Cam upon this video on my home page. YouTube Scientist Brainiac75 shows us why halogen lamps need to have protective glass.
https://www.youtube.com/embed/qNpF8rB5sNc

He mainly speak about the UV radiation from halogen lamps, which here in Israel, lots of people warned from it.
But the intensity of the UVB and UVC radiation is very low compared to UVA. Are they still can damage the skin and eyes?

The UVB starts to appear at levels exceeding the "safe limits", therefore it is considered as "not safe". But (unless I misunderstood the concept) the limits are based on an exposure from very small distance (based on what could be a typical arrangement with home lighting, like desk lamps or so), I doubt anyone will be so close to such high power halogen lamp, just due to the heat alone.

But there are other risks involved, which also are calling for a sturdy cover glass, mainly the disintegration of the hot tube and the consequent hot shower posing a fire risk when the lamp fails (and that include the case of being damaged by an external effect). So I would still consider operating such high power lamp without any cover as unsafe...