Redistd in an Ar or N₂ atmosphere in a fume hood, and stored over KOH in sealed bottles in a refrigerator. Commercial imine (CAS NO. ) has been dried over sodium and distd from the metal through an efficient column before use. It is a weaker base than Me₂NH (pK 10.87) but is caustic to the skin. It should not be inhaled, causes inflammation of the eyes, nose and throat and one may become sensitised. It is sol in H₂O and has an ammoniacal smell and reacts with CO₂. Pure Ethyleneimine is comparatively stable but polymerises in the presence of traces of H₂O and is occasionally explosive in the presence of acids. CO₂ is sufficiently acidic to cause polymerisation (forms linear polymers) which is not free radical promoted. It is stable in the presence of bases.

The violet 2:1 Cu complex crystd from EtOH containing a few drops of Ethyleneimine and adding Et₂O has m 142 °C(decomp). The picrate has m 142 °C. It has also been dried with BaO, and distd from sodium under nitrogen.