Chromate(5-), bis[4-(hydroxy-κO)-7-[2-(2-hydroxy-1-naphthalenyl)diazenyl]-3-[2-[2-(hydroxy-κO)- 3-nitro-5-sulfophenyl]diazenyl]-2-naphthalenesulfonato(4-)]-, sodium (1:5)

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:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Stability of the test substance under test conditions was determined by analyzing samples taken from a solution containing 10 mg/l during the range-finding test.
Sampling:
-Frequency: at t=0 h, t=24 h and t=96 h.
-Volume: 10 ml from the approximate centre of the test vessel.
-Storage: samples were transferred to Analytical Chemistry on the day of sampling.

During the final test duplicate samples were taken from 0, 10, 32 and 100 mg/l for analyses.
Sampling:
-Frequency: at t=Oh and t=96h (actually: 99 h).
-Volume: 10 mi from the approximate centre of the test vessels.
-Storage: samples were transferred to Analytical Chemistry on the day of sampling.

Additlonally, reserve samples of 25 ml were taken from all concentrations. These samples were frozen for possible analysls and stored until delivery of the final report wlth a maximum of three months.

SAMPLE PRETREATMENT
All samples not analysed on the same day of sampling were frozen until analysis.
The frozen samples were defrosted at room temperature. The samples of 0 mg/l were not pre-treated. The entire volume of each sample of 10, 32 and 100 mg/l was transferred quantitatively into a suitable volumetric flask. The flask was filled up to the mark with Milli-Q water. If necessary, the solutions were further diluted using Milli-Q water to obtain concentrations in the calibration range.

Vehicle:

no

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
-Common name: Carp
-Source: Zodiac, proefacc, "De Haar Vissen", L.U. Wageningen, the Netherlands.
-Length at study initiation: 3.7 ± 0.2 cm
-Weight at study initiation: 0.81 ± 0.11 g
-Characteristics: pathogen-free F1 from a single parent-pair

ACCLIMATION
-Acclimation period: 12 days
-Type and amount of food during acclimation: daily with Trouvit or Artemia.
-Feeding frequency during acclimation: daily
-Other: oxygen concentration, pH, nitrate and nitrite concentration and ammonia concentration were measured once a week and temperature every day.

FEEDING DURING TEST
-Frequency: no feeding from 24 hours prior to the test and during the total test period.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

250 mg CaCO3 per litre

Test temperature:

20 - 22.5 °C

pH:

8.2

Dissolved oxygen:

8.6 - 9.8 mg O2/l

Nominal and measured concentrations:

Nominal: 10, 18, 32, 56 and 100 mg/l
Analysis of the samples taken at the start (t=0) of the final test revealed mean actual concentrations of 9.3 mg/l (93%), 29.2 mg/l (91%) and 95.8 mg/l (96%) at the nominal concentrations of 10, 32 and 100 mg/l, respectively.

Details on test conditions:

TEST SYSTEM
-Test vessel: 8 litres, all-glass.
-Aeration: The test media were aerated continuously during the test.
-No. of organisms per vessel: 7
-Loading: 0.8 g fish/litre, i.e.7 fish per 7 litres of test medium.
-Control: test medium without test substance or other additives.
-Introduction of fish in test medium: directly after the preparation of test media

TEST MEDIUM
The test media were prepared using a stock solution in ISO-medium. For this purpose the test substance was added quantitatively providing a concentration of 1000 mg/l. The final test solutions were all black (bluish according to observations in the range-finding test). Due to this heavy coloring it was not possible to determine whether the test substance was dissolved completely or not.
-Source/preparation of dilution water:
ISO-medium, formulated using Milli-Ro water (tap-water purified by reverse osmosis) with the following composition:
Ca2+ 80 mg/l
Mg2+ 12 mg/l
Na+ 15 mg/l
K+ 3 mg/l
Cl- 145 mg/l
SO4-- 49 mg/l
HCO3- 47 mg/l
This dilution water was aerated until the dissolved oxygen concentration had reached saturation and the pH had stabilized.

OTHER TEST CONDITIONS
-Photoperiod: 16 hours photoperiod daily

TEST CONCENTRATIONS
-Range finding study: yes
A range-finding test was performed to provide information about the range of concentrations to be used in the final test. 3 fish per concentration were exposed to a concentration range of 0,1 to 100 mg/l with an increasing factor of 10.

STABILITY TEST
The analytic results showed the substance to be stable under test conditions for at least 96 hours.

DATA HANDLING
The LC50 was determined using the maximum likelihood estlmatlon method with the probits of the percentages of dead fish as function of the logarithms of the corresponding concentrations. All calculations were based on nominal concentrations if the actual concentrations were > 80% of the
nominal concentrations.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

49 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CI (44 and 64 mg/l)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

During the exposure period the actual concentration remained > 90 % of nominal at all three concentrations sampled.
-Range-finding test: 100% mortality of fish was recorded at 100 mg/l. No mortality was seen at or below 10 mg/l.
-Final study: the test substance induced no lethal effects in carp at or below 32 mg/l. The calculated LC50 value was reached after 48 hours of exposure and remained constant during the remaining test period.
-Acceptability of the test: in the control no mortality was observed. The mean length of the fish was just below the lower limit of the range prescribed by the protocol. However, since it was within the range recommended by the OECD guideline, the fish could be used for testing. Further, all test conditions remained within the ranges prescribed by the protocol. A deviation of 0.5 °C for room temperature outside the range of ± 1° C, does not have a significant influence on the integrity of the study.

Validity criteria fulfilled:

yes

Conclusions:

LC50 (96)= 49 mg/l

Executive summary:

The acute toxicity of test item to fish was investigated on Cyprinus carpio according to the method C.1 of EEC-Directive 92/69 EEC. Seven fish were exposed for 96 h in a static system to a nominal concentration range from 10 to 100 mg/l.

The analytic results showed that the substance was stable under test conditions for at least 96 hours. The LC50 (96h) was calculated to be 49 mg/l (95 % confidence interval between 44 and 64 mg/l) and NOEC was found to be 32 mg/l.

Description of key information

LC50= 49 mg/l

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

49 mg/L

Additional information

The acute toxicity of test item to fish was investigated on Cyprinus carpio according to the method C.1 of EEC-Directive 92/69 EEC. Seven fish were exposed for 96 h in a static system to a nominal concentration range from 10 to 100 mg/l.

The analytic results showed that the substance was stable under test conditions for at least 96 hours. The LC50 (96h) was calculated to be 49 mg/l (95 % confidence interval between 44 and 64 mg/l) and NOEC was found to be 32 mg/l.