Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

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 environmentally relevant pH range according to Franco and Trapp (2008, 2009, 2010). This resulted in a log Koc of 4.25 at pH 5 to 8 (Koc = 17958 at pH 5 to Koc = 17781 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 80.5 %, 19.1 %, 0.3 % 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.