Dimanganese trioxide

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

For details on the read across justification refer to the read across statement in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

I

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: v/v saturated solution

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: % v/v saturated solution

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: % v/v saturated solution

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test material on the growth of Desmodesmus subspicatus has been investigated and gave EC50 values of greater than 100% v/v saturated solution. Correspondingly the No Observed Effect Concentration (NOEC) was 100% v/v saturated solution. This study showed that there were no toxic effects at saturation.

Executive summary:

A study was performed to assess the effect of the test material on the growth of the green alga Desmodesmus subspicatus. The method followed that described in the OECD Guidelines for Testing of Chemicals (2006) No 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test" referenced as Method C.3 of Commission Regulation (EC) No 440/2008.

Pre-study solubility work conducted indicated that it was not possible to obtain a testable solution of the test material using traditional methods of preparation e.g. ultrasonication and high shear mixing. It was therefore considered that the most appropriate method of preparation for the test material was as a saturated solution.

Following a preliminary range-finding test, Desmodesmus subspicatus was exposed to a solution of the test material at a nominal test concentration of 100% v/v saturated solution (six replicate flasks) for 72 hours, under constant illumination and shaking at a temperature of 24 ± 1°C. Samples of the algal populations were removed daily and cell concentrations determined for each control and treatment group, using a Coulter®Multisizer Particle Counter.

Under the conditions of the study, exposure of Desmodesmus subspicatus to the test material gave EC50 values of greater than 100% v/v saturated solution and correspondingly the No Observed Effect Concentration was 100% v/v saturated solution. Therefore, under the conditions of the study there were no toxic effects up to the limit of solubility of the test material in the test medium.

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

Description of key information

Under the conditions of the valid study reported by Vryenhoef & Mullee (2010), the effect of manganese dioxide on the growth of Desmodesmus subspicatus has been investigated and gave EC50 values of greater than 100% v/v saturated solution. Correspondingly the No Observed Effect Concentration (NOEC) was 100% v/v saturated solution. This study showed that there were no toxic effects at saturation.This information is used in a read-across approach in the assessment of the target substance dimanganese trioxide.

Additional information

The information on manganese dioxide is used in a read-across approach in the assessment of dimanganese trioxide.

For details on the read across justification refer to the read across statement in IUCLID section 13.