ADP, Timberline, and Marquis vanities are made from high moisture resistant MDF (also known as HMR MDF) from Laminex or Polytec.
Are they waterproof:
Although the highest quality Australian moisture resistant board is used in the carcase and doors/drawers and the exposed edges of the board are sealed with edge tape and paint, there is still no way to make a vanity fully waterproof. The best way to ensure your product lasts a lifetime is, if any water sprays or is spilled into or on the cabinet, simply wipe it off with a cloth so the moisture doesn’t have a chance to be absorbed by the timber.