Disodium 6-hydroxy-5-[(2-methoxy-4-sulphonato-m-tolyl)azo]naphthalene-2-sulphonate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed according to the guideline.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 100 mg of the test substance in 100 ml of ADaM’s media. Achieving test concentrations of 1 g/L, respectively.

Test organisms (species):

Daphnia magna

Details on test organisms:

- Common name: Water flea
- Source: Own breeding of daphnia magna
- Food: No feeding after hatching

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

24 and 48 hrs

Hardness:

150.5 mg of CaCO3

Test temperature:

20±2

pH:

7.1

Nominal and measured concentrations:

100 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beaker
- Aeration: No aeration during experiment
- Material, size, headspace, fill volume: 25 ml of glass beaker filled with 20 ml media having headspace of 5 ml
- No. of organisms per vessel: 10 daphnids

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: No effects were observed

9.1. Immobility

Nominal Concentration (mg/l)	Number of Daphnids	Immobility
		0 h	24h	48h
Control	10	-	-	-
100	10	-	-	-

 

pH and oxygen content:

Nominal Concentration (mg/l)	Number of Daphnids	pH(mg/L)
		0 h	48h
Control	10	7.5	7.7
100	10	7.7	7.9

 

Nominal Concentration Number of			DO(mg/L)
(mg/l)		daphnids	0h	48h
Control		10	7.0	6.8
100		10	7.0	6.7

 

Test temperature:

Nominal Concentration Number of			Temparature
(mg/l)		daphnids	0h	48h
Control		10	21.2	21.5
100		10	21.2	21.5

Validity criteria fulfilled:

yes

Remarks:

1. In the control, including the control containing the solubilising agent, not more that 10 percent of the daphnids should have been immobilized. 2. The dissolved oxygen concentration at the end of the test should be 3 mg/l in control and test vessels

Conclusions:

Based on nominal concentration, experimental median effective Concentrations [EC50 (48 h)] for test material on test daphnia was found to be >100 mg/L.

Executive summary:

Daphnia sp., Acute Immobilization Test according to OECD Guideline 203 was conducted for determining toxicity of test material. The test solution was prepared by dissolving 100 mg of the test substance in 100 ml of ADaM’s media. Achieving test concentrations of 1 g/L, respectively.

The nominal concentration selected for the experiment was 100 mg/l and test Daphnia magna were exposed to these concentration for 48 hours. The median lethal concentration (EC50) for test material on Daphnia magna in a 48 hours study on the basis of immobilization effect was found to be >100 mg/l.

Thus, on the basis of this EC50 value and according to CLP criteria for aquatic classification of the substance, it is concluded that the substance, does not exhibit short term toxicity to Daphnia and can be considered to be not classified as per the CLP classification criteria.

Description of key information

Based on nominal concentration, experimental median effective Concentrations [EC50 (48 h)] for test material on test daphnia was found to be >100 mg/L. Thus, on the basis of this EC50 value and according to CLP criteria for aquatic classification of the substance, it is concluded that the substance, does not exhibit short term toxicity to Daphniaand can be considered to be not classified as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Based on the experimental data for the target as well as read-across analogues which are extracted by using mechanistic approach and functionally and structurally similar to the target chemical, toxicity of test chemical were determined on the basis of immobility of daphnia magna. The studies are summarized as below:

 

Daphnia sp., Acute Immobilization Test according to OECD Guideline 203 was conducted for determining toxicity of test material. The test solution was prepared by dissolving 100 mg of the test substance in 100 ml of ADaM’s media. Achieving test concentrations of 1 g/L, respectively.

The nominal concentration selected for the experiment was 100 mg/l and test Daphnia magna were exposed to this concentration for 48 hours. The median lethal concentration (EC50) for test material on Daphnia magna in a 48 hours study on the basis of immobilization effect was found to be >100 mg/l.

Thus, on the basis of this EC50 value and according to CLP criteria for aquatic classification of the substance, it is concluded that the substance, does not exhibit short term toxicity to Daphnia and can be considered to be not classified as per the CLP classification criteria.

 

Objective of second study was to determine the effect of test chemical on the mobility of daphnia magna. Test was conducted in accordance with OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). A limit test at sample concentration of 100 mg/L was performed. Effects on immobilisation were observed for 48 hours. The solution 100.0 mg/L was prepared by dissolving dark blue powder in reconstituted water. The solution was kept 5 min in ultrasonic bath. The median effective concentration (EC50) for the test substance on water flea, Daphnia magna was determined to be >100 mg/L on the basis of mobiity inhibition effects in a 48 hour study as EC50 was observed at the limit test concentration 100 mg/l. Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance does not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna) and thus not classified as per the CLP classification criteria.

 

 

Again to support both the studies, another study was performed to determine the toxicity of test chemical on D. magna for 48 hours in a static system. Daphnids were exposed to test chemical in 50 ml beakers in a volume of 25 ml of liquid solution containing both the chemical and media as specified in OECD 202. The nominal concentrations used were 100 mg/L (limit test).

The IC50 was defined as a concentration that immobilizes 50% of the exposed D. magna. Eight percent immobilization in D. magna was observed after 48 hours of exposure to 100 mg/L of test chemical. The EC50 was therefore estimated to be >100 mg/L.

 

Based on the EC50 value, it can be concluded that the chemical was nontoxic and was considered to be not classified as per CLP classification criteria.