Fiberglass insulation holds up quite well to UV-C. The UV-C will not affect the “glass” component in the insulation, it can affect the binders in the insulation, but overall we tend to not worry about insulation if it is glass based. Same thing can be said for filters, i.e. synthetic filters will get eaten up by the UV-C, but glass-based filters (e.g. HEPA) hold up to UV-C.