1-[[2-methyl-4-[(2-methylphenyl)azo]phenyl]azo]-N-tridecylnaphthalen-2-amine

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:

Nov 2017 - April 2018

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:

yes

Remarks:

see below

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

see below

Principles of method if other than guideline:

The study was performed without analytical determination of the test substance concentrations. For the analytical determination of the test substance concentration, no suitable analytical method was found. As the concentrations could not be quantified by analytical methods, the effect concentrations are expressed based on the nominal concentrations.
This deviation was considered not to have adversely affecting the results or integrity of the study.

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION OF TEST SOLUTION

Because the test item is very poorly soluble in water, a test solution were prepared using a saturated solution method according to the Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, OECD No. 23.

A saturated Test Item solution (nominal loading rate of 100 mg/L) was prepared by dispersing/dissolving the amount of Test Item into the test medium (ISO Medium) one day before the start of the experiment. This solution was shaken for approximately 24 hours at approximately 30°C (Day -2) and then was equilibrated for approximately 24 hours at approximately 20°C (Day -1). The non-dissolved test materials were removed by filtration through a fine (0.22 µm) filter to give the 100% saturated solution. As a limit test was carried out, further dilution of this stock solution was not performed.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species and strain: Daphnia magna
Source: Szent István University, Department of Aquaculture 2100 Gödöllő, Páter Károly u. 1. – Hungary
Justification of strain: Daphnia magna is the standard species of the acute immobilisation test.
Number of animals: There were 20 animals in test and control groups respectively, divided into 4 replicates
(5 animals / replicate)
Age of the animals: They were less than 24 h old at the beginning of the test
Acclimatization: There was no acclimatization because the water used was similar to the culture water

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

The reconstituted water (ISO medium) had a total hardness of 248 mg/L (as CaCO3).

Test temperature:

The water temperature was measured at the start of the test and 24-hour intervals thereafter in each test vessel. The test temperature was in the range of 20.3 – 20.6°C measured in the test vessels.
The additionally measured temperature in the climate chamber was between 19.8 and 20.9°C.

pH:

The pH of the test solution was not adjusted and not varied by more than 1.5 units in any one test. The pH was measured at the start and at the end of the experiment in each test vessel and was in the range of 7.03 – 7.28.

Dissolved oxygen:

The dissolved oxygen concentration was measured in each test vessel at the start and at the end of the experiment and was in the range of 7.7– 8.8 mg/L.

Nominal and measured concentrations:

- Nominal concentrations: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass Beakers
- Material, size, headspace, fill volume: 50 mL per beaker
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: At least 5 mL of test solution per individual
The animals were not fed during the test.

TEST MEDIUM / WATER PARAMETERS
-Reconstituted water (ISO medium, according to OECD 202) was used as dilution water for both the range finding and definitive tests. The same composition of reconstituted water was used for the tests and for breeding the test animals.
The composition of the reconstituted water and the chemicals used are recorded

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: The test was carried out in 16-hour light and 8-hour dark cycle.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
The immobility or mortality of the Daphnia was determined by visual observation 24 and 48 hours after the start of the test. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker are considered to be immobile. The number of immobilised animals and the percentage of immobility were determined at 24 and 48 hours.
The water temperature was measured daily, the oxygen concentrations and pH of the control and the test solution were measured at the beginning and at the end of the experiment.


Untreated Control
The dilution water (ISO-medium) was used without of addition of the Test Item.


Reference Control
For the evaluation of the quality of the Daphnia clone and the experimental conditions, Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.
The date of the last study (Study Code: 17/367-023DA) with reference item Potassium dichromate (batch no.: A0345704) is: 06-07 December 2017. The 24h EC50: 0.65 mg/L, (95 % confidence limits: 0.61 – 0.70 mg/L).

RANGE-FINDING STUDY
- Test concentrations: 100, 60, 40, 20 and 10 mg/L
- A toxic response was not observed during the preliminary concentration range-finding test therefore, a limit test was carried out using only one test concentration at 100% saturated solution and one control group in a static system.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

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

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

There was no immobilisation observed.Test Item had no toxic effect at saturation on Daphnia; the EC50 results and the LOEC are higher than the solubility level of the Test Item in the test medium.

Results with reference substance (positive control):

For the evaluation of the quality of the Daphnia clone and the experimental conditions, Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.
The date of the last study (Study Code: 17/367-023DA) with reference item Potassium dichromate (batch no.: A0345704) is: 06-07 December 2017. The 24h EC50: 0.65 mg/L, (95 % confidence limits: 0.61 – 0.70 mg/L).

Reported statistics and error estimates:

No statistical analysis was performed because of the lack of toxic effects.
The EC50, NOEC, LOEC and EC100 values were determined directly from the raw data.

Immobilisation of the test animals

Test group	Number of animals	Number of immobilised animals
		24 h	48 h
Control	5	0	0
	5	0	0
	5	0	0
	5	0	0
100% saturated solution	5	0	0
	5	0	0
	5	0	0
	5	0	0

 

 

Validity criteria fulfilled:

yes

Remarks:

There was no immobilisation in the controls and the dissolved oxygen content remained above 3 mg/L.

Conclusions:

Under the conditions of this study, the 48 hour EC50 was determined to be >100 mg/L and the 48 hour NOEC was 100 mg/L.

Executive summary:

The test substance, Solvent Red 19T, was investigated for acute toxicity to Daphnia magna under GLP conditions.

The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test, Council Regulation (EC) No. 440/2008, published in O.J. L 142, 2008 and OECD Test Guideline No 202, Daphnia sp., Acute Immobilisation Test, Adopted: April 13, 2004.

In a preliminary study, 10 daphnids per concentration were exposed the test material at nominal concentrations of 0.1, 1, 10 and 100 mg/L under semi-static conditions.

The nominal concentrations were used for all evaluations and results. The study was performed without analytical determination of test substance concentrations because no suitable analytical method was found.

Since the test substance is poorly soluble in dilution water at the concentrations needed for the test, saturated solutions of the test substance in dilution water were prepared by adding measured amounts of the test substance to the dilution water.

As no toxicity of the test substance was found in preliminary test, a limit test was carried out using onlyone test concentration.(100 mg/L )

Under the conditions of this study, the 48 hour EC50 was determined to be >100 mg/L and the 48 hour NOEC was 100 mg/L. The 48 hour EC100 was >100 mg/L.

Description of key information

The 48 hour EC50 was determined to be >100 mg/L and the 48 hour NOEC was 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The test substance, Solvent Red 19T, was investigated for acute toxicity to Daphnia magna under GLP conditions.

The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test, Council Regulation (EC) No. 440/2008, published in O.J. L 142, 2008 and OECD Test Guideline No 202, Daphnia sp., Acute Immobilisation Test, Adopted: April 13, 2004.

In a preliminary study, 10 daphnids per concentration were exposed the test material at nominal concentrations of 0.1, 1, 10 and 100 mg/L under semi-static conditions.

The nominal concentrations were used for all evaluations and results. The study was performed without analytical determination of test substance concentrations because no suitable analytical method was found.

Since the test substance is poorly soluble in dilution water at the concentrations needed for the test, saturated solutions of the test substance in dilution water were prepared by adding measured amounts of the test substance to the dilution water.

As no toxicity of the test substance was found in preliminary test, a limit test was carried out using only one test concentration.(100 mg/L )

Under the conditions of this study, the 48 hour EC50 was determined to be >100 mg/L and the 48 hour NOEC was 100 mg/L. The 48 hour EC100 was >100 mg/L.