ISO 305:1990

Plastics — Determination of thermal stability of poly(vinyl chloride), related chlorine-containing homopolymers and copolymers and their compounds — Discoloration method

Specification of a comparing method, based on the increasing discoloration of polyvinylchloride when exposed to heat, due to a decomposition reaction. Test pieces in diskform are placed between aluminium pieces and heated to the specified test temperature. After specified periods one test specimen at a time is taken out and the degree of discoloration assessed by visual examination or by measuring with a photometer.