Abstract: The present invention pertains to the use of at least one Brønsted superacid or metal salt of said Brønsted superacid with a ?Gacid value of 316 kcal/mol or less, as a heat and/or colour stabiliser for polyvinyl halide resin compositions. The superacid is not a perchlorate or a trifluoromethane sulphonate. The metal in the metal salt of the Brønsted superacid is preferably selected from the group consisting of alkali metals, alkali earth metals, transition metals, lanthanide metals, actinide metals, Al, Ga, In, TI, Ge, Sn, Pb, and Sb.

Abstract: The invention relates to a stabilizer system and the use thereof in the processing of vinyl chloride (co)polymers, said stabilizer system comprising at least the salt of specific hydroxyacid and one or more color stabilizers. Stabilized PVC, obtainable by compounding said stabilizer system into said vinyl chloride (co)polymer, shows good color and heat stability, while preferred stabilizer systems also are allowed to be used in food-grade, including drinking water-grade, PVC applications.