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.
Definition. Sun allergy is a term often used to describe a number of conditions in which an itchy red rash occurs on skin that has been exposed to sunlight.The most common form of sun allergy is polymorphic light eruption, also known as sun poisoning.Some people have a hereditary type of sun allergy.Others develop signs and symptoms only when triggered by another factor â such as a medication or skin exposure to a plant such as wild parsnip or limes.he most common form of sun allergy is polymorphic light eruption, also known as sun poisoning. Some people have a hereditary type of sun allergy. Others develop signs and symptoms only when triggered by another factor â such as a medication or skin exposure to a plant such as wild parsnip or limes.