Sandbox:Sara

Measurement of UV protection afforded by sunscreens and clothing

Measurement system	SPF (Sun protection factor)	UVA‐PF (UVA‐protection factor)	UPF (Ultraviolet protection factor)
Definition
Developed for	Sunscreens	Sunscreens
Global acceptance	International
UV wavelengths protected	UVB
Examples	SPF 2 protects against 50% UVB SPF 8 protects against 88% UVB SPF 15 protects against 93% UVB SPF 30 protects against 97% UVB SPF 50 protects against 98% UVB

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]