The testing concluded that 5/8” USG Sheetrock Brand EcoSmart Panels Firecode X (UL Type ULIX) and USG Sheetrock Brand EcoSmart Panels Mold Tough Firecode X (UL Type ULIX) is specified in more than 260 fire-rated wall, column, and floor- and roof-ceiling UL designs in which Type X or Type C panels are required. That means that ULIX can be used as a replacement for Type C panels – helping to reduce jobsite confusion and increase productivity.