NOVELTY - Composition comprises (a) an organic material susceptible to oxidative, thermal or light-induced degradation, and (b) a 4,5-diphenyl-5H-furan-2-one compound (I).    USE - (I) is useful for stabilizing and protection of an organic material susceptible to oxidative, thermal or light-induced degradation against degradation by oxidation, heat or light (all claimed). The composition is useful for the preparation of various shaped articles e.g. floating devices, pontoons, buoys, boats, oars, automotive applications (e.g. bumpers, dashboards, battery, trunk linings and headlamp glass), road traffic devices, warning triangles, medical cases, helmets, tires, devices for space applications (rockets and satellites, e.g. reentry shields), devices for architecture and design, mining applications, street refuges, and shelters, appliances, cases and coverings in electric/electronic devices (e.g. personal computer, telephone, portable phone, printer and TV sets), flower pots, panel devices, chips, check cards, credit cards, washing machines, tumblers, ovens, wires, cables, foils for condensers, refrigerators, heating devices and air conditioners, cogwheel (gear), slide fittings, spacers, screws, bolts, handles, knobs, rotor blades, ventilators, windmill vanes, solar devices, swimming pools, swimming pool covers, pool liners, closets, wardrobes, shower cubicles, lavatory seats, diapers, shower curtains, brushes, mats, tubs, mobile toilets, tooth brushes, pipes for wire and cable protection, pipes for gas, oil and sewage, guttering, down pipes, and drainage systems, photographic paper, silos, wood substitute, plastic lumber, wood composites, tiles, tarpaulins, trays, astroturf, carpets, hygienic articles, filters, nets, ropes, cables, strings, cords, threads, safety seat-belts, clothes, underwear, gloves, boots, food packing and wrappings, bottles, cans, cartridges, syringes, medical applications, foams, dish clothes, mats, garden chairs, stadium seats, tables, couches, toys, building kits, kitchen wares, boxes for cassettes and video tapes, ball-point pens, stamps and ink-pads, mouse, shelves and tracks.    DETAILED DESCRIPTION - Composition comprises (a) an organic material susceptible to oxidative, thermal or light-induced degradation, and (b) a 4,5-diphenyl-5H-furan-2-one compound of formula (I).    A = (i) -C(=O)-OR1a, -C(=O)-N(R2a)(R3a), -CN, phenyl (optionally substituted by one or more 1-8C alkyl, 1-4C alkoxy, 5-7C cycloalkyl or halo), -H or -SO2-phenyl (when n is 1), (ii) C(=O)-O-Z1-O-C(=O)-, -C(=O)-N(R1b)-Z2-N(R2b)-C(=O)- or piperazine-N,N'-biscarbonyl (when n is 2), (iii) 3-12C alkane-tri-(oxycarbonyl), 3-ethyl-3-azapentane-1,5,2'-tri-(oxycarbonyl), 1,4,7-triazaheptane-1,4,7-tricarbonyl, 1,4,8-triazaoctane-1,4,8-tricarbonyl or 1,5,9-triazanonane-1,5,9-tricarbonyl (when n is 3), or (iv) 4-16C alkane-tetra-(oxycarbonyl), 1,4,7,10-tetraazadecane-1,4,7,10-tetracarbonyl, 1,4,8,11-tetraazaundecane-1,4,8,11-tetracarbonyl or 1,5,8,12-tetraazadodecane-1,5,8,12-tetracarbonyl (when n is 4);    n = 1-4;    R1-R10 = H, 1-8C alkyl, 4-8C cycloalkyl, phenyl, 1-4C alkoxy or halo;    R1a = H, 1-22 alkyl, 2-18C alkenyl, 3-12C alkynyl, 4-8C cycloalkyl (optionally substituted by 1 or 3 1-4C alkyl), 4-8C cycloalkyl-1-4C alkyl, bicyclic or tricyclic 5-20C alkyl, 6-14C aryl-1-4C alkyl, 2-12C alkyl (substituted by one or more hydroxyl groups), 4-18C alkyl (interrupted by one or more oxygen atoms), 2,2,6,6-tetramethylpiperidine-4-yl, 1-(1-8C alkyl)-2,2,6,6-tetramethylpiperidine-4-yl or 1-(1-4C alkoxy)-2,2,6,6-tetramethylpiperidine-4-yl;    R2a, R3a = H, 1-22C alkyl, 2-18C alkenyl, 4-8C cycloalkyl (optionally substituted by 1-3 groups comprising 1-4C alkyl), 6-10C aryl, 4-8C cycloalkyl-1-4C alkyl, 6-14C aryl-1-4C alkyl, 2-8C alkyl (substituted by one hydroxyl group), 2,2,6,6-tetramethylpiperidine-4-yl, 1-(1-8C alkyl)-2,2,6,6-tetramethylpiperidine-4-yl or 1-(1-8C alkoxy)-2,2,6,6-tetramethylpiperidine-4-yl; or    NR2aR3a = 5-7 membered saturated heterocycle;    R1b, R2b = H, 1-22C alkyl, 2-18C alkenyl, 4-8C cycloalkyl (optionally substituted by 1-3 1-4C alkyl), 4-8C cycloalkyl-1-4C alkyl, or 6-14C aryl-1-4C alkyl;    Z1 = 2-12C alkylene, 4-8C cycloalkylene, 4-8C cycloalkane-bis-(1-4C alkylene), 6-14C arene-bis-(1-4C alkylene), 3-6C alkylene (substituted by one or more hydroxyl groups), 4-12C alkylene (interrupted by one or more oxygen atoms), hexahydro-furo(3,2-b)furane-3,6-diyl, 4-8C alkylene (interrupted by a sulfur atom), 3-(1-8C alkyl)-3-azapentane-1,5-diyl, 4-(1-8C alkyl)-4-azaheptane-1,7-diyl or 1-ethyl-2,2,6,6-tetramethylpiperidine-4,2'-diyl; and    Z2 = 2-12C alkylene, 4-8C cycloalkylene, 6-14C arylene, 4-8C cycloalkane-bis(1-4C alkylene), 6-14C arene-bis-(1-4C alkylene), 4-12C alkylene (interrupted by one or more oxygen atoms), 3-(1-8C alkyl)-3-azapentane-1,5-diyl or 4-(1-8C alkyl)-4-azaheptane-1,7-diyl.    An INDEPENDENT CLAIM is included for the compound (I), A is (i) -C(=O)-OR1a, -C(=O)-N(R2a)(R3a) or -SO2-phenyl (when n is 1) or (ii)-(iv).