An aerosol generator ( 1 ) has a generally cylindrical body with a mouthpiece at one end a canister ( 6 ) removably received within the body, the canister containing pressurised fluid, an interior, continuous canister valve ( 8 ) and a depressible discharge tube ( 12 ) that releases the fluid into the body. An electrically operable valve ( 14 ) controls the discharge of the fluid from the canister towards the mouthpiece, and a nozzle forms an aerosol of the fluid that discharges from the canister. A pressure switch ( 17 ) switches in response to a pressure reduction at the mouthpiece and supplies electrical power from internal batteries ( 15 ) to the valve to produce a discharge of the fluid through the valve to create an aerosol in the mouthpiece for the consumer.