Apparatus and method are disclosed for killing pathogens by sanitising volumetric spaces and the exposed surfaces of the walls, ceilings and floors of the spaces and the exposed surfaces of items within the spaces comprising generating a fine mist, containing a chemical to kill the pathogens, and dispensing it into the air in the spaces so that it contacts and kills all pathogens in the air and on exposed surfaces in the spaces. The surfaces may be those of inanimate objects and / or the skin, hair or clothing of persons or the skin, fur or feathers of animals or birds. A flow of air through the chamber may be provided to ensure that the mist is fully distributed throughout the spaces and onto all exposed surfaces therein. The volumetric spaces may be of any size and the sanitising mist may be generated either by stand-alone units, mobile units (which may be moved or parked as required) or by fixed spray nozzles. The preferred chemical killing agent is hypochlorous acid (HOCI) or a solution thereof. The apparatus and method of the invention is intended for use in ambulances, and sensitive areas, such as medical treatment areas, food preparation areas, scientific research areas or satellite assembly areas, bird or animal rearing houses, egg production houses or milking parlours, etc.
