Welcome to spf short term finance. Theoretically applying sunscreen with a sun protection factor or spf of 100 would allow beachgoers to bare their skin 100 times longer before suffering a sunburn. Elta Md Uv Replenish Broad Spectrum Spf 44 Poway Dermatology We asked some sun care experts to break down how sun protection factors are calculated and how to best apply the stuff.
