Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

In order to be consistent with the EU Risk Assessment Report, the Koc of 4.47 has been selected.

The Henry’s Law Constant was empirically determined at 37.1 Pa·m3/mol.

Additional information

The Henry’s Law Constant was empirically determined at 37.1 Pa·m3/mol by Artola (2002). The other empirical information illustrates that volatilisation of AHTN may play a role. To be consistent with the EU Risk Assessment Report, this value is used for further calculations.

The water solubility of AHTN is low. In combination with the high log Kow, AHTN is expected to readily sorb to organic materials and lipids.

Due to the high variability in Koc, no single value for Koc could be identified. Consequently, the value estimated by the EUSES model based on log Kow was selected. The EPI suite calculations based on the Molecular Connectivity Index produced a Koc which was very large when compared to measured adsorption coefficients. The Koc calculated on the basis of Log Kow were more in line with the experimental results. The EU Risk Assessment used the formula Log Koc = 0.81·log Kow + 0.1 (for predominantly hydrophobics) and a log Kow of 5.4 to obtain a log Koc of 4.5. Note that the log Kow of 5.7 (Rudio 1993) results in a log Koc of 4.7. In the v2.00 version of KocWin, the new equation for the Koc calculation gives log Koc 4.9. The differences in the calculations are marginal, when considering the background of the wide distribution of Koc values measured in the environment. In order to be consistent with the EU Risk Assessment Report, the Koc of 4.47 has been selected.