Strontium 3-hydroxy-4-[(1-sulfonato-2-naphthyl)azo]-2- naphthoate 5/2 hydrate

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:

21 January 2008- 23 January 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

The water solubility of the test substance at 19.9°C ± 0.6°C was < 7 x 10·5 g/1, using the column elution method. R507-2 concentrations were not stable during freezing and thawing of samples. Consequently, samples were analysed on the day of sampling (NOTOX Project 486300).

Vehicle:

not specified

Details on test solutions:

The standard test procedures required generation of test solutions, which should contain completely dissolved test substance concentrations or stable and homogeneous mixtures or dispersions. The testing of concentrations that disturb the test system should be prevented (e.g. film of the test substance on the water surface).

The batch of R507-2 tested was a red powder with a purity 96.4% and not soluble in test medium at the loading rate tested.

Preparation of test solutions started with loading rates of 100 mg/I applying a 5 to 6-minute treatment period with ultrasonic waves followed by 3 days of magnetic stirring. The resulting red dispersion contained undissolved particles and a floating layer and was consequently filtered through a 0.45 µm membrane filter (Schleicher & Schuell, RC55) to remove the larger undissolved particles. The lower test concentration was prepared by dilution of the filtrate in test medium. The final test solutions were all clear and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by acyclical parthenogenesis under specified breeding conditions.
- Justification for species other than prescribed by test guideline: This system has been selected as an internationally accepted invertebrate species.
- Source: In-house laboratory culture with a known history.
- Age of parental stock (mean and range, SD): parental daphnids of more than two weeks old.
- Feeding during test
- Food type: Daily, a suspension of fresh water algae.

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Test temperature:

The temperature of the test medium was 18.8 - 19.8 °C

pH:

6.0-8.5

Nominal and measured concentrations:

Analysis of the samples taken from the filtrate prepared at 100 mg/I showed that the measured concentrations were below the limit of detection, i.e. < 0.02 mg/L The filter residue was identified as R507-2.

Details on test conditions:

TEST SYSTEM
- Test vessel:100 ml, all-glass
- Aeration: No aeration of the test solutions.
- Renewal rate of test solution (frequency/flow rate):Static test.
- No. of organisms per vessel:5 per vessel containing 80 ml of test solution




OTHER TEST CONDITIONS

- Light intensity:16 hours photoperiod daily (low light intensity 9 lux)

These test conditions remained within the limits prescribed by the protocol (pH: 6.0-8.5, not varying by more than 1 unit; oxygen: 3 mg/I at the end of the test).

The temperature of the test medium was 20.0°C at the start of the test. The temperature continuously measured in a temperature control vessel varied between 18.8 and 19.8°C during the test, and complied with the requirements as laid down in the protocol (18-22°C, constant within 2°C).

Reference substance (positive control):

yes

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mortality

Details on results:

No immobile daphnia were observed in any of the groups tested.

Results with reference substance (positive control):

The reference test was carried out to check the sensitivity of the test system as used by NOTOX. Daphnia were exposed for a maximum of 48 hours to K2Cr20 7 concentrations of 0.10, 0.18, 0.32, 0.56, 1.0 and 1.8 mg/I and to a blank control. Twenty daphnia were exposed per concentration.

The actual responses in this reference test with K2Cr20 7 are within the ranges of the expected responses at the different concentrations. Hence, the sensitivity of this batch of D. magna was in agreement with the historical data collected at NOTOX.
The 24h-EC50 was 0.76 mg/I with a 95% confidence interval between 0.67 and 0.90 mg/I. The 48h-EC50 was 0.51 mg/I with a 95% confidence interval between 0.47 and 0.58 mg/I. The raw data from this study are kept in the NOTOX archives. The test described above was
performed under GLP with a QA-check.

Acute immobilisation of daphnids after 24 and 48 hours in the final test

 

Test group* R507-2 (%filtrate)	Vessel number	Number Daphnia exposed	Response at 24 h		Response at 48 h
			number	Total %	number	Total %
Control	AB C D	5	0	0	0	0
		5	0		0
		5	0		0
		5	0		0
10	A B	5	0	0	0	0
		5	0 (5)		0
100	AB C D	5	0	0	0	0
		5	0		0 (1)
		5	0 (1)		0
		5	0		0

Table 2 shows the effect parameters based on loading rates.

