Disodium [3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-4-hydroxybenzenesulphonato(3-)][1-[[2-hydroxy-5-(phenylazo)phenyl]azo]-2-naphtholato(2-)]chromate(2-)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Code number: FAT 21095/C
EN/Batch: 34
Purity: ca. 80 %
Appearance: black solid
Expiry date: 07/99

Analytical monitoring:

yes

Details on sampling:

Composite samples of each test concentration were drawn by mixing identical volumes of the test solutions taken from the approximate center of the test vessels. They were taken immediately before exposure and after 48 hours exposure and kept at -18 °C to -22 °C until analysis.

Vehicle:

no

Details on test solutions:

Stock solution: 100.6 mg test substance were mixed and made up to 1000 ml with water

Test organisms (species):

Daphnia magna

Details on test organisms:

Test system: Daphnia magna
Strain: Straus 1820
Source: CIBA-GEIGY Ltd, testing facility
Number of daphnids: 20 per concentration and control. 4 replicates of 5 daphnia each.
Feeding: None during the test.
Breeding: Cultures of daphnia are maintained in glass vessels containing approx. 2.5L of reconstituted water at 20 ± 1 °C (water is renewed partially thrice weekly). At each renewal the daphnia are fed with a suspension of green algae (Scenedesmus subspicatus) supplemented by a suspension of TETRAMIN extract in such quantities that the food is consumed after 24h.

Pretreatment: 24 hours before the begin of the exposure reproductive daphnia are separated from the young by sieving all individuals through a 800 µm sieve. This operation is repeated immediately before the exposure and the young (0- 24h of age) are retained for the test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

240 mg CaCO3/l

Test temperature:

20 ± 1 °C

pH:

7.9 - 8.0

Nominal and measured concentrations:

Nominal concentrations: 0.91, 2.0, 4.4, 9.6, 21 and 46 mg/l
Measured concentrations: 0.9, 2.0, 4.5, 10.1, 23.4, 53.3 mg/l

Details on test conditions:

- Vessels: Beakers covered with watch glasses 100 ml solution per beaker.
- Water: Reconstituted water containing
- 65 mg NaHC03
- 294 mg CaCl2 • 2 H20
- 123 mg MgS04 • 7 H20
- 6 mg KCl
in 1000 ml bidistilled water.
The water was aerated with clean air for at least 24 hours before use.

- Aeration: None
- Lighting: Fluorescent light, 16 hours daily approx. 1500 lux
- Number of Daphnia: 20 per concentration and control. 4 replicates of 5 daphnids each.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

15.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 12.5 - 19.8 mg/L and Goodness of fit CHI is 4.59

Details on results:

Values observed
- NOEC (48 h): 2 mg/l
- EC 0 (48 h): 2 mg/l
- EC 100 (48 h): 46 mg/l

Controls
Immobilizations in blank: 0

Remarks:
The measured test substance concentrations were within the range of 100 ± 20 % of the nominal test concentrations, therefore values are based on nominal concentrations.

Reported statistics and error estimates:

The LC-50 values were calculated according to the maximun likelihood method, probit model (Mc Cullagh, P., Neider, J.A., 1983: Generalized
linear models, Chapman & Hall, Lon. EC-values were graphically determined on gausso-logarithmic probability paper.

Immobilization

(Initial numbers of daphnia = 20/test cone.)

Conc. Nominal	Number of Daphnia immobalized after 24 hrs exposure
mg/l	Vessel				Total	%
	1	2	3	4
Blank	0	0	0	0	0	0
0.91	0	0	0	0	0	0
2	0	0	0	0	0	0
4.4	0	0	0	1	1	5
9.6	0	0	0	0	0	0
21	3	1	0	0	4	20
46	1	2	3	3	9	45

Conc. Nominal	Number of Daphnia immobalized after 48 hrs exposure
mg/l	Vessel				Total	%
	1	2	3	4
Blank	0	0	0	0	0	0
0.91	0	0	0	0	0	0
2	0	0	0	0	0	0
4.4	0	0	0	1	1	5
9.6	1	0	0	1	2	10
21	3	5	2	4	14	70
46	5	5	5	5	20	100

Validity criteria fulfilled:

yes

Conclusions:

The 48h EC50 of FAT 21095/C was determined to 15.6 mg/L.

Executive summary:

The acute toxicity test on Daphnia magna (Straus 1820) was performed on test item FAT 21095/C according to the 92/69/EEC C.2 Acute toxicity for Daphnia method. 20 daphnids (0-24 hours old) were exposed to nominal concentrations of 0.91,2.0,4.4, 9.6, 21 and 46 mg test substance/L respectively. A static system was used for this test. Animals were observed for immobilization after 24 and 48 h. The measured test substance concentrations were within the range of 100 ± 20% of the nominal test concentrations, therefore values are based on nominal concentrations. Following results were obtained:

EC 50 ( 48 h) calculated: 15.6 mg/l

95 % confidence limit: 12.5 -19.8 mg/l

Goodness of fit CHI: 4.59

EC 50 ( 24 h) calculated: 57 mg/l

95 % confidence limit: 35.1-194 mg/l

Goodness of fit CHI: 3.34

NOEC ( 48 h ): 2.0 mg/l

EC 0 ( 48 h ): 2.0 mg/l

EC 100 (48h): 46 mg/l

Description of key information

The acute toxicity test on Daphnia magna (Straus 1820) was performed on test item FAT 21095/C according to the 92/69/EEC C.2 Acute toxicity for Daphnia method. 20 daphnids (0-24 hours old) were exposed to nominal concentrations of 0.91,2.0,4.4, 9.6, 21 and 46 mg test substance/L respectively. A static system was used for this test. Animals were observed for immobilization after 24 and 48 h. The measured test substance concentrations were within the range of 100 ± 20 % of the nominal test concentrations, therefore values are based on nominal concentrations. Following results were obtained:

EC 50 ( 48 h) calculated: 15.6 mg/l

95 % confidence limit: 12.5 -19.8 mg/l

Goodness of fit CHI: 4.59

EC 50 ( 24 h) calculated: 57 mg/l

95 % confidence limit: 35.1-194 mg/l

Goodness of fit CHI: 3.34

NOEC ( 48 h ): 2.0 mg/l

EC 0 ( 48 h ): 2.0 mg/l

EC 100 (48h): 46 mg/l

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

15.6 mg/L