A connector includes a mask end for connecting with the interior of a respiratory mask, a supply conduit end, and a gas washout vent passage having an inlet adjacent to, or forming part of, the mask end in fluid communication with the interior of the respiratory mask and an outlet in fluid communication with atmosphere. The vent outlet of the vent passage is disposed on the side of the connector remote from the mask end. A respiratory mask includes a mask shell, a mask inlet for connecting with the outlet of a breathable gas supply conduit, and a gas washout vent passage. A vent outlet is disposed on the side of the mask remote from the mask interior and is adapted to direct the washout gas in a direction substantially parallel to the longitudinal axis of the mask inlet and away from the mask inlet.