HALS + UVA Combined Package HUP-50

The benzotriazole UVA absorbs UV photons (290–380 nm) and dissipates energy as heat, preventing chromophore excitation in the binder. HALS operates downstream by scavenging the free radicals that do form, regenerating nitroxyl species catalytically. The two mechanisms address different failure pathways, so the combined package provides significantly longer gloss and color retention than either component alone at equivalent total loading.