Iron(III) manganese(II) hexacyanoferrate(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

Reliability:

1 (reliable without restriction)

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 201 (Alga, Growth Inhibition Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Iron(III) manganese(II) hexacyanoferrate(II) sodium salts

EC Number:

847-973-5

Cas Number:

2363126-51-4

Molecular formula:

NaxMny1Fey2[Fe(CN)6]z X = 1-2; Y1 = 0.5-0.9; Y2 = 0.1-0.5; Z = 0.67-1.0

IUPAC Name:

Iron(III) manganese(II) hexacyanoferrate(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:

Water

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

OECD 29 follwed,
Test medium was prepared according to OECD TG 29, difficult substances, by pouring the substance into the medium (250 mg/2 L culture medium) , follwed by stirring for 3 hours and filtration through a 0.2 Gelman Acrocap filter. From the saturated stock solution the test concentrations have been prepoared by serial dilution.
Nominal test concentration were 0.010, 0.032, 0.10, 0.32 and 1.0% v/v of the saturated solution.

Test organisms

Test organisms (species):

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

Study design

Test type:

static

Water media type:

freshwater

Remarks:

modified ISO medium

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

no

Test conditions

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.016 mg/L

Nominal / measured:

nominal

Conc. based on:

element (dissolved fraction)

Remarks:

iron

Basis for effect:

growth rate

Remarks on result:

other: see section "Details on results"

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.049 mg/L

Nominal / measured:

nominal

Conc. based on:

element (dissolved fraction)

Remarks:

iron

Basis for effect:

growth rate

Remarks on result:

other: see section "Details on results"

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.26 mg/L

Nominal / measured:

nominal

Conc. based on:

element (dissolved fraction)

Remarks:

iron

Basis for effect:

growth rate

Remarks on result:

other: see section "Details on results"

Details on results:

Analysis of the test preparations at 0, 24, 48 and 72 hours showed measured test concentrations of less than the Limit of Quantification (LOQ) of the analytical method, determined to be 0.10 mg/L (as iron). This does not infer that there was no test item in solution, only that which may have been present, was at a concentration below the LOQ.

Analysis of the stock solutions (10 and 100% v/v saturated solution) showed measured concentrations to be 0.81 and 8.7 mg/L (as iron and as 4.6 and 49 mg/L as test item) respectively. Proving that the test item was in solution and could be detected at the higher concentrations from which the lower test concentrations were produced from, hence it can be concluded that Raphidocelis subcapitata was exposed to the test item.

Therefore, the test medium was prepared according to OECD TG 29, difficult substances, by pouring the substance into the medium (250 mg/2 L culture medium) , follwed by stirring for 3 hours and filtration through a 0.2 Gelman Acrocap filter. From the saturated stock solution the test concentrations have been prepoared by serial dilution.

In addition to the low solubility, the test item is prone to hydrolyse fast, and the metal-ion-cyanide complex breaks apart. Therefore, the presented values in the table which are are recalculated from the nominal loading rate do not necessairly reflect the actual concentration of the test item in water.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item on the growth of Raphidocelis subcapitata has been investigated over a 72 hour period in a valid OECD TG 201 test. The presented values are recalculated based on the nominal concentration elemental analysis, which does not necessarily reflect the actual concentration of the test item, but rather reflects the hydrolysis product from the parental substance.