The disclosure relates to a portable apparatus for decontaminating an enclosed room or other space comprising a passageway (17) having an air inlet at one end and an outlet at the other end. A pump (12) to cause a flow of air through the passageway from the inlet to the outlet. A heater (13) to heat the air flowing through the passageway to a predetermined temperature, and a flash evaporator (14) in communication with the passageway. Liquid decontaminant is pumped (16) from a supply (15) of decontaminant to the evaporator (14) to be evaporated and for the evaporant to be delivered to the air flow in the passage (17) to flow in the air flow from the outlet to the rooms to be decontaminated. A universally rotating nozzle (18) is provided at the outlet to distribute the decontaminant containing air throughout the enclosure.
