Sodium 4-[4-[[2-methyl-4-[[(p-tolyl)sulphonyl]oxy]phenyl]azo]anilino]-3-nitrobenzenesulphonate

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:

From April 06th to May 19th, 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Part I, May 12, 1981, adopted 1984

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test substance was dissolved in the test medium at a concentration of 100 mg/l (stock solution). Thereafter, series of sequential dilutions with the test medium were prepared to obtain the final test concentrations of the test article.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Breeding: bred in the testing laboratories, under standardized conditions.
- Age at study initiation: age of less than 24 hours.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test temperature:

21.5 °C

pH:

Start: 8.3 - 8.4
End: 8.3 - 8.4

Dissolved oxygen:

Start: 8.4 - 8.8 mg/l
End: 8.6 - 9.1 mg/l

Nominal and measured concentrations:

1, 10 and 100 mg/l nominal

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml beakers, containing 20 ml of test medium.
- Aeration: test medium was aerated to an oxygen concentration of 8 mg/l.
- No. of organisms per vessel: 10 animal.
- No. of vessels per concentration: 2 replicates.
- No. of vessels per control: 2 replicates.

TEST MEDIUM / WATER PARAMETERS
- Preparation of dilution water: according to the OECD guideline. The water used was bidlstilled water.
- Total hardness: 14 dH°.
- CaCl2 x 2H2O: 294 mg/l
- MgSO4 x 7H2O: 123 mg/l
- NaHCO3: 65 rng/l
- KCl: 5.8 mg/l

OTHER TEST CONDITIONS
- Adjustment of pH: the pH of the reconstituted water was abjusted to 8.2.
- Photoperiod: 16 hours of illumination.
- Light intensity: 1000 Lux.

EFFECT PARAMETERS MEASURED
Test evaluations were done according to the OECD guideline 202 by visual control of the mobility of the daphnids after 24 hours. Basect on the data, an estimate of the EC0, 50 and 100 was given.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The EC0 was identified in the range of 1 - 10 mg/l

Immobilization of Daphnia magna

Conc. Of test article (mg/l)	N. of animals	N. of responses 24 hrs	% of responses 24 hrs
0	10	1	10
0	10	0	0
1	10	0	0
1	10	0	0
10	10	0	0
10	10	1	10
100	10	1	10
100	10	1	10

Validity criteria fulfilled:

yes

Remarks:

in the control, not more than 10 % of the Daphnia have been immobilized or trapped at the surface of the water and dissolved oxygen concentration was ≥ 60 % of the air saturation

Conclusions:

EC50 (24h) > 100 mg/l (nominal)

Executive summary:

The acute toxicity of the test substance to Daphnia magna was investigated over a period of 24 hours, following the OECD guideline 202. The nominal test concentrations applied were 1, 10 and 100 mg/l. No chemical analysis of the test substance concentration was conducted. No deaths occurred at the nominal concentration of 1 mg/l; at the nominal concentrations of 10 and 100 mg/l 10 % of total fish died after 24 hours of exposure. 10 % of mortality was also observed in one of the two the blank controls.

The EC0 was identified to be in the range of 1 - 10 mg/l.

Conclusion

EC50 (24h) > 100 mg/l (nominal)

Description of key information

Not short-term harmful/toxic to aquatic invertebrates.

Additional information

The acute toxicity of the test substance to Daphnia magna was investigated over a period of 24 hours, following the OECD guideline 202. The nominal test concentrations applied were 1, 10 and 100 mg/l. No chemical analysis of the test substance concentration was conducted. No deaths occurred at the nominal concentration of 1 mg/l; at the nominal concentrations of 10 and 100 mg/l 10 % of total fish died after 24 hours of exposure. 10 % of mortality was also observed in one of the two the blank controls. The EC0 was identified to be in the range of 1 - 10 mg/l, while the EC50 (24h) value was indicated to be higher than 100 mg/l (nominal).

A second experiment is available. It was performed on Daphnia magna, over a period of 48 hours and following the OECD guideline 202. The following nominal test concentrations were chosen and tested in duplicate: 0.9, 1.9, 4.3, 9.4, 21 and 45 mg/l. No chemical analysis of the test substance concentrations was performed. In this case test, weak sedimentation was observed after 48 hours at the concentration of 21 mg/l; at 45 mg/l moderate sedimentation was observed at 24 and 48 hours. The EC50 (48h) was indicated to be 31 mg/l (nominal, geom mean).

The second experiment performed on daphnia has been judged as not reliable due to sedimentation recorded; in fact, effects were recorded at concentrations at which weak/moderate sedimentation occurred. Thus, the test results could be negatively impacted due to physical effects. Sedimentation is consistent with the substance behaviour observed in the Lemna experiment: the medium used is similar to that used in the daphnia experiment. The preparation of stock solution for the Lemna test resulted in a dense, dark orange suspension that was then filtrated to separate the possible non-dissolved test material. During filtration strong coloration of the membrane was observed due to undissolved test item residue, resulting in a light orange test item stock solution. The test solutions of the subsequent lower test concentrations were prepared. The highest concentration reachable was 0.69 mg/l.