A container comprises a releasable metal closure formed with an end wall and a depending skirt and having an annular layer of sealing compound provided on the inside of the end wall adjacent the skirt and a container body comprising a neck with an annular sealing surface surrounding a circular opening and adapted to seal against the annular layer of sealing compound over an annular sealing interface in the closed position of the closure on the container body. The container body and the closure are formed with no mechanical means for coupling them together to form or maintain a seal therebetween and the seal is provided by a partial vacuum formed in the container during processing. The annular sealing surface of the container body is formed with a localized protrusion or recess which provides a discontinuity in the annular sealing interface, whereby relative rotation of the closure and container body from the closed position creates a venting path from the interior of the container body to the exterior so that the seal is broken and the closure is released.