Sunscreens are used to protect the skin from the harmful sun radiation. They help to prevent sunburn and premature aging signs (such as fines lines, wrinkles, leathery skin). Sunscreens also decrease the risk of skin cancers, sun light causing skin conditions called photodermatoses and skin reactions (sun or photo sensitivity) caused by some medications . It also gives an even tone to the skin. The active ingredients in sunscreens work either by absorbing (chemical sunscreen) the sun's ultraviolet (UV) radiation, preventing it from reaching the deeper layers of the skin, or by reflecting (physical sunscreen) the radiation. Wearing sunscreen does not give a hundred percent protection.
They are available in various forms (e.g., cream, lotion, gel, stick, spray, lip balm).
Sunscreens are only for skin use. The procedure is to apply sunscreen generously to all exposed skin 30 minutes before sun exposure. As a general guide, 30 grams is required to cover the entire body. Reapplication is necessary after swimming or sweating or drying off with a towel or if it has rubbed off. It acts for a maximum of 4 hours so repeated applications are needed. Sometimes the sunscreens themselves may cause allergic reactions.
In infants younger than 6 months it is best avoided. Protective clothing should be advised instead to the parents.
The sun produces two types of ultraviolet (UV) radiation, UVA and UVB. UVA radiation causes skin damage, premature aging, and skin reactions. UVB radiation causes sunburn. Both increase cancer risk. Most sunscreens protect against UVB radiation, but a sunscreen with both UVA and UVB protection (broad-spectrum coverage) should be chosen. Sun Protection Factor (SPF) is a rating that tells how much protection a product provides against sunburn. The higher the number, the greater the protection. An SPF of at least 15 is recommended. SPF 30 provides high protection against sunburn. Water-resistant products provide protection for up to 40 minutes of water activity or sweating and very water-resistant products protect for up to 80 minutes.
Water, sand, and snow reflect the radiation hence more chances of sun damage to the skin. In addition to sunscreen, protective clothing (e.g., hat, umbrellas, long sleeves/pants, sunglasses) when outdoors are advocated.
Applying sunscreen daily is crucial to maintaining healthy skin.