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Environmental fate & pathways

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A relevant adsorption of trisodium nitrilotriacetate (Na3NTA) onto the oragnic fraction of soils, sediments or suspended solids is not expected due to the ionic structure of the substance and a log Kow of -13.2 (pH 7). However, interaction with the mineral phase may be possible.

This assumption is supported by the studies conducted by Dunlap et al. (1971) and Bolton et al. (1993) who could demonstrate that Na3NTA is neither strongly sorbed by loam, clay-loam and sand soils or marine surface sediments (Kp sediment-water = 1.6 l/kg).

Therefore, in accordance with the EU RAR (2005) on trisodium nitrilotriacetate, in exposure calculations a distribution coefficient Kp of 1.6 l/kg is to be used for adsorption onto sediments, suspended particles and soils.