 

Table 2           Effect parameters

 

Parameter	Test group* R507-2 (mg/I)
NOEC	100
24,48h-ECso	>100

*Test group represents a 0.45 µm filtered solution prepared at a loading rate of 100mg/I.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study R507-2 did not induce acute immobilisation when exposed to a 0.45 µm filtered solution prepared at a loading rate of 100 mg/I (NOEC).

The 48h-EC50 exceeded the maximum solubility in test medium, i.e. the concentration present in a 0.45 µm filtered solution prepared at a loading rate of 100 mg/I. Analyses showed that the measured concentration was below 0.02 mg/I.

Executive summary:

Acute Toxicity Study in Daphnia magna with R507-2.

 

The study procedures described in this report were based on the OECD guideline No. 202, 2004. In addition, the procedures were designed to meet the test methods of the EEC directive 92/69, Part C.2, 1992, the ISO International Standard 6341, 1996 and the OECD series on testing and assessment number 23, 2000.

 

The batch of R507-2 tested was a red powder with a purity 96.4% and not soluble in test medium at the loading rate tested. The water solubility was determined to be less than 0.07 mg/I.

 

Based on the poor solubility in water it was decided to start directly with a final test. Twenty daphnia per test group (4 vessels, 5 per vessel) were exposed to a control and a 0.45 µm filtered solution prepared at a loading rate of 100 mg/I. In addition, 10 daphnia were exposed to a ten-fold dilution of the filtrate. The total test period was 48 hours and samples for analytical confirmation of actual concentrations were taken at the start and the end of the test period.

 

Analysis of the samples taken from the filtrate prepared at 100 mg/I showed that the measured concentrations were below the limit of detection, i.e. < 0.02 mg/I. The filter residue was identified as R507-2.

 

The study met the acceptability criteria prescribed by the protocol and was considered valid.

 

R507-2 did not induce acute immobilisation when exposed to a 0.45 µm filtered solution prepared at a loading rate of 100 mg/I (NOEC).

 

The 48h-EC50 exceeded the maximum solubility in test medium, i.e.the concentration present in a 0.45 µm filtered solution prepared at a loading rate of 100 mg/I. Analyses showed that the measured concentration was below 0.02 mg/I.

Description of key information

Acute Toxicity Study in Daphnia magnawith R507-2.

 

The study procedures described in this report were based on the OECD guideline No. 202, 2004. In addition, the procedures were designed to meet the test methods of the EEC directive 92/69, Part C.2, 1992, the ISO International Standard 6341, 1996 and the OECD series on testing and assessment number 23, 2000.

 

The batch of R507-2 tested was a red powder with a purity 96.4% and not soluble in test medium at the loading rate tested. The water solubility was determined to be less than 0.07 mg/I.

 

Based on the poor solubility in water it was decided to start directly with a final test. Twenty daphnia per test group (4 vessels, 5 per vessel) were exposed to a control and a 0.45 µm filtered solution prepared at a loading rate of 100 mg/I. In addition, 10 daphnia were exposed to a ten-fold dilution of the filtrate. The total test period was 48 hours and samples for analytical confirmation of actual concentrations were taken at the start and the end of the test period.

 

Analysis of the samples taken from the filtrate prepared at 100 mg/I showed that the measured concentrations were below the limit of detection, i.e.<0.02 mg/I. The filter residue was identified as R507-2.

 

The study met the acceptability criteria prescribed by the protocol and was considered valid.

 

R507-2 did not induce acute immobilisation when exposed to a 0.45 µm filtered solution prepared at a loading rate of 100 mg/I (NOEC).

 

The 48h-EC50 exceeded the maximum solubility in test medium, i.e.the concentration present in a 0.45 µm filtered solution prepared at a loading rate of 100 mg/I. Analyses showed that the measuredconcentrationwasbelow0.02mg/I.