Lavatory seat ventilation system

A seat for a lavatory pan, which is adapted to be hingedly joined to the pan, the seat having a thickness, an underside, and a rear edge, and includes within its thickness a C-shaped cavity which is open to the underside of the seat, and further comprises a deodorizing filter and an electrically powered motorized fan housed in the cavity, an air inlet opening through which air can pass into the cavity, an air outlet situated in the rear edge of the seat by which odor-free air can exit after being drawn through the filter by operation of the fan, a hinge by which the seat is attachable to a rear of the pan and a flat C-shaped cover plate removably secured to the underside of the seat to cover the cavity and retain the fan and filter in place, thereby creating a filter containing region of the cavity, the cover plate being removable when it is necessary to give access to the cavity, wherein the C-shaped cavity includes two sockets, one socket being located at one end of the C-shaped cavity and the other socket being located at an opposite end of the C-shaped cavity, and the cover plate includes two tongues which in use extend into the sockets in the ends of the C-shaped cavity, each tongue defining with its socket a tortuous path for air into the filter-containing region of the cavity, and each path comprises an air inlet to the cavity.