X-Block® is a lead-free plasterboard developed to provide protection against X-ray radiation such as X-ray diagnostic rooms within medical facilities and dental clinics. With the barium sulphate core, the X-Block® Radiation Shielding System forms an effective barrier against X-ray radiation. jointing compound must be used in conjunction with X-Block® plasterboard to provide a uniform X-ray radiation barrier. also offers high sound insulation performance and fire ratings.