Early SPF products were designed to block the sun’s measurable UVB rays, which causes
ordinary sunburn. Many of today’s topical SPF products also block UVA rays. These
products contain one or two types of compounds:
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Organic chemical compounds that absorb ultraviolet light (chemical SPFs)
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Opaque materials that reflect light (physical SPFs, usually metallic oxides).
The Food and Drug Administration (FDA) rates sunscreens according to sun protection
factor (SPF) and water resistance.
The SPF, assigned by an independent laboratory, indicates how many times longer a
person wearing a given sunscreen will take to sunburn than without it. However,
using it does not mean the wearer is safe from all sun exposure impacts. The American
Cancer Foundation and The American Association of Dermatologists recommend a minimum
SPF 15 with broad spectrum protection for most people. Higher SPF levels are recommended,
however, for individuals with lower Fitzpatrick scale indexes and for clients undergoing
treatment for skincare disorders and corrections.