Look for product called Trespa Athlon.
It's Resin based fibre board that is very muck like Pnenolic board but with laminate face. Completely resistant to moisture, chemicals, heat. It's used in place like swimming cubicles, counters for Labs etc.
It can even be drilled an tapped. I use it for Spoil board on my own machine which is constantly covered in cutting fluid. All work is help down by drilling and tapping directly into it or by clamping using holes tapped into it.

Not cheap but extremely resistant and tuff stuff. Nothing better for bed IME.