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

The lowest available acute reference values are:

Algae, Pseudokirchneriella subcapitata (following OECD Method 201)

EC50: 0.551 mg/L (0.121 mg Co/L)

Invertebrate, Daphnia magna (following OECD Method 202)

EC50: 9.2 mg/L (2.6 mg Co/L)

No compound specific acute data are available for fish species (but are typically least

sensitive trophic group)

Data classify substance as Acute 1; M = 1

Available chronic EC10 value for algae is:

Algae, Pseudokirchneriella subcapitata (following OECD Method 201)

EC10: 0.182 mg/L (0.040 mg Co/L)

Invertebrate,Ceriodaphnia dubia (following USEPA 2002)

EC10: 0.068 mg/L (0.015 mg Co/L)

No compound specific chronic data are available for fish species

Chronic data for invertebrates classify substance as Chronic 1 (M = 1) or 2 depending on

Unit World Model (UWM). 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. 

Chronic tests take precedence over acute data for chronic classification, so acute algae and invertebrate values not considered under surrogate scheme

There is no evidence for bioaccumulation or biomagnification in the environment

Proposed self-classification:

Acute 1 (M = 1) and Chronic 2 if UWM is used