Iron cobalt black spinel

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.6 µg/L

Extrapolation method:

sensitivity distribution

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

2.36 µg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

0.37 mg/L

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

9.5 mg/kg sediment dw

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

9.5 mg/kg sediment dw

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

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

As defined in Part B, Section 1 of the Chemical Safety Report, the substance is an inorganic compound with very low solubility. Therefore, there are no mandatory testing requirements for any of the required ecotoxicological endpoints. As a result, the determination of PNEC levels for this substance itself that are based on ecotoxicological studies cannot be conducted.

A transformation/dissolution test according to OECD 29 with the substance, however, demonstrated that small amounts of the individual inorganic building block (i.e., the element Cobalt) could be released in aqueous media. Therefore, the PNECs presented are based on Co and not on the substance itself.

It was shown in a screening test according to OECD 29 that the highest release of Co occurred at pH 6.0. Therefore, it was decided to conduct the full test at the most relevant pH with respect to ecotoxicology, i.e. at acidic pH value.  For the Co-cation, the acute ERV is 52.0 µg/L and the chronic ERV is 7.6 µg /L for acidic and alkaline pH values. The acute and chronic (ERVs) which are comparable to the most sensitive aquatic ecotoxicological endpoint were taken from the report "Cobalt REACH Consortium: Classification proposals for ‘ERV’ and ‘TDp’ substances, v4.1 – May 2017 (attached chapter 13 in IUCLID).

Conclusion on classification

The transformation and dissolution of Co-cation from the substance was evaluated according to the T/D Protocol (OECD 29) (transformation/dissolution protocol, see section 4.8).

The full test was performed at 1, 10 and 100 mg/L loadings for 7 days and at 1 mg/L loading for 28 days and at the pH of maximum release of the most metals, i.e. at pH = 6.0.

The acute and chronic Ecotoxicity Reference Values (ERVs) for Co were taken from a document prepared by Cobalt Reach Consortium (2017): The acute ERV is 52 µg Co/L and the chronic ERV is 7.6 µg Cr/L for acidic and alkaline pH values. The mean concentration of three replicates/concentrations was 4.38, 31.50 and 103.73 µg Co/L at a loading rate of 1, 10 and 100 mg/L and after 7 days. The measured Co-concentrations at a loading rate of 1 and 10 mg/L are below the acute ERV and thus, no acute classification has to be applied according to CLP.

After 28 days and a loading of 1 mg/L, the mean measured concentration was 5.07 µg Co/L. This concentration is lower than the chronic ERV and thus no chronic classification has to be applied to the substance according to CLP.

In conclusion, the results according to the T/D Protocol compared with the ERVs for the most ecotoxicological relevant metals of the substance shows that the substance has not to be classified according to CLP.