FEP is both transparent to UVA and UVC light and totally resistant to it, as well as being temperature resistant. Therefore, it makes an excellent material for shatterproofing UVA and UVC lamps.
The FEP coating will outlast the life of the lamp, where other inferior plastic coverings embrittle or discolour under the effect of the UV radiation. If the lamp suffers damage the glass is contained in the shrunk-on jacket.
Loss of UVA and UVC light is much less than with other polymer coatings. For our usual shatterproof lamp coatings, loss of UVA is around 4% and UVC is 11%. We know of no other suitable flexible coatings that provide a smaller loss of UV.
We recommend that lamps are changed after the manufacturer’s specified working hours as the output does deteriorate over time.