Abstract: The instant invention is directed to a process for the production of microcellular elastomeric moldings comprising:(A) introducing a reaction mixture into a closed mold, said reaction mixture comprising:(i) an organic polyisocyanate,(ii) a hydroxyl group containing compound having a molecular weight of from 1800 to 12,000,(iii) a catalyst for the reaction between hydroxyl groups and isocyanate groups,(iv) an active aromatic diamine having at least one alkyl substituent in the orthoposition to a first amino group and two alkyl substituents in ortho-position to a second group, and(v) air and/or nitrogen dissolved under pressure in any one or more of Components (i), (ii), (iii) or (iv),(B) allowing said reaction mixture to react in said mold and(C) removing the resultant product from said mold, the improvement wherein in any of Components (i), (ii), (iii) or (iv) which does contain said air and/or nitrogen dissolved therein there is included an inorganic, finely divided, nitrogen adsorbing agent in an amount suf