sun protection factor

Lotion bottle number

Sun protection factor is a measure of how well a sunscreen blocks ultraviolet radiation, specifically UVB rays that cause sunburn.

The number indicates how much longer skin can be exposed before burning compared to unprotected skin—SPF 30 theoretically allows thirty times longer exposure.

Higher numbers offer diminishing returns: SPF 30 blocks about 97% of UVB rays, SPF 50 about 98%.

Usually abbreviated SPF: Look for at least SPF 30.

SPFUltraviolet defense measure
sunblockUV-protective skin cream
sunscreenUV-blocking skin cream
mineral sunscreenUV barrier using minerals
skin cancerMalignancy of the dermis

broad-spectrum · photoaging · dermatology · UV radiation · zinc oxide · titanium dioxide · oxybenzone · water resistance · beach day · sunburn · melanin · pale skin · erythema · DNA damage · reapplication · grade · degree · antioxidants

Opposites

protection level

sun protection factorUV exposure

Contact with ultraviolet light

photosensitivity · sun damage

sun exposure intent

sun protection factortanning oil

Skin oil for darkening

sunbathing · tanning bed · sun worship

protection vs. exposure

sun protection factortanning oil

Skin oil for darkening

photosensitivity · sun exposure

Family

sun, suns, sunny, sunlight, sunlit, sunshine, sunned, sunning, protect

Familiarity: Top 500,000
Profile: Known to kids · Used worldwide · Timeless · Everyday, not technical · Rated G