Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no hazard identified

Marine water

Hazard assessment conclusion:
no hazard identified

STP

Hazard assessment conclusion:
no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:
no hazard identified

Sediment (marine water)

Hazard assessment conclusion:
no hazard identified

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
no hazard identified

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 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 blocks of this substance (i.e., the elements Sn and Zn) could be released in aqueous media. It was shown in a screening test that the highest release of Zn occurred at pH 6, whereas for Sn the highest release was observed at pH 8.5. However, the release of Zn at pH 6 exceeded the release of Sn at pH 8.5 by a factor of ca. 10. Due to the fact that the dissolution of Zn is much higher compared to Sn under environmental relevant pH values and the eco-toxicological relevance of Zn is comparable or even higher compared to Sn, it was decided to conduct the full test at the most relevant pH with respect to ecotoxicology, i.e. at pH 6. The lower eco-toxicological relevance of Sn compared to Zn are given by the available aquatic endpoints derived from test with aquatic organisms: The lowest acute and chronic ERVs are 0.136 and 0.019 mg Zn/L (see REACH dossier of Zn oxide (CAS 1314-13-2) for details), whereas the lowest acute endpoint for Sn is 0.2 mg Sn/L (Cicads 65, 2005 for tin and inorganic tin compounds; Walsh GE, McLaughlin LL, Lores EM, Louie MK, Deans CH. 1985. Effects of organotins on growth and survival of two marine diatoms, Skeletonema costatum and Thalassiosira pseudonana. Chemosphere 14: 383-392). A reliable chronic endpoint for the most sensitive species of aquatic plants to Sn is not available.

Conclusion on classification

The transformation and dissolution of Zn and Sn from the substance was evaluated according to the T/D Protocol (OECD 29) (transformation/dissolution protocol, see section 4.8 attached). The transformation and dissolution of the further individual inorganic building blocks of this substance (i.e., the elements Ti and W) were not considered further since their ecotoxicological relevance is negligible compared to Zn and Sn. 

 

The full acute test was performed at 1, 10 and 100 mg/L loadings for 7 days and at the pH of maximum release of the most eco-toxicological relevant metal, i.e. Zn at pH 6.

The acute and chronic Ecotoxicity Reference Values (ERVs) for Zn was taken from the REACH dossier of Zn oxide (CAS 1314-13-2). The maximum Zn concentration of three replicates/concentrations was 11, 28 and 300 µg/L at a loading rate of 1, 10 and 100 mg/L. These concentrations are far below the acute ERV of 413 µg/L for pH 6-<7 and thus the compound has not to be acutely classified according to GHS.

The results of the full acute transformation/dilution test indicates that no additional Zn is released after 24 hours of incubation. Thus a chronic 28 day test at 1 mg/L loading was not conducted.

The maximum Zn concentration of 11 µg/L at a loading rate of 1 mg/L is by far below the chronic ERV of 82 µg/L for pH 6-<7 and thus no chronic classification has to be applied to the substance according to GHS.

 

For sake of completeness, the available data at alkaline pH according to T/D Protocol was taken into account as well:

The results of the 24 h screening test with a loading of 100 mg/L at pH 8.5 shows that the Zn release is much lower than at pH 6. Thus, the assessment at alkaline pH value for Zn is covered with the justification made above for pH 6. For Sn, the release is low as well not exceeding 23 µg/L at a loading rate of 100 mg/L. This dissolution/transformation concentration for Sn is also lower than the lowest acute endpoint for Sn, which is 200 µg Sn/L (Cicads 65, 2005 for tin and inorganic tin compounds; Walsh GE, McLaughlin LL, Lores EM, Louie MK, Deans CH. 1985. Effects of organotins on growth and survival of two marine diatoms, Skeletonema costatum and Thalassiosira pseudonana. Chemosphere 14: 383-392).

 

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 GHS.