An extraction system for removing unpleasant odor includes a housing having front and rear walls and side walls interconnecting the front and rear walls. The depth of the housing from the front to the rear wall is substantially less than distances across the front and rear walls from one side to the other thereof. A centrifugal fan is mounted to the housing with an axis of the fan being perpendicular to the rear wall. The fan has an axial air inlet located centrally of the front wall for receiving odor-laden air and an air outlet from the fan is tangential to the fan and coupled to discharge air to atmosphere from the extraction system. An absorbent filter unit is located within the housing downstream of the fan and includes an absorbent mass and a perfume source. Air discharged to atmosphere is both substantially free of the odor and scented via the absorbent filter unit.