A flush valve is a mechanism used to flush a toilet or urinal. The valve and associated hardware are located within the toilet tank or in the body of the urinal. Most toilets have a lever or push button activator, which is used to operate the flush valve.
Photosensitivity (or sun sensitivity) is inflammation of the skin induced by the combination of sunlight and certain medications or substances.This causes redness (erythema) of the skin and may look similar to sunburn.hotosensitivity (or sun sensitivity) is inflammation of the skin induced by the combination of sunlight and certain medications or substances.
Photosensitivity, sometimes referred to as a sun allergy, is an immune system reaction that is triggered by sunlight.Photosensitivity reactions include solar urticaria, chemical photosensitization, and polymorphous light eruption and are usually characterized by an itchy eruption on patches of sun-exposed skin.hemical photosensitivity. Over 100 substances, swallowed or applied to the skin, are known to cause sun-induced reactions on the skin. A limited number cause most reactions (see Some Substances That Sensitize the Skin to Sunlight).