Iotroxic acid

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

Justification for type of information:

In an aqueous environment, the iotroxic acid separates from the disodium salt immediately. Therefore, tests conducted with disodium salt in aqueous medium are representative for the toxicity of iotroxic azide.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

Immobilization

Validity criteria fulfilled:

yes

Conclusions:

No Daphnia was immoblized, neither in the test nor control solution.
The measured values are within the limit (<= 20% variation of the nominal) required by the OECD guideline 202.
The 48-hr EC50 of iotroxic acid, disodium salt to Daphnia magna is higher than 1000 mg/L (nominal).

Executive summary:

The 48 hr-acute toxicity of iotroxic acid, disodium salt to Daphnia magna Straus was studied under static conditions. Daphnids were exposed to a control containing no test substance, and iotroxic acid, disodium salt (purity 99.5%) at nominal concentration of 63, 125, 250, 500 and 1000 mg/L (mean concentrations of 60.1, 135.6, 242.7, 475,8 and 1011 mg/L) for 48 hr. Immobilization was observed daily. 

The 48 – hr EC50 was higher than 1000 mg/L (nominal). 

 

Based on the results of this study, iotroxic acid, disodium salt would not be classified as toxic to D. magna Straus in accordance with the classification system of the Regulation (EC) No 1272/2008 (CLP).  

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

 

Results Synopsis

 

Test Organism Age (e.g. 1st instar): < 24 hr

Test Type: Static

48 – hr EC50   > 1000 mg a.i./L, nominal

Endpoint(s) Effected:  mortality, immobility

This information is used in a read-across approach in the assessment of the target substance.

Description of key information

In an acute immobilization test with Daphnia magna (STRAUS) according to OECD guideline 202, EC guideline Part 2 -Testing Methods, Part C.2 and GLP, the toxic effects of the test item to aquatic invertebrates were determined after 48 h exposure under static conditions.

The 48-h EC₅₀was determined to be higher than 1000 mg/L (nominal). The nominal concentration was verified analytically.

Consequently, no hazard is identified.

Additional information

This information is used in a read-across approach in the assessment of the target substance.

No data are available for iotroxic acid (target substance). Thus, iotroxic acid, disodium salt (source substance) is used to assess the aquatic toxicity of iotroxic acid in a read-across approach.

Data describing the acute aquatic toxicity of iotroxic acid is based on read-across from iotroxic acid, disodium salt. In aqueous solution disodium salt disassociates to iotroxic acid.