Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.62 µg/L
Assessment factor:
3
Extrapolation method:
sensitivity distribution

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
2.36 µg/L
Assessment factor:
3
Extrapolation method:
sensitivity distribution

STP

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

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
53.8 mg/kg sediment dw
Assessment factor:
10
Extrapolation method:
assessment factor

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
69.8 mg/kg sediment dw
Assessment factor:
10
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:
10.9 mg/kg soil dw
Assessment factor:
2
Extrapolation method:
sensitivity distribution

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Conclusion on classification

 Water solubility is 135.6 g Co/L at 20C

 Expected to be readily soluble under TDp as well

 Molecular weight is 182.95 g/mol

 The acute and chronic ERVs for the cobalt ion are 90.1 μg/L and 4.9 μg/L respectively, and are corrected for molecular weight (MW) to substance-specific ERVs using the following equation:

ERVsubstance=ERVCo×MWsubstance/ (n×MWCo)

where n is the stoichiometric number of Co atoms in the substance molecule. Substance-specific ERVs are:

 Acute ERV: 279.7 μg/L– <1mg/L so Acute 1

 The EU CLP guidance document (ECHA, 2011) permits consideration of the “rapid removal” and sequestration of metals in the environment much the same way as the concept of “rapid degradation” is considered for organic chemicals. To indicate “rapid removal’ for a metal, it is assumed that one must demonstrate greater than 70% removal of soluble metal within 28 days of addition to the water column, as is the case with organic compounds. Furthermore, one must demonstrate that the potential for metal remobilisation from sediments is limited, for example by changes in metal speciation, remineralisation and permanent burial in the sediment. If these conditions are met, the metal is considered “rapidly removable” and poses little environmental risk. Results of modelling using the UWM indicate that the cobalt ion satisfies the requirements for “rapid” metals removal, i.e. > 70% removal from the water column in 28 days, and the demonstration of limited sediment remobilisation potential under most environmental conditions. Based on this evaluation the Chronic ERV: 15.2 μg/L– between 10 and 100μg/L so Chronic 2

·     Proposed self-classification:

 Acute 1 (M = 1) and Chronic 2