A mill maintenance technician was injured because he was unable to verify if the hydraulic system he was working on was at "zero energy state" . . . A mill maintenance technician, with some hydraulic training, was injured in an accident at a sawmill. The accident occurred when he was in the process of removing a hydraulic cylinder from a production machine to replace the gland seals that were reportedly leaking. When he loosened the hose-end connector to remove the hose from the closed-end of the cylinder, a stream of oil unexpectedly discharged from the connector at extreme velocity, striking him in the face. The oil penetrated his cheek, and spilled into his mouth. The victim continued to work, and did not report the incident to his supervisor. He said that the taste of hydraulic oil remained in his mouth for approximately three days after the accident, as it secreted into his mouth from the pinhole-sized wound in his cheek.