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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 to cause toxic effects if accumulated (in higher organisms) via the food chain

Additional information

Latest scientific discussions state, that derivation of PNECs for the aquatic compartment is not suitable for iron oxides due to the following reasons:

a) It is not required to calculate the PNEC, because: •due to the overall natural occurrence of iron oxides in the environment, the PECregional is of high value and of high variation among country-specific characteristics (ARCHE, 2010b). A distinction between the natural (background) and anthropogenic fractions is not possible. •Available data do suggest that iron salts are relatively non toxic and this was sufficient for the EU Classification and Labelling Committee to determine that there was no need for classification of iron salts (European Commission 2005). As a consequence of this it is also concluded that there is no need to perform additional aquatic hazard tests for highly insoluble massive and sparingly soluble forms of iron (like iron oxides) for REACH as these substances are non-hazardous. These forms of iron have solubility’s in the low µg/L range and ferrous and ferric ions are rapidly removed from water column in natural ecosystems through the formation of insoluble iron hydroxides. Literature studies have extensively used test solutions with iron concentrations above the respective solubility limit. Due to physical effects of precipitated material, some of these studies are meaningless for the investigation of intrinsic toxicity. Iron ions released to surface waters quickly form insoluble iron hydroxides in mixing zones. These positively charged iron (III) colloids will react with the negatively charged mucus that lines the fish gill. This accumulation of iron on the fish gill results in physical effects. Iron has a complex redox chemistry. In very special conditions, transient iron species that cause toxicity can be formed. These conditions however are not typical of most ambient conditions and are more representative of specific mixing zones. In ambient conditions, the dissolved natural background concentrations of iron are, in most cases, in equilibrium; therefore addition of iron would lead to the precipitation of iron compounds from solution. Intrinsic toxicity would therefore not be observed (the Iron Platform 2010).

b) A PNEC cannot technically be calculated: •owing to the complex redox chemistry of iron. Ongoing investigations were performed to investigate whether intrinsic iron toxicity (e.g. disruption of ionic transport systems and oxidative stress) at low pH and high dissolved organic carbon concentration exists. In very special conditions of low pH water with elevated iron entering neutral or alkaline water, transient iron species can be formed that cause toxicity. These conditions, however, are not typical of most ambient conditions and are more representative of specific mixing zones. In ambient conditions, the dissolved natural background concentrations of iron are, in most cases, in equilibrium; therefore addition of iron would lead to the precipitation of iron compounds from solution. Intrinsic toxicity would therefore not be observed. (the Iron Platform, 2010).

Concerning the terrestrial compartment, latest scientific discussions state, that a PNEC derivation for Iron is not suitable. Iron is amongst the most common elements in the earth’s crust and can be found in great abundance in the terrestrial environment. The overall natural occurrence of iron oxides in soil, the PECregional is of high value and of high variation among country-specific characteristics (ARCHE, 2010c). It is therefore unlikely that exposure to iron salts arising from applications covered by this assessment under oxygenated and physiologically tolerable pH conditions will result in toxic concentrations of iron in the soil compartment (the Iron Platform, 2010). As discussed for the aquatic compartment, a quantitative risk characterisation by comparing the PEC with the PNEC is not suitable, as concentrations resulting from iron oxides are low compared to those from background concentrations. A refinement of the risk characterisation is also not possible due to the differences in regional background concentrations. The relative contributions of anthropogenic iron to the existing natural pools of iron in soils is therefore not relevant either in terms of added amounts and in terms of toxicity. Based on these exposure considerations additional soil testing is not warranted. Derivation of a PNECsoil is therefore not performed.

Conclusion on classification

Based on the available data and following the discussions no hazard was identified for each member of the “Iron oxides category”. The statements of each cited papers leads to the conclusion that no classification according to both Directive 67/548/EEC and GHS (Regulation EC 1272/2008) is required.

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