Bis-phosphite stabilized compositions

A stabilized composition which comprises

• (A) an organic material subject ot oxidative, thermal or actinic degradation, and
• (B) an effective stabilizing amount of a bisphosphite of formula I, or III ##STR22## wherein n has a value of 0 or 1;
• when n is 0, Q is a direct bond,
• when n is 1, Q is --CR.sup.1 R.sup.2 wherein each R.sup.1 and R.sup.2 independently represents hydrogen, straight chain alkyl of 1 to 18 carbon atoms, branched chain alkyl of 1 to 12 carbon atoms, phenyl, tolyl or anisyl;
• each Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4, Z.sup.2, Z.sup.3, Z.sup.4 and Z.sup.5 independently represents hydrogen, a straight or branched chain alkyl of 1 to 18 carbon atoms, bicycloalkyl of 7 to 10 carbon atoms, phenyl, benzyl, 1-phenylethyl, cyclohexyl, 1-methylcyclohexyl, cyano, halogen, nitro, trifluoromethyl, hydroxy, amino, alkanoyl of 2 to 18 carbon atoms, alkoxy of 1 to 18 carbon atoms or E.sup.1 E.sup.2 E.sup.3 Si where E.sup.1, E.sup.2 and E.sup.3 are independently hydrogen, alkyl of 1 to 4 carbon atoms or phenyl;
• each Z independently represents alkyl of 1 to 18 carbon atoms, phenyl or said phenyl mono- or di-substituted by alkyl of 1 to 8 carbon atoms or 1-phenylethyl;
• or by cyano, halogen, nitro, trifluoromethyl, hydroxy, amino, alkanoyl of 2 to 18 carbon atoms, alkoxy of 1 to 18 carbon atoms or E.sup.1 E.sup.2 E.sup.3 Si where E.sup.1, E.sup.2 and E.sup.3 are independently hydrogen, alkyl of 1 to 4 carbon atoms or phenyl;
• and
• Z.sup.6 and Z.sup.7 are independently hydrogen, a straight or branched chain alkyl of 1 to 18 carbon atoms, phenyl, said phenyl substituted by alkyl of 1 to 8 carbon atoms;
• or are independently benzyl, 1-phenylethyl, cyclohexyl, 1-methylcyclohexyl, cyano, halogen, --NR.sup.3 R.sup.4, and --SR.sup.5 where R.sup.3, R.sup.4 and R.sup.5 are independently hydrogen, a straight or branched chain alkyl of 1 to 18 carbon atoms, phenyl, benzyl, cyclohexyl or 1-methylcyclohexyl.