15.0	15.0	15.0	15.0
10	15.0	15.0	15.0	15.0	15.0	15.0
100	15.0	15.0	15.0	15.0	15.0	15.0

pH values

Concentration of test item (mg/l)	Exposure time (hrs)
	0	2	24	48	72	96
Test set 1
0	8.1	8.1	7.9	7.9	7.9	7.9
0.1	8.1	7.9	7.9	7.9	7.9	8.0
1.0	8.1	7.9	7.9	7.9	7.9	8.0
10	8.1	8.0	7.9	7.9	8.0	8.0
100	8.1	8.0	7.9	8.0	8.0	8.0
Test set 2
0	8.3	8.2	8.1	8.1	8.2	8.2
0.001	8.3	8.2	8.1	8.1	8.2	8.2
0.01	8.3	8.2	8.1	8.1	8.2	8.2
0.1	8.2	8.2	8.1	8.1	8.2	8.2
1.0	8.2	8.1	8.1	8.0	8.1	8.1
Test set 3
0	8.2	8.1	8.1	8.1	8.1	8.2
1.0	8.2	8.1	8.1	8.1	8.1	8.2
10	8.2	8.1	8.1	8.1	8.1	8.1
100	8.2	8.1	8.1	8.1	8.1	8.1

Dossolved oxygen content (mg O₂/l)

Concentration of test item (mg/l)	Exposure time (hrs)
	0	2	24	48	72	96
Test set 1
0	11.6	11	10.4	10.1	10.3	10.4
0.1	11.7	11.1	10.5	10.2	10.4	10.3
1.0	11.6	11.1	10.6	10.1	10.2	10.1
10	11.8	10.9	10.6	10.2	10.3	10.4
100	11.7	11.0	10.6	10.2	10.4	10.2
Test set 2
0	11.1	10.8	10.7	11.7	11.8	10.9
0.001	11.1	10.8	10.7	11.8	11.9	10.9
0.01	11.1	10.8	10.7	11.8	11.8	10.9
0.1	11.0	10.6	10.5	11.5	11.5	10.7
1.0	10.9	10.6	10.5	11.5	11.5	10.7
Test set 3
0	12.2	8.9	9.0	11.7	11.6	11.5
1.0	11.9	9.1	9.2	11.6	11.4	11.3
10	11.7	9.1	9.4	11.6	11.3	11.3
100	11.7	9.1	9.4	11.5	11.0	11.9

Conclusions:

LC50 (96h) > 100 mg/l (nominal)

Executive summary:

The toxicity of test item on rainbow trout was assessed over 96 hours in a static-system, according to the OECD guideline 203. Concentrations in the range of 0.001 to 100 mg/l were tested.

In Test set 1, it was not clear whether the mortality rates were an effect of the test article and therefore additions tests were performed. In Test set 2 and 3, no fish died at any concentration during the test. The mortality of the controls was also 0 %.

Clinical signs observed in Test set 1 were not taken into consideration for the NOEC and LOEC determination.

At the test concentration of 1.0 mg/l, 10 mg/l and 100 mg/l a deposit on the tank bottom was observed in the first test set. At the test concentration of 0.1 mg/l a deposit on the tank bottom was observed after 72 hours and at the test concentration of 1.0 mg/l after 48 hours in the second test set. In the third test, deposits on the tank bottom were observed for all concentrations after 2 hours.

The NOEC and LOEC values were found to be lower than 1.0 mg/l and 10 mg/l, respectively. The LC50 was found to be greater than 100 mg/l.

Conclusion

LC50 (96h) > 100 mg/l (nominal)

Description of key information

Not harmful-toxic to fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

There are two old internal reports reguarding the Basic Orange 064 potential for short-term toxicity to fish. The test were performed according to internal method (modified routine bioassay method, 1.11.1974). Althought, different LD50 (48h) values were reported, i.e. 280 mg/l and higher then 500 mg/l, the effects recorded can be considered as not in desagree: it should be noted that lots tested were characterized by a different test item content and that the most severe effects were recorded with the lot having the higher test item amout.

Unfortunately, only a sheet of the test results is available in both the cases, thus a reliability cannot be confirmed due to the absence of the testing procedures and results details.

In order to confirm and to assess the substance behaviour, the available data on the structural analogue Similar Substance 01 has been taken into consideration. Similar Substance 01 is the acid form of Basic Orange 064; the read across approach can be considered as adequate and suitable to assess the short-term toxicity potential of the substance under registration (details on read across approach are given in attachment in the IUCLID section 13).

The toxicity of Similar Substance 01 was assessed in rainbow trout, over 96 hours, in a static-system. Testing method and procedures followed were in accordance to the OECD guideline 203. Concentrations in the range of 0.001 to 100 mg/l were tested. In the two experiments following a failed first one, no fish died at any concentration during the test, as well as in the controls. At the test concentrations of 1.0 mg/l, 10 mg/l and 100 mg/l a deposit on the tank bottom was observed in the first test set. At the test concentration of 0.1 mg/l a deposit on the tank bottom was observed after 72 hours and at the test concentration of 1.0 mg/l after 48 hours in the second test set. In the third test, deposits on the tank bottom were observed for all concentrations after 2 hours. The NOEC and LOEC values were found to be lower than 1.0 mg/l and 10 mg/l, respectively. The LC50 was found to be greater than 100 mg/l.