How sun lotion protects your skin? Sunscreen (also known as sunblock, suntan lotion) is a lotion, spray or other topical product that helps protect the skin against the sun's ultraviolet rays (UV), and which reduces sunburn and other skin lesions in order to reduce your risk of skin cancer. However, in the United States, the term suntan lotion usually means the opposite of sunscreen, and instead refers to lotion designed to moisturize and maximize UV exposure and tanning rather than block it. They are commonly called indoor tanning lotions when designed for use with tanning beds or just suntan lotion if designed for outdoor use and may or may not get an SPF in them.
The most effective sunscreens protect against UVB rays (ultraviolet rays of wavelengths between 290 and 320 nanometers), which can cause sunburn, and UVA (between 320 and 400 nanometers), which damages the skin with longer-term effects, such as premature skin aging. Most sunscreens work containing either an organic chemical compound that absorbs ultraviolet light (such as oxybenzone) or an opaque material that reflects light (such as titanium dioxide, zinc oxide), or a combination of both. Typically, absorptive materials are called chemical blocks, whereas opaque materials are mineral or physical blocks.
Contrary to common opinion that sunscreen should be reapplied every 2-3 hours, research has shown that the best protection is achieved by the application 15-30 minutes before exposure, followed by a new application 15-30 minutes after sun exposure begins. more reapplication is necessary after activities such as swimming, sweating and friction.
Sun Protection Factor
The SPF of a sunscreen is a laboratory measurement of the effectiveness of sunscreen, the higher the SPF, the more protection a sunscreen offers UV-B (ultraviolet radiation that causes sunburn). The SPF indicates the time a person can be exposed to sunlight before getting sunburn with sunscreen applied relative to when they can be exposed without sunscreen. For example, someone who would burn after 12 minutes the sun would expect to burn after 2 hours (120 min) if protected by a sunscreen with SPF 10. In practice, the protection of a sunscreen especially depends on factors such as:
The skin type of the user.
The amount requested and the frequency of the new application.
Activities of the person concerned (for example, swimming leads to a loss of sunscreen the skin).
Amount of sunscreen the skin has absorbed.
The SPF is an imperfect measure of skin damage because invisible damage and skin aging is caused by the very common ultraviolet type A, which does not cause redness or pain. Conventional sunscreen does not block UVA as effectively as it does UVB, and SPF 30 + may translate into a significant reduction in the protection against UVA, according to a 2003 study. According to a 2004 study, UVA also causes DNA damage to cells deep in the skin, increases the risk of malignant melanoma. Even some products labeled "broad spectrum UVA UVB /" does not provide good protection against UVA rays. The best UVA protection is provided by products that contain zinc oxide, avobenzone and Mexoryl.
Due to consumer confusion about the extent and duration of protection offered, labeling restrictions in force in several countries. In the United States in 1999, the Food and Drug Administration (FDA) decided to establish the labeling of SPF 30 + for sunscreens offering more protection and a similar restriction applies in Australia. This was done to discourage companies from making unrealistic demands on the level of protection (such as "all day protection"), and because an SPF over 30 does not provide significantly better protection.
The SPF can be measured by applying sunscreen to the skin of a volunteer.
Posted on February 8, 2010.
