A waste processing machine for reducing waste material and having a safety device for shearing lines. A housing defines a cutting chamber and an intake opening in communication with the cutting chamber for receiving waste material. A disc is disposed in the cutting chamber, rotates about an axis, and has an axial surface facing the intake opening. A cutting member is fixed to the disc for revolution about the axis concurrent with rotation of the disc for reducing waste material. A cutting anvil is coupled to the housing adjacent to the intake opening and faces the axial surface of the disc for reducing waste material between the cutting anvil and the cutting member. A line shear element is attached to the housing, extends into the cutting chamber toward the axial surface of the disc, and is spaced from the cutting anvil for shearing lines caught by the rotating disc.