An employee was performing a gaging around, checking outside operating conditions, and inspecting the equipment in the pharmaceutical unit. A pressurized hose connected to a process line and containing a contaminated chemical mixture of nitrogen and hydrochloric acid was nearby. The hose was pressurized but not flowing; it was closed by the valve. The employee was 3 to 5 feet from the hose when it became disconnected. He sustained burns to his abdomen, arm, and face.