A tap for sterilising water, the tap comprising an inlet, a source of ultraviolet radiation, a sterilisation zone and an outlet, the outlet consisting of one aperture through which the water exits the device, wherein the source of UV radiation is positioned in the sterilisation zone such that substantially all of the internal surfaces of the outlet portion can be directly irradiated by the source of ultraviolet radiation, and wherein the source of ultraviolet radiation and the aperture are arranged such that no ultraviolet radiation can be transmitted directly from the source of ultraviolet radiation through the aperture to leave the device.
