Disodium-3,3´-{Oxybis[2,1-ethanediyloxy(1-oxo-2,1-ethanediyl)imino]}bis(2,4,6-triiodobenzoate)

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:

Oct 2002 - Nov 2002

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

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Schering AG, Bergkamen, Gennany (Batch No.61703003)
- Purity: 99.5 %

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Stability under test conditions: Stable according to re-analysis no. 04205349.
- Solubility and stability of the test substance in the solvent/vehicle: S20•c> 546 g/L (according to Schering report A09525)

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Final dilution of a dissolved solid, stock liquid: Nominal concentration of the unfiltered solution: 1111 mg.IL.


OTHER SPECIFICS:
Vapour pressure: P25 < 10·3 Pa (according to Schering report A07301)
Hydrolytical stability:Hydrolytical stability:: t1/2 > 1 year at 25°C (according to Schering report A08129)

Analytical monitoring:

yes

Details on sampling:

Concentration analysis by TOC was performed in samples taken at O and 48 hours after start of exposure. The analytical results gave mean concentrations of 60.1 mg/L (1: 16 dilution),
135.6 mg/L (1:8 dilution) 242.7 mg/L (1:4 dilution), 475.8 mg/L (1:2 solution), and 1011.0 mg/L (highest concentration). The measured values agreed with the nominal, therefore the nominal values are used for further evaluation .

Vehicle:

yes

Remarks:

The substance was dissolved in tap water

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

The highest concentration was 1000 mg/L (nominal). In a previous limit test three daphnids were immobilized at 100 mg/L and one in the control goup. In order to assess, whether this was unambiguously a compound related effect, in this definitive test a solution of 1000 mg/1 served as the highest test concentration.

For the stock solution 1111 mg iotroxic acid, di sodium salt were dissolved in 1000 mL. This solution was used as the highest test concentration (after dilution with the introduced test organisms as explained in section 5.1.2.2). Aliquots of the solution were further diluted 1 :2, 1 :4, 1: 8 and 1: 16 with tap water in order to prepare the appropriate test concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
Specification: Daphnia magna Straus, Cladocera, Phyllopoda
Source: Schering AG, Exp. Toxicology, Berlin, Germany
Age: 0-24 hours
Holding: Parent animals were kept in glass vessels in water of the same quality and temperature as under experimental conditions. The animals were continuously fed with a laboratory culture of microalgae, e.g. Chlorella vulgaris.
Water:Normal tap water was used as dilution water, not polluted with harmful concentrations of chlorine and organochlorine compounds, based on quarterly measurements. Specific characteristics of the dilution water are given in the annex.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

The temperature was between 20.7 and 21.3. This was in the accepted range.

pH:

The pH varied between 7.0 at the beginning and 8.5 at the end of the test. This was slightly outside the required range, but had no effect on the validity of the test.

Dissolved oxygen:

The range of the measured dissolved oxygen was between 8.6 and 8.8 mg/L. This was in the accepted range.

Nominal and measured concentrations:

The analytical results gave mean concentrations of 60.1 mg/L (1: 16 dilution), 135.6 mg/L (1:8 dilution) 242.7 mg/L (1:4 dilution), 475.8 mg/L (1:2 solution), and 1011.0 mg/L (highest concentration). The measured values agreed with the nominal, therefore the nominal values are used for further evaluation .

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: immobilization

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: immobilization

Cumulative immobilization of Daphnia magna after exposure to iotroxic acid, disodium salt
Measured concentration of iotroxic acid, disodium salt (mg/L)	Total no. of Daphnia	No. of immobilized Daphnia
0 Control (tap water)	20	0	0
63	20	0	0
125	20	0	0
250	20	0	0
500	20	0	0
1000	20	0	0

Validity criteria fulfilled:

yes

Conclusions:

The 24 and 48 hours EC 50 of iotroxic acid, disodiurn salt to Daphnia rnagna was higher than 1000 mg/L.

Executive summary:

The 48 hr-acute toxicity of iotroxic acid, disodium salt to Daphnia magna was studied under static conditions.  Test species were exposed to control and test chemical at measured concentration of 0. 63, 125, 250, 500, 1000 mg a.i./L for 48 hrs.  Immobilization and visual abnormalities were recorded at 24 and 48 hours.  The 24 hour EC₅₀ was > 1000 mg a.i./L.  The 48 hour EC₅₀ was > 1000 mg a.i./L.  The 48 hr NOEL based on immobilization was > 1000 mg a.i./L.  No Daphnia was immobilized, neither in the test nor control solution.

 

Based on the results of this study, iotroxic acid, disodium salt would be not be classified as acute toxicity study with freshwater invertebrates.

 

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

 

Test Organism Age: Juvenile Daphnia magna

Test Type: Static

 

24 hr EC₅₀:  >1000 mg a.i./L

48 hr EC₅₀:  >1000 mg a.i./L

48 hr NOEL:  >1000 mg a.i./L              

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1 000 mg/L