Glass filters UV very effectively. The glass bulb of the fluorescent lamp removes most of the UV energy from the mercury arc that is not absorbed by the phosphor. An additional glass window will remove most of the remaining UV energy.

UF-3 Acrylic, manufactured by Rohm and Haas, Atohaas division, ICI Acrylics and others, can be used as lens material, both clear and opaque. Another product, UF-5, may be useful as well.

Note: Users of quartz halogen lamps should be aware that these lamps emit some UV; the quartz does not block UV radiation. Although this is very low energy, it may be a concern in some applications.