Shereene IdrissBoard Certified Derm, Founder and Chief Nerd

YouTube Channel

30 Jan 2026 · 1 min

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0:57

A short YouTube clip (board-certified dermatologist speaker) distinguishing UPF (a clothing/fabric rating) from SPF (a topical sunscreen rating), criticizing marketing of face masks labeled as sun-protective, and questioning what material treatments or infusions grant those masks a UPF 50 rating—arguing this requires study. The speaker emphasizes that not all fabrics equally block UVA/UVB and that UPF is distinct from SPF.

Chapters

My skin looks like it's shedding. This is not actually skin. It is a sunshield patch. Face masks with spf. Wrong. I'm a board certified dermatologist, and these are not face masks with spf. They are supposedly face masks with upf. And there is a difference between UPF and spf. Let's take a step back. UPF stands for ultraviolet protection factor, and it's a rating usually given to clothing that measures the clothing's ability to block UVA and uvb. Whereas SPF is sun protection factor, measuring the ability of a cream or some other product that you're putting on your face to protect your skin from UV rays. So the question of the hour is regarding these specific masks is what exactly are the masks infused with in order to protect your skin from the sun so that they can have a UPF rating of 50? Because not all fabrics are created equal, and that should actually be studied.