Sun protection goes by many names, but the term "sunblock" most often means products that contain an SPF protection intensity higher than 15. Sun protection is necessary to protect the skin, but it is important to note that no product provides 100 percent protection from ultraviolet sunlight.
Function
Sunblock does what the name implies; it blocks some of the sun's rays or radiation from being absorbed into the skin. It can also reflect the radiation. Sun rays are UVA, ultraviolet A, or UVB, ultraviolet B, depending on their wavelength. Sunblock has a sun protection factor, SPF, which tells the consumer how long it will stay effective on the skin. A broad spectrum sunblock means it protects against UVA and UVB rays.
Ingredients
Sunblock ingredients vary between manufacturers, but many have chemical and physical agents included. Chemical agents absorb the energy of the UV rays prior to them affecting the skin. They are also absorbed in the skin and work mainly on UVB rays. Chemical sunblocks come in combination forms and have multiple chemical ingredients. Physical agents reflect or scatter the rays before they affect the skin and sit on the skin. They work on UVA rays as well. The most common physical agent ingredients are zinc oxide and titanium dioxide.
Application
Sunblock should be applied prior to being out in the sun. Ideal application time is at least half an hour before being outdoors. For water-resistant sunblock, it should be reapplied often and at least every two hours, including after swimming or toweling off. Apply sunblock generously and to all areas of the body that will be exposed. Take care to apply sunblock to areas that may be forgotten, including the hands, tops of the feet and ears. Sunblock should be a part of the everyday routine, not just when outdoor activities are planned.
Benefits
UVA and UVB rays are known to cause skin damage and problems such as skin cancer, wrinkles, lines and changes in the texture of the skin. Sunblock provides the first line of defense from these damaging rays. Sunblock provides protection against sunburn. Experiencing a bad sunburn at a young age can lead to health problems later. Sunblock protects the skin even on cloudy days. Another benefit is that broad spectrum sunblock also protects skin from phototoxic damage and sun rashes.
Considerations
Remember that SPF is not a measure of how long to be out in the sun as the benefits of all sunblocks decrease over time. Your skin type, which means how likely your skin is to burn; how much and how often sunblock is applied; and the intensity of the UV rays all affect how much protection sunblock offers. The humidity level and sweating can also make sunblock less effective. Sunblock can also contain ingredients such as fragrances or other additives that can cause allergic reactions, so check the label before purchasing.
