Abstract: At 07:15 a.m. on October 19, 2019, an employee was standing on scissor lift and replacing insulation on the pipes in the engine room of Building 3. As the employee was lowering the scissor lift, the walking platform of the scissor lift where a technician was standing, struck the service drain valve (3ML 3064) and cracked the nipple at the thread causing an uncontrolled release of pressurized anhydrous ammonia. The employee was able to dismount the scissor lift from its initial position and evacuate the engine room. A coworker immediately notified the refrigeration personnel of the ammonia release, who responded to the incident and isolated the service drain valve. The employee sustained first and second degrees burn to the lower leg and was treated but not hospitalized.