Glass blocks UV light. This is why EPROMS were made
with quartz windows
even though glass would have been much cheaper. Regular acrylic plastic
will block UV as well, but special types are available that allow
transmission of UV (such as for sun room roof panels and tanning beds).
My other concern with Plexi-Glass, and this could be completely unfounded,
is that would it etch or get damaged by high concentration peroxide?
-Ali