Extremity Injuries in Precast Concrete Manufacturing National Precast Concrete Association / NPCA Blog / Safety / Bi-Monthly Safety Training / Extremity Injuries in Precast Concrete ManufacturingFebruary 22, 2021 Leave a Comment The Safety Committee prepares bi-monthly safety training programs for precasters to use for conducting safety programs at their plant. This month’s featured safety program is on extremity injuries. Click on the links below to view the materials. Extremity Injury Powerpoint. Extremity Injury Supplemental Document.