"Andrew Gabriel" wrote in message
...

I hope the unit has interlocks to prevent you looking at the
tube operating, which is dangerous. However, if you are tempted
to try defeating the interlocks, put a sheet of glass (not
plastic) between you and the lamp, stand well back, and only
operate the lamp for a few seconds. There is normally a dim
visible glow from the clear tubes.


I would have thought most plastics would block UV more than glass. Most UVB
and almost all UVC are blocked by virtually any material apart from quartz.