SPF measures sunscreen protection from UVB rays, the kind that cause sunburn and contribute to skin cancer.
SPF does not measurehow well a sunscreen will protect from UVA rays, which are also damaging and dangerous.
Dermatologists recommend using a SPF15 or SPF30 sunscreen. Higher SPFs don't give much more protection.
SPF, or Sun Protection Factor,is a measure of how well a sunscreen will protect skin from UVB rays, the kind of radiation that causes sunburn, damages skin, and can contribute to skin cancer.
The SPF (Sun Protection Factor) scale is not linear:
So, one way of looking at this is that SPF 30 sunscreen only gives you 4% more protection than SPF 15 sunscreen.
Or, another way of looking at it is:
So, while you may not be doubling your level of protection, an SPF 30 will block half the radiation that an SPF 15 would let through to your skin.
It’s complicated, but to keep it simple, most dermatologists recommend using a SPF 15 or SPF 30 sunscreen.
Why not use a really high Sun Protection Factor? Sunscreens with really high SPFs, such as SPF 75 or SPF 100, do not offer significantly greater protection than SPF 30 and mislead people into thinking they have more protection than they actually do. Additionally, in order to have broad spectrum protection, the UVA protection should be at least 1/3 of the UVB protection. High SPF sunscreens usually offer far greater UVB than UVA protection, thus offering a false sense of full protection.
All sunscreens must undergo FDA approved SPF testing in order to make a UVB claim. There are three main types of SPF testing; SPF Static, SPF Water Resistant 40 Minutes, and SPF Water Resistant 80 Minutes.
All sunscreen manufacturers must adhere to the exact same FDA approved tests, ensuring that the SPF claims are consistent across all sunscreens, chemical and mineral. All SPF testing is conducted in vivo (with human subjects).
Badger sunscreens are tested according to the FDA monograph, Colipa (EU), and Australian requirements.