Abstract: A polypropylene composition comprising components A), B) and C), wherein component A) is a hindered amine light stabilizer selected from the group consisting of the compounds of formulae (A-I-1), (A-I-2), (A-I-3), (A-III-1) and (A-IV-1) as defined for the present invention, component B) is a natural or synthetic hydrotalcite, component C) is a phenolic antioxidant selected from the group consisting of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, ethylene bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyrate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate and 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin, and wherein the weight ratio of component A) to component B) is 1:10 to 10:1.

Abstract: An article in the form of a pipe, cable or geomembrane comprising polyethylene or polypropylene, and components A) and B), wherein component A) is a hindered amine light stabilizer containing a triazine residue, component B) is magnesium hydroxide which is present in an amount of 0.01% to 5% by weight relative to the weight of the polyethylene or polypropylene, and the weight ratio of component A) to component B) is 1:50 to 50:1, with the proviso that component B) is not a hydrotalcite.

Abstract: A polyethylene pipe comprising components A) and B), wherein component A) is a hindered amine light stabilizer containing a triazine residue, component B) is a natural or synthetic hydrotalcite and the weight ratio of component A) to component B) is 1:10 to 10:1.