Abstract: A twist-off can end assembly has a cylindrical can body and a lid assembly. The lid assembly includes a joined lid and collar. When an open end of the can body is closed by the lid assembly, a sealing lip on the collar engages a flange on the can body to form a hermetic seal. An annular chamber adjacent the sealing lip is formed by the collar and flange. When pressure of the contents within the can body increase to a predetermined amount, gas escapes from the can interior to the annular chamber. When pressure within this annular chamber increases, the lip deforms to increase the seal between the lid assembly and can body. Therefore, a self-sealing can arrangement is obtained. The lid assembly can be readily unscrewed from the can body.