Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0 mg/L
Assessment factor:
50
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.001 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0 mg/L
Assessment factor:
500
Extrapolation method:
assessment factor
PNEC marine water (intermittent releases):
0.001 mg/L

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
100 mg/L
Assessment factor:
10
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
0.037 mg/kg sediment dw
Assessment factor:
500
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.004 mg/kg sediment dw
Assessment factor:
5 000
Extrapolation method:
equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
0.028 mg/kg soil dw
Assessment factor:
500
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Aquatic

A standard acute toxicity study with Daphnia was conducted as a limit test at 100% v/v saturated solution (equivalent to 0.0735 mg/L) and showed no effects. Therefore the 48 Hour EC50 was greater than 0.074 mg/L, and the NOEC was 0.074 mg/L. A standard acute toxicity study with fish was conducted with MnO2 as a limit test at 100% v/v saturated solution and showed no effects. Therefore the 96 Hour LC50 was greater than 100 %v/v and the NOEC was 100 %v/v (equivalent to 0.074 mg/L). Similar results were obtained in a standard chronic limit test study on algae, resulting in 72h EC50 > 100% v/v saturated solution, and NOEC = 100% v/v saturated solution. An 8 day chronic study on Daphnia gave NOEC = 10% v/v saturated solution (equivalent to 0.074 mg/L).

Sediment

No experimental data on sediment toxicity exist. The data are not considered to be required as the hazard assessment performed during the chemical safety assessment concludes that the substance is not classified and the risk assessment concludes that the substance is of no immediate concern to the environment.PNEC sediment is calculated by the equilibrium partitioning method.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 MnO2. 

Terrestrial

No experimental data on terrestrial toxicity exist. The data are not considered to be 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.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 MnO2

STP

No effects on sewage sludge were observed in a standard 3hr study on MnO2. Hence the NOEC for MnO2 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 metalcompound under investigation (as determined during transformation/dissolution protocol testing).

The relevant ecotoxicological values (environmental reference values, ERV) for manganese were established by considering thedatabase 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 Manganese dioxide (Rodriguez, 2010). During the transformation/dissolution protocol test with Manganese dioxide 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 4.6, 10.5 and 47.1 µg Mn/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 15.9 µg Mn /L.

Since the level of Mn release following a 7 day exposure of Manganese dioxide to environmentally relevant water, at all three loading rates, was lower than the acute ERV, Manganese dioxide does not require classification in terms of acute aquatic toxicity. Since the level of Mn release following a 28 day exposure of Manganese dioxide to environmentally relevant water, at a loading rate of 1 mg/L, was lower than the chronic ERV, Manganese dioxide does not require classification in terms of chronic aquatic toxicity.