Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Henry's Law Constant

Cyclohexylamine is characterized by a measured Henry's Law Constant of 0.42 Pa*m³/mol at a temperature of 25 °C (Altschuh, 1999).

Based on a dissociation constant of 10.68 (Perrin, 1965), the substance will, under environmental relevant conditions (pH 4 to 9), be present solely in the protonated form. Therefore, the measured HLC reflects the properties of the protonated form rather than the neutral species. According to Thomas, cited in the "Handbook of Chemical property Estimation Methods" (Lyman, 1980), cyclohexylamine volatilizes only slowly from water, whereas the rate is strongly controlled by the slow diffusion through air.

Distribution modelling

Under environmental relevant conditions (pH 4 to 9), cyclohexylamine will completely be protonated. Based on Model calculations according to Mackay Level I, the target environmental compartment for the protonated form of cyclohexylamine is water (Bayer Industry Services, 2006).