Niax® catalyst esn appears as a liquid mixture consisting of 95% dimethylaminopropionitrile by mass (C5H10O2, CAS: 1738-25-6) and 5% bis(2-[dimethylamino)ethyl] ether (C8H20N2O, CAS: 3033-62-3). Used as a catalyst in the manufacture of flexible polyurethane foams. Sale of the material was discontinuted in1978 after its use was linked to urological disorders among workers at a number of factories manufacturing these foams.