Manganese carbonate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.008 mg/L

Assessment factor:

50

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.011 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.001 mg/L

Assessment factor:

500

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

100 mg/L

Assessment factor:

10

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

8.18 mg/kg sediment dw

Assessment factor:

50

Extrapolation method:

assessment factor

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.81 mg/kg sediment dw

Assessment factor:

500

Extrapolation method:

assessment factor

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

8.15 mg/kg soil dw

Assessment factor:

50

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

insufficient hazard data available (further information necessary)

Additional information

PNEC values The aquatic PNEC values calculated above for freshwater, marine water and intermittent release are calculated based on the NOEC of 0.41 mg/L taken from the algal growth inhibition study on MnO. This can be considered a worst-case option as the newly-available algal study on MnCO3 itself has a higher NOEC of 0.69 mg/L.

PNEC aquatic values: 

It should be noted that these values are comparable to the background concentration of manganese in European environments (15.9 µg Mn/L in surface water; “Probabilistic Distribution of Manganese in European Surface Water, Sediment and Soil and Derivation of Predicted Environmental Concentrations (PEC)”, Parametrix, 2009 and supported by GEMAS data) and hence have limited relevance for assessment of any potential risk from MnCO₃.

 

Sediment

No experimental data on sediment toxicity exist. The data are not required as the hazard assessment performed during the chemical safety assessment concludes that the substance is not classified and is of no immediate concern to the environment.PNEC sediment is calculated by the equilibrium partitioning method.

PNEC sediment:

It should be noted that this value is considerably lower than the background concentration of manganese in European environments (452 mg/kg in sediment; “Probabilistic Distribution of Manganese in European Surface Water, Sediment and Soil and Derivation of Predicted Environmental Concentrations (PEC)”, Parametrix, 2009 and supported by GEMAS data) and hence has little relevance for assessment of any potential risk from MnCO₃.

Terrestrial

No experimental data on terrestrial toxicity exist. The data are not required as the hazard assessment performed during the chemical safety assessment concludes that the substance is not classified and is of no immediate concern to the environment.PNEC soil is calculated by the equilibrium partitioning method.

 

PNEC soil:

MnCO₃is used in fertilizer preparations for crops/soils and hence high localised concentrations in soil would not be expected to have adverse effects in the soil environment. It should also be noted that this value is considerably lower than the background concentration of manganese in European environments (428.6 mg/kg in soil; “Probabilistic Distribution of Manganese in European Surface Water, Sediment and Soil and Derivation of Predicted Environmental Concentrations (PEC)”, Parametrix, 2009 and supported by GEMAS data) and hence has little relevance for assessment of any potential risk from MnCO₃.

 

STP

No effects on sewage sludge were observed in a standard 3hr study on MnCO₃. Hence the NOEC for MnCO₃ is 1000 mg/L.

 

Conclusion on classification

According to the 2nd ATP to the CLP Regulation (EU) No 286/2011, the methodology for determining the environmental classification of metal compounds that have limited solubility, is based on the assumption that the ecotoxicological effects are determined by the fraction of dissolved metal. On this basis, relevant ecotoxicological information generated with a soluble metal compound (expressed in terms of mg metal ion per litre) are compared with the level of metal ion released from the sparingly soluble metal compound under investigation (as determined during transformation/dissolution protocol testing).

The relevant ecotoxicological values (environmental reference values, ERV) for manganese were established by considering the database of available studies conducted with soluble manganese compounds (i.e. manganese dichloride, manganese sulphate, and manganese nitrate). The database was refined through application of suitable relevance and reliability criteria. From the resulting studies, the short term toxicity study with the lowest L(E)C50 was selected as the acute ERV for manganese (3.2 mg Mn/L;Davies & Brinkman, 1998 - Rainbow trout study with MnSO4), and the long term toxicity study with the lowest NOEC was selected as the chronic ERV for manganese (0.55 mg Mn/L;Davies & Brinkman, 1998 - Brook trout study with MnSO4). Both studies were conducted on standard species, and were assessed to be of adequate relevance and reliability for use in hazard determination of manganese. Summaries of these studies are included in this dataset.

The acute and chronic ERV values were compared to the levels of Mn release, as determined through transformation/dissolution protocol testing with MnCO3 (Rodriguez, 2010). During the transformation/dissolution protocol test with MnCO3, at initial test substance loading rates of 1, 10 and 100 mg/L, the level of manganese measured in the pH 6 media, following a 7 day exposure period, were 392.7, 3025.8 and 9208.2 µg/L, respectively. The level of manganese measured in the pH 6 media following 28 days exposure, at the 1 mg/L test material loading rate, was 338.4 µg/L. Since the level of Mn release following a 7 day exposure of MnCO3 to environmentally relevant water, at all three loading rates, was lower than the acute ERV, MnCO3 does not require classification in terms of acute aquatic toxicity. Since the level of Mn release following a 28 day exposure of MnCO3 to environmentally relevant water, at a loading rate of 1 mg/L, was lower than the chronic ERV, MnCO3 does not require classification in terms of chronic aquatic toxicity.