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The Henry's Law Constant for PACM (4,4'-methylenebis(cyclohexylamine)) was estimated by the bond estimation method of the HENRYWIN Program (v3.20) of EPI Suite v4.10 to be 4.6E-04 Pa m³/mol at 25 °C, which is equal to 4.54E-09 atm m³/mol. A value calculated by the ratio of vapour pressure to water solubility results in a supporting value (9.39E-04 Pa m³/mol at 20 °C) that is within a factor of two of the key value, a low level of variability for this parameter. At environmental conditions (pH 5 to 9) the molecule is expected to be ionised, therefore a pH-corrected HLC was calculated according to the REACH Guidance document (2008). The resulting Henry's Law Constant was 3.65E-8 Pa m³/mol at pH 7 (range pH 5 to 9: 3.65E-10 to 3.63E-06 Pa m³/mol; BASF, 2012). Based on the Henry's Law Constant for the charged molecule, the substance will not evaporate from the water surface into the atmosphere.

The Koc value for PACM was estimated by the Molecular Connectivity Index (MCI) module and the log KOW module. The MCI method is the more reliable of the two calculation methods in the KOCWIN v2.00 model. The MCI method resulted in a Koc of 446 (log Koc = 2.65), while the log KOW method gave a slightly lower Koc of 103 (log Koc = 2.01). Both calculated values refer to the uncharged molecule. However at environmentally relevant conditions (pH 5 to 8), PACM will be present in ionised form (pKa2 = 11.1 at 20 °C; Baltussen, 2010). Therefore, the Koc was also calculated for the environmetally relevant pH range according to Franco and Trapp (2008, 2009, 2010). This resulted in a log Koc of 4.23 at pH 5 to 8 (Koc = 17047 at pH 5 to Koc = 17034 at pH 8).

According to a Mackay Level I (static equilibrium) fugacity calculation, the main target compartments will be the hydrosphere (98.3 %), followed by sediment and soil (0.85 % each) and air (0.032 %). Assuming equal emissions to the air, water and soil compartments, a Mackay Level III (dynamic steady-state) fugacity calculation predicted a distribution of 75.1 %, 24.8 %, 0.09 % and 0.06 % to the soil, water, sediment and air compartments, respectively. The distribution model applies to the uncharged molecule and does not take into consideration that PACM will be ionised at environmentally relevant pH.