Abstract: A vacuum cleaning system having a receptacle of non-porous material, such as a plastics bag (65), adapted to safely receive and hold hazardous material such as asbestos fibre. Vacuum is applied by a fan (86) to a suction chamber (69) and then through a filter (71) to an intermediate chamber (63) and via a suction pipe (61) to the bag (65). Waste material is sucked into the bag through an inlet pipe (67). The filter is cleaned periodically by admitting atmospheric air through a pulse valve (74) causing an inrush of air through the filter (71) and into the bag (65), cleaning the filter and intermediate chamber (63).