This so much. People will use plexi on flexing stuff,and it will shatter and cause severe injury. From my experience it gets as sharp as single pane, non tempered glass when it shatters! Ouch!For everyone's clarification on acrylic/plexiglass vs polycarbonate/lexan:
Acrylic aka plexiglass chips and shatters easily, though it'd be better than the safety of a glass sheet
Polycarbonate, also commonly known under the brand name Lexan, does not shatter, and is quite a bit more durable.
They both look very similar, make sure you know what you're buying or repurposing.