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Environmental fate & pathways

Adsorption / desorption

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Description of key information

log Koc between 1.88 and 3.19 (experimental data)

Key value for chemical safety assessment

Koc at 20 °C:
75

Additional information

Since no reliable adsorption tests are available for C8-14AS NH4 & TEA (CAS 96690-74-3), in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read-across to other structurally related category members was conducted.

In the publication of Marchesi et al. (1991), sediment sorption data for several alkyl sulfates with different carbon chain lengths are presented. A clear trend can be seen - adsorption coefficient increases with the increasing length of the carbon chain. The determined Koc values are:

- for C8 homologue (CAS 142-31-4) between 75 -100 which corresponds to log Koc values in the range of 1.88 and 2.0.

- for C10 homologue (CAS 142-87-0) between 122 and 178 which corresponds to log Koc values in the range of 2.09 and 2.25.

- for C12 homologue (CAS 151-21-3) between 316 and 446 which corresponds to log Koc values in the range of 2.5 and 2.65.

- for C14 homologue (CAS 1191-50-0) between 1337 and 1567 which corresponds to log Koc values in the range of 3.13 and 3.19.

Due to structural and property similarities with the tested category members these results apply also to C8-14AS NH4 & TEA (CAS 96690-74-3). The Koc range is between 75 and 1567 corresponding to the log Koc range between 1.88 and 3.19. Adsorption of the substance to soil or sediment is therefore low to moderate. For the PNEC sediment and soil derivation according to the equilibrium partitioning method (EPM), the lower boundary of the range (Koc = 75) was taken into account, since this value represents the worst case scenario for the chemical safety assessment.

[LogKoc: 1.88]