Polyolefin mouldings that have excellent stability on permanent contact with chlorinated water comprise, as stabilizer, at least a compound selected from the group consisting of i) an epoxidized fatty acid having 3 to 22 carbon atoms or an aklyl ester thereof having 1 to 18 carbon atoms; and/or ii) an organotin compound; and/or iii) a compound containing at least one radical of the formula A or B.