Abstract: Medical article of manufacture comprising compositions, comprising: at least one polyisocyanate, preferably a non-aromatic polyisocyanate, in the monomer or prepolymer state; at least one polypol; and at least one organic compound comprising one or more phosphite functional groups, in the proportion of at least 1% by weight with respect to the total weight of the polyol or polyols, this organic compound being, in addition, non-aromatic and the carrier of at least one free hydroxyl group capable of reacting with an isocyanato group; and, if appropriate, at least one catalyst of the polymerization reaction of a polyisocyanate and of a polyol.