n , n &# 39 ;- hydrocarbylenebisamic acid hydrazides ] and their derivatives are useful for stabilizing polymeric systems which are subject to degradation and / or discoloration upon exposure to heat and / or light . the novel compounds contain at least two hindered amine light stabilizing groups and two hydrazide or hydrazide derivative thermal oxidative stabilizing groups . the novel compounds are excellent light stabilizers for polyolefins , have low volatility and are not readily lost from polymeric systems via volatilization , migration or extraction .