Olivine, cobalt silicate blue

Ecotoxicological Summary

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

Olivine, cobalt silicate blue is moderately soluble in environmental media. Based on results of a standard transformation/dissolution test according to OECD Series No 29, the dissolution at a loading of 1 mg/L Olivine, cobalt silicate blue results at pH 6, the pH that maximises dissolution, in dissolved cobalt levels of 139 µg Co/L and 185 µg Co/L after 7 and 28 days, respectively. Thus, the rate and extent to which Olivine, cobalt silicate blue produces soluble (bio)available ionic and other cobalt-bearing species in environmental media is limited. Olivine, cobalt silicate blue contains also silicon, but silicon does not have an ecotoxic potential (see OECD SIDS Silicon dioxide, 2004), as also confirmed by the absence of respective ecotoxicity reference values in the Metals classification tool (MeClas) database (http://www.meclas.eu/ accessed on 18.04.2021).

Further, the limited solubility of Olivine, cobalt silicate blue is expected to determine its behaviour and fate in the environment, and subsequently its bioavailability and potential for bioaccumulation and ecotoxicity. A conservative read-across approach is applied based on all information available for different inorganic cobalt substances and the fate of the released cobalt ions can ultimately be expected to be similar to the common fate of cobalt ions in the environment. For further information on the applied read-across approach, please refer to the RAAF document “Read-across approach for environmental toxicity of the pigments “Reaction mass of cobalt olivine and crystalline silicon dioxide” & “Olivine, cobalt silicate blue", 2021 attached in IUCLID Section 13.

The PNEC and ERV derivations for cobalt ions are explained in section "7.6. PNEC derivation and other hazard conclusions" ofthe respective CSR ofsubstances in the “Cobalt Category”, including cobalt dichloride (EC # 231-589-4, CAS # 7646-79-9).

Conclusion on classification

Olivine, cobalt silicate blue contains cobalt and silicon, but silicon does not have an ecotoxic potential (see OECD SIDS Silicon dioxide, 2004), as also confirmed by the absence of respective ecotoxicity reference values in the Metals classification tool (MeClas) database (http://www.meclas.eu/ accessed on 18.04.2021). Thus, the aquatic hazard potential of the substance Olivine, cobalt silicate blue is evaluated by comparing the dissolved cobalt levels resulting from the transformation/dissolution test after 7 and 28 days at a loading rate of 1 mg/L at pH 6, the pH that maximises dissolution, with the lowest acute and chronic ecotoxicity reference values (ERVs), respectively, as determined for the (soluble) cobalt ion. The reported ERVs for cobalt ions are as follows:

Acute:             Lemna minor:              52.0 μg/L

Chronic:          Hyalella azteca:           7.6 μg/L

The dissolution of Olivine, cobalt silicate blue results in dissolved cobalt levels of 139 µg Co/L and 185 µg Co/L after 7 and 28 days, respectively (Kopf, 2014).

Regarding the potential for short-term toxicity, the dissolved cobalt concentration of 139 µg Co/L in the T/D test after 7 days at pH 6 is higher than the acute ERV for Lemna minor of 52.0 μg Co/L. Hence, the substance Olivine, cobalt silicate blue may be considered sufficiently soluble to cause short-term toxicity at the level of the acute ERV for cobalt ions.

Based on the maximum cobalt content of 55.9 % for Olivine, cobalt silicate blue, the acute ERV of cobalt ions can be recalculated for Olivine, cobalt silicate blue resulting in an ERV of 93.0 μg/L. In accordance with Table 4.1.0 (a) of Regulation (EC) No 1272/2008, the substance Olivine, cobalt silicate blue would meet classification criteria for acute (short-term) aquatic hazard Category 1.

For a more accurate refinement, the dissolution rate of Olivine, cobalt silicate blue is taken into account, and the ERV for Olivine, cobalt silicate blue is calculated from the acute ERV of cobalt and the transformation/dissolution data of Olivine, cobalt silicate blue obtained under the same circumstances as follows:

ERV(Pigment) = ERV(Co++) x loading(Pigment) in TD test / dissolved concentration (Co+) measured after 7 days in TD test, resulting in an ERV of 374.1 μg/L. In accordance with Table 4.1.0 (a) of Regulation (EC) No 1272/2008, the substance Olivine, cobalt silicate blue would also meet classification criteria for acute (short-term) aquatic hazard Category 1. Further, an M-factor of 1 applies in accordance with Table 4.1.3 of Regulation (EC) No 1272/2008.

Thus, in accordance with Table 4.1.0 (a) and Table 4.1.3 of Regulation (EC) No 1272/2008 and Figure IV.1 Classification strategy for determining acute aquatic hazard for metals of ECHA’s Guidance on the Application of the CLP Criteria (V 5.0, July 2017), the substance Olivine, cobalt silicate blue meets classification criteria for acute (short-term) aquatic hazard Category 1 (acute M-factor 1).

Regarding the potential for long-term toxicity, the dissolved cobalt concentration of 185 µg Co/L in the T/D test after 28 days at pH 6 is higher than the long-term ERV of cobalt ions of 7.6 μg/L for aquatic invertebrates (Hyalella azteca). Hence, the substance Olivine, cobalt silicate blue may be considered sufficiently soluble to cause long-term toxicity at the level of the chronic ERV for cobalt ions. The cobalt ion satisfies the requirements for “rapid environmental transformation, i.e. > 70% removal from the water column in 28 days and limited sediment remobilisation potential under most environmental conditions.

Based on the maximum cobalt content of 55.9 % for Olivine, cobalt silicate blue, the chronic ERV of cobalt ions can be recalculated for Olivine, cobalt silicate blue resulting in an ERV of 13.6 μg/L. In accordance with Table 4.1.0 (b) (ii) of Regulation (EC) No 1272/2008, the substance Olivine, cobalt silicate blue would meet classification criteria for long-term aquatic hazard Category 2.

For a more accurate refinement, the dissolution rate of Olivine, cobalt silicate blue is taken into account, and the ERV for Olivine, cobalt silicate blue is calculated from the chronic ERV of cobalt and the transformation/dissolution data of Olivine, cobalt silicate blue obtained under the same circumstances as follows:

ERV(Pigment) = ERV(Co++) x loading(Pigment) in TD test / dissolved concentration (Co+) measured after 28 days in TD test, resulting in an ERV of 41.08 μg/L.In accordance with Table 4.1.0 (b) (ii) of Regulation (EC) No 1272/2008, the substance Olivine, cobalt silicate blue would also meet classification criteria for long-term aquatic hazard Category 2.

Hence, the substance Olivine, cobalt silicate blue is considered sufficiently soluble to cause long-term toxicity at the level of the chronic ERV for cobalt ions and in accordance with Table 4.1.0 (b) (ii) of Regulation (EC) No 1272/2008 meets classification criteria for long-term aquatic hazard Category 2.

 

In sum, the substance Olivine, cobalt silicate blue is of limited solubility and meets classification criteria of Regulation (EC) No 1272/2008 for acute (short-term) aquatic hazard Category 1 (acute M-factor of 1) and chronic (long-term) aquatic hazard Category 2.These hazard conclusions are in agreement with classification conclusions of the Metals classification tool (MeClas) database (http://www.meclas.eu/ accessed on 18.04.2021).