Disodium [N-(2-chlorophenyl)-2-[(2-hydroxy-5-nitrophenyl)azo]-3-oxobutyramidato(2-)][3-hydroxy-4-[(2-hydroxy-1-naphthyl)azo]-7-nitronaphthalene-1-sulphonato(3-)]chromate(2-)

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:

June 10, 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

not specified

Principles of method if other than guideline:

The acute fish toxicity testing was performed according to published methods, which were adapted and standardized for the specific needs of the company. This method was comparable to today’s standard testing procedure published by the OECD within Guideline for Testing of Chemicals 203: Fish, Acute Toxicity Test, adopted by the Council on 17th July 1992.

GLP compliance:

no

Vehicle:

not specified

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebrafish
- Source: West Aquarium GmbH, D-3422 Bad Lauterberg
- Age at study initiation: 4-6 months
- Length at study initiation: 3 cm
- Weight at study initiation: 0.25-0.35 g
- Feeding during test: daily
- Food type: TETRA MIN, flocks

ACCLIMATION
- Acclimation period: minimum 12 days
- Acclimation conditions (same as test or not): 21-25 °C
- Type and amount of food: TETRA MIN, flocks
- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

No post exposure observation period

Test temperature:

21-25°C

pH:

from 8.0 to 8.2

Dissolved oxygen:

from 6.6 to 7.0 mg/l

Nominal and measured concentrations:

Nominal concentrations:
1.0/3.0/10.0/30.0/100.0 mg/l

Details on test conditions:

TEST SYSTEM
- Material: full-glass basins
- No. of organisms per concentration: 10

TEST MEDIUM / WATER PARAMETERS
- Artificial testing water: 1.5 ml Stock-solution 1, 1.5 ml Stock-solution 2, 15 ml Stock-solution 3 and 1 liter of deionized water
- Stock solutions composition:
Stock-solution 1:
250 g CaCl2 x 2 H2O (Merck 2382)
29 g NaCl (Merck 6404E)
9 g NaNO3 (Merck 6537)
add 1 liter of deionized water

Stock-solution 2:
115 g MgSO4 x 7 H2O (Merck 5886)
79 g Na2SO4 (Merck 822286)
add 1 liter of deionized water

Stock-solution 3:
27 g NaHCO3 (Merck 6329E)
add 1 liter of deionized water

OTHER TEST CONDITIONS
- Adjustment of pH: pH kept between 6 and 8.5. In case of deviations, pH adjusted with NaOH or HCl solution.
- Photoperiod: 12 hours light cycle

TEST CONCENTRATIONS
- Test concentrations: 1.0/3.0/10.0/30.0/100.0 mg/l

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

ca. 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

ca. 2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Conclusions:

LC50 = 2 mg/l

Executive summary:

Method

The test has been performed fundamentally according to OECD Guideline 203 principle.

10 replicates of zebrafish between 4 -6 months age were exposed to the test substance for a period of 96 hours. The water in each basin was prepared according to ISO guidelines. Testing water was kept at a pH between 6 and 8.5 and O2 concentration ranged between 7.5 to 8.6 mg/L. The nominal concentrations of substance used for the test were: 1.0/3.0/10.0/30.0/100.0 mg/l.

Mortalities were recorded at 4, 24, 48, 72 and 96 hours to determine the concentrations which kill 50 % of the fish (LC50) where possible.

Results

The LC50 observed at 96h was 2 mg/l.

Description of key information

LC50 to fish = 2 mg/l.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

2 mg/L

Additional information

The assessment of short-term toxicity to fish of the substance under registration is based on two studies.

The key study (Huntsman, 1981) was conducted on zebrafish following a procedure similar to OECD 203. The purity of the substance was 56.78%. The tested concentrations were: 1.0/3.0/10.0/30.0/100.0 mg/l. The LC50 after 96 hours of exposure was 2 mg/l.

The supporting study (Huntsman, 1984) was performed with a lower purity of test article, 28%. The procedure was similar to OECD 203 guideline and the test system was zebrafish. The following concentrations of substance were tested: 1.0/3.0/10.0/30.0 mg/l. The LC50 calculated was 4 mg/l.

The two studies were performed according to similar procedures and using the same test substance; the results were similar but in the key study was used a test article with higher purity than the one used in the supporting study. The LC50 obtained in the key study, 2 mg/l, is little lower and more precautionary than the LC50 obtained in the supporting study, 4 mg/l.