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 aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Study period:

May from 22nd to 29th, 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

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 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

May 12, 1981, adopted 1983

GLP compliance:

no

Analytical monitoring:

no

Details on test solutions:

Test item was dissolved in the test medium at a concentration of 100 mg/100 mI (stock solution).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Age of parental stock: less than 24 hours.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test temperature:

20 ± 2 °C

pH:

Start: 7.7
End: 7.9

Dissolved oxygen:

Start: 8.8 mg/l
End: 8.5 mg/l

Nominal and measured concentrations:

Nominal 31.25, 62.5, 125, 250, 500 and 1000 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mI beakers, containing 20 ml test medium.
- No. of organisms per vessel: 10
- No. of vessels per concentration: 2 replicates
- No. of vessels per control: 2 replicates

TEST MEDIUM / WATER PARAMETERS
- Terst medium: the test medium used was prepared according to the EEC Directive; the compositin was: CaCl2 × 2H2O 294 mg/l, MgSO4 × 7H2O 123 mg/l, NaHCO3 65 mg/l, KCl 5.8 mg/. The water used was bi-distilled water.
- pH: 7.9 ± 0.3

EFFECT PARAMETERS MEASURED
Test evaluations were done according to the OECD guideline by visual control of the mobility of the daphnids after 24 hours. The EC50 estimate was determined by using the Logit modet. EC0 and EC100 values were determined experimentally.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

299 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

EC50 (24h): 299 mg/. The 95 %-confidence Iimits for the EC50 (24h) were 136.7 - 783.3 mg/l
The dose response line was found to be Logit (24h) = -3.562 + 0.6249 log (dose).
The 95 %-confidence Iimits for the slope were (24h): 0.5326 - 0.7172.

The EC0 after 24 hours was determined to be 31.25 mg/l; the EC100 value was found to be higher than 1000 mg/l for 24 hours of exposure.

Results with reference substance (positive control):

EC50 (24h): 1.484 mg/l
The 95 %-confidence Iimits for the EC50 (24h) value were 1.315 -1.713 mg/l.
The dose response line was found to be Logit (24h) = -1.562 + 3.96 log (dose).
The 95 %-confidence Iimits for the slope were (24h): 3.085 - 4.834.

Influence of test item in the immobilization of Daphnia magna

Vessel	No of animals	No of deaths (24 hrs)	% immobilization (24 hrs)
Control	10	0	0
Control	10	0	0
Test item 31.25 mg/l	10	0	0
Test item 31.25 mg/l	10	0	0
Test item 62.5 mg/l	10	2	20
Test item 62.5 mg/l	10	1	10
Test item 125 mg/l	10	4	40
Test item 125 mg/l	10	5	50
Test item 250 mg/l	10	5	50
Test item 250 mg/l	10	6	60
Test item 500 mg/l	10	5	50
Test item 500 mg/l	10	5	50
Test item 1000 mg/l	10	7	70
Test item 1000 mg/l	10	7	70

Influence of reference substance potassium dichromate in the immobilization of Daphnia magna

Vessel	No of animals	No of deaths (24 hrs)	% immobilization (24 hrs)
Control	10	0	0
Control	10	0	0
Potassium dichromate 0.04 mg/l	10	0	0
Potassium dichromate 0.04 mg/l	10	0	0
Potassium dichromate 0.08 mg/l	10	0	0
Potassium dichromate 0.08 mg/l	10	0	0
Potassium dichromate 0.2 mg/l	10	0	0
Potassium dichromate 0.2 mg/l	10	0	0
Potassium dichromate 0.6 mg/l	10	0	0
Potassium dichromate 0.6 mg/l	10	0	0
Potassium dichromate 1.0 mg/l	10	2	20
Potassium dichromate 1.0 mg/l	10	1	10
Potassium dichromate 1.4 mg/l	10	3	30
Potassium dichromate 1.4 mg/l	10	3	30
Potassium dichromate 1.8 mg/l	10	7	70
Potassium dichromate 1.8 mg/l	10	6	60
Potassium dichromate 2.0 mg/l	10	10	100
Potassium dichromate 2.0 mg/l	10	10	100

Conclusions:

EC50 (24h): 299 mg/l (nominal)

Executive summary:

The substance was tested for the acute toxicity to Daphnia rnagna, according to the OECD guideline 202, part I. The tests were run over a period of 24 hours and any concentration was assayed in duplicate.

The EC0 after 24 hours was determined to be 31.25 mg/l; the EC100 value was found to be higher than 1000 mg/l for 24 hours of exposure. The EC50 value was estimated to be (Logit-model) 299 mg/l for the respective exposure period.

The 95 %-confidence limits for the EC50 value of the respective exposure period were 136.7 - 783.3 mg/l.

In conclusion, test item showed no toxicity to daphnids.

The mortality observed with the control animals was 0 % after 24 hours. The tests were validated by testing potassium dichromate. The EC50 value determined for potassium dichromate after 24 hours was 1.484 mg/l.

Conclusion

EC50 (24h): 299 mg/l (nominal)

Description of key information

Not harmful/toxic to invertebrates

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

299 mg/L

Additional information

There are no information about the short-term potential toxicity of Basic Orange 064 to aquatic invertebrates, thus the available information on the structural analogue Similar Substance 02 have been taken into consideration; the read across approach can be considered as appropriate and suitable to assess the property under investigation (details about the approach are reported into the IUCLID section 13).

The Similar Substance 02 toxicity to Daphnia magna was tested according to the OECD guideline 202, part I. The tests were run over a period of 24 hours.

The EC0 was determined to be 31.25 mg/l, while the EC100 resulted to be higher than 1000 mg/l for 24 hours of exposure. The EC50 value was estimated to be (Logit-model) 299 mg/l for the respective exposure period. The 95 %-confidence limits for the EC50 value of the respective exposure period were 136.7 - 783.3 mg/l.