Cobalt molybdate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.006 mg/L

Assessment factor:

5

Extrapolation method:

sensitivity distribution

PNEC freshwater (intermittent releases):

0.005 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.015 mg/L

Assessment factor:

5

Extrapolation method:

sensitivity distribution

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

18.57 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

9.37 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

23.51 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.074 mg/kg soil dw

Assessment factor:

50

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

The ecotoxicity databases on the effects of soluble cobalt and molybdenum compounds to aquatic, soil- and sediment-dwelling organisms are extensive. It should be noted that the environmental fate pathways and ecotoxicity effects assessment of cobalt molybdenum oxide is based on the assumption that adverse effects to aquatic, soil- and sediment-dwelling organisms are a consequence of exposure to the bioavailable cobalt ion and molybdenum ion, respectively, released by the parent substances. The result of this assumption is that the ecotoxicology will be similar for all soluble cobalt and molybdenum substances used in the ecotoxicity tests. Therefore, data from soluble cobalt and molybdenum substances are used in the derivation of chronic ecotoxicological NOEC and L(E)C10 values. If both NOEC and L(E)C10 data are available for a given species, the L(E)C10 value was used in the effects assessment.

Conclusion on classification

Classification related key information

Water solubility: 508 mg/L (OECD 105)

Biodegradation in water: not applicable (inorganic substance)

Aquatic acute toxicity:

to fish:          96 h, LC₅₀(Oncorhynchus mykiss):  5.22 mg/L

to algae:       72 h, ErC₅₀(Ditylum brightwellii):     1.11 mg/L

to crustacea: 48 h, EC₅₀(Daphnia magna):          5.53 mg/L

to aquatic plants: 96 h, EC₅₀(Spirodela polyrhiza): 0.52 mg/L

 

Aquatic chronic toxicity:

to fish:          16 d, NOEC (Brachydanio rerio):      0.22 mg/L

to algae:       72 h, NOErC (Chlorella vulgaris):      2.23 mg/L

to crustacea: 28 d, NOEC (Daphnia magna):     0.011 mg/L

 

Classification justification according to CLP

Based on the data above, there is no evidence of rapid environmental transformation of cobalt molybdenum oxide. The acute aquatic toxicity L(E)C50 values are > 1 mg/L for fish, algae and aquatic invertebrates. However, for aquatic plants there is an EC50 of 0.52 mg/L available which was chosen as acute Environmental Reference Value. Valid chronic toxicity data are available - the lowest NOEC is 0.011 mg/L for Daphnia and was chosen as chronic Environmental Reference Value.

Therefore, cobalt molybdenum oxide needs to be classified and labelled as environmental hazard Acute Cat. 1 and Chronic Cat. 1 according to the Regulation (EC) No.1272/2008 (CLP) and the Regulation (EU) No. 286/2011 (2^ndATP).

 

M-factor for acute aquatic toxicity:      1
M-factor for chronic aquatic toxicity:   1

 

Classification justification according to DSD

Based on the data above, there is no evidence of rapid environmental transformation of cobalt molybdenum oxide. However, for aquatic plants there is an EC50 of 0.52 mg/L available which was chosen as acute Environmental Reference Value. Valid chronic toxicity data are available - the lowest NOEC is 0.011 mg/L for Daphnia and was chosen as chronic Environmental Reference Value.

Therefore, cobalt molybdenum oxide needs to be classified and labelled as environmental hazard R50/53 according to Directive 67/548/EEC.