Manganese-(II)-hexacyanomanganate (II) sodium salts

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Manganese-(II)-hexacyanomanganate (II) sodium salts

EC Number:

847-971-4

Cas Number:

2363126-59-2

Molecular formula:

NaxMny[Mn(CN)6]z X = 1.2-1.4; Y = 1.0; Z = 0.8-0.85

IUPAC Name:

Manganese-(II)-hexacyanomanganate (II) sodium salts

impurity 1

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Oxidane

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

See section on test item details

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.15 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

0.27 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 3

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.21 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Daphnia magna were exposed to the test item in a valid study, showing signs of toxicity below the saturation limit. The test item is considered to be hazardous to daphnia magna at reported concentrations.

Executive summary:

A study was performed to assess the acute toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

Preliminary solubility work conducted indicated that it was not possible to obtain a testable solution of the test item using traditional methods of preparation e.g. ultrasonication and high shear mixing. A preliminary media preparation trial indicated that a dissolved test item concentration of approximately 37 mg/L was obtained from a slow-stir saturated solution method of preparation indicating this to be the limit of water solubility of this item under test conditions.

Following a preliminary range-finding test, 20 daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test item at nominal concentrations of 0.10, 0.18, 0.32, 0.58 and 1.0% v/v saturated solution for 48 hours at a temperature of approximately 10°C to 22°C under static test conditions. The test item solutions were prepared by stirring an excess (100 mg/L (anhydrous content)) of test item in test water via magnetic stirrer using a stirring rate such that a vortex was formed to give a dimple at the water surface for 1 hour. After the stirring period any undissolved test item was removed by filtration through a 0.2μm Gelman Acrocap filter (the first approximate 500 mL used to pre-condition the filter was discarded), to give a 100% v/v saturated solution of the test item. This saturated solution was then further diluted to give a 10% v/v saturated solution of the test item. A series of dilutions was then made from this saturated solution to give stock solutions of 1.0, 0.58 and 0.32% v/v

saturated solutions. Further dilutions were made from the 1.0% v/v saturated solution to give stock solutions of 0.18 and 0.10% v/v saturated solution.

Immobilization and any adverse reactions to exposure were recorded after 24 and 48 hours. Chemical analysis of the fresh test preparations at 0 hours showed measured test concentrations to range from less than the limit of quantification (LOQ) determined to be 0.013 mg/L as Manganese which is equivalent to 0.043 mg/L (as test item) to 0.27 mg/L. Analysis of the old test preparations at 48 hours showed measured concentrations to range from less than the LOQ to 0.26 mg/L. There was no significant change in the measured concentrations at 48 hours and so the results are based on the 0-Hour measured test concentrations. Where a measured concentration of less than the LOQ of the analytical method was determined, a value of half the LOQ was utilized.

Exposure ofDaphnia magna to the test item gave the following results based on the 0-Hour measured test concentrations:

 

Time Point (Hours)	EC50 (mg/L)	95% Confidence Limits (mg/L)	No Observed Effect Concentration (NOEC) (mg/L)	Lowest Observed Effect Concentration (LOEC) (mg/L)
48	0.21	0.032 - 1.4	0.15	0.27