Slags, ilmenite electrothermal smelting

Toxicity to birds

Description of key information

Waiving arguments for omitting the long-term test with birds is mainly based on the fact that there is at present little or no evidence to support that food chain transfer of Ti and Fe, the main constituents of UGI products, has ever caused secondary poisoning.

Additional information

Waiving arguments for omitting the long-term test with birds is mainly based on the fact that there is at present little or no evidence to support that food chain transfer of Ti and Fe, the main constituents of UGI products, has ever caused secondary poisoning. Secondary poisoning is concerned with toxic effects in the higher members of the food chain, either living in the aquatic or terrestrial environment, which results from ingestion of organisms from lower trophic levels that contain accumulated substances.

According to the REACH Guidance documents, there is no need for a detailed assessment of secondary poisoning if i) there are no indications for bioaccumulation and ii) there is no potential for toxic effects if accumulated in higher organisms (based on classification on the basis of mammalian toxicity data).

Therefore an assessment of the potential of both materials for secondary poisoning is not deemed necessary due to the following arguments: BCF's of Ti are very low and therefore a significant transfer in the food chain is not expected. Indeed, data on the bioaccumulation of Ti clearly show that a significant bioaccumulation in fish and plants is not likely to occur. Federici et al. (2007) performed accumulation experiments with rainbow trout (Oncorhynchus mykiss) in tap water using powder form of TiO2 nanoparticles. After 7 to 14 days of exposure the authors noticed very similar concentrations of Ti in different fish tissues (gills, liver, muscle, brain), i.e. between 11.5 and 21.1 mg Ti/kg dw, irrespective of the added Ti concentrations in the aqueous test medium. Poor adsorption into internal organs and therefore no bioaccumulation of Ti was concluded. Bioaccumulation data of Ti in plants have been generated by Caille et al. (2005). After 54 days of exposure of different plant species (rape, Brassica napus; cabbage, Brassica oleracea; red fescue, Festuca rubra) the authors noticed very similar low concentrations of Ti in the leaves, i.e. between 0.7 and 2.4 mg Ti/kg dw, resulting in very low biota-to-soil-accumulation factors (BSAF) between 0.0002 and 0.0008 kg/kg.

Oral toxicity data of Ti towards mammalian/birds could not be retrieved from literature and no particularly sensitive higher organism has been identified.

Iron is amongst the most common elements in the earth's crust and can be found in great abundance in both the terrestrial as sediment environment. The relative contributions of anthropogenic iron to the existing natural pools of iron in soils and sediments is therefore not relevant either in terms of added amounts and in terms of toxicity. Based on these exposure considerations additional sediment and/or soil testing is not warranted (reference: Iron REACH dossier, CAS: 7439-89-6)

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Avian toxicity data are used in the assessment of secondary poisoning risks for the aquatic and terrestrial food chains. Iron is an essential trace element, well regulated in all living organisms. The available evidence shows the absence of iron biomagnification across the trophic chain both in the aquatic and terrestrial food chains. The existing information suggests not only that iron does not biomagnify, but rather that it tends to exhibit biodilution. Therefore, the need for additional testing for secondary poisoning can be waived.