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

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020-04-06 til 2020-07-22

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Version / remarks:

2011

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 "Test material information"

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: saturated solution measured to be ca. 19.7 mg/L test item equivalent, serial dilution
- Sampling method: 0 - 24 - 72 hrs
- Sample storage conditions before analysis: not applciable, immediate analysis

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume:
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):
- Initial cells density:
- Control end cells density:
- No. of organisms per vessel:
- No. of vessels per concentration (replicates):
- No. of vessels per control (replicates):
- No. of vessels per vehicle control (replicates):

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
- Total organic carbon:
- Particulate matter:
- Metals:
- Pesticides:
- Chlorine:
- Alkalinity:
- Ca/mg ratio:
- Conductivity:
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: no
- Photoperiod: 24/24
- Light intensity and quality:
- Salinity (for marine algae): not applicable

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Coulter® Multisizer Particle Counter, haemocytometer and light microscope.
- Chlorophyll measurement:
- Other:

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3,16
- Justification for using less concentrations than requested by guideline:
- Range finding study: yes
- Test concentrations: 0.0031, 0.010, 0.031, 0.10 and 0.31% v/v saturated solution
- Results used to determine the conditions for the definitive study: Growth rate

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

ca. 0.199 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

LOELR

Effect conc.:

0.617 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.219 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no
- Unusual cell shape: no
- Colour differences: no
- Flocculation: not reported
- Adherence to test vessels:
- Aggregation of algal cells:
- Other:
- Any stimulation of growth found in any treatment:
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:
- Effect concentrations exceeding solubility of substance in test medium:

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item has been tested as harmful to aquatic algae with a calculated EC50r of 0,22 mg/L based on percentage of measured saturated stock slutions and on base of an elemental analysis.