The invention is directed to a valve for an aerosol container for dispersing a suspension or solution of a medicament in a liquid propellant contained therein. The valve comprises a valve body defining an aperture, a seal mounted at the aperture, and a valve stem having a dispensing passage. The valve stem being slidably moveable through the seal such that in a first position the valve is closed to prevent the medicament and propellant from entering the dispensing passage. The valve stem also being such that in a second position the valve is open to allow the substance to be dispensed through the dispensing passage. The valve stem characterized in that it is constructed from a mouldable plastic and a mouldable lubricant.