How’s Your SPF Vocab?

With the plethora of sunscreen options now available at your fingertips, the myriad of choices can be confusing. To help you decipher what the labels mean, and which product may be best for you, the following is a cheat-sheet of sorts to expain the most commonly used terms and abbreviations.


Short for Ultraviolet-A, these rays penetrate deep into the skin and are the largest cause of premature skin aging and wrinkles–also known as photoaging. They can also contribute to skin cancer as well as a suppressed immune system.


Short for Ultraviolet-B, these rays are the chief cause of skin reddening and sunburn and tend to damage mainly the skin’s surface. They are the most significant contributing factor to skin cancer.


Short for sun protection factor, this abbreviation followed by a number indicates how many times longer it will take for sunscreen-protected skin to burn than unprotected skin. For example, an SPF 15 sunscreen means it will take 15 times longer to burn than if you weren’t wearing any sun protection.

Pro Tip: An SPF factor of 15 is the minimum needed to prevent skin damage from UVB.

Broad Spectrum

Broad Spectrum is an all-protective form of sunblock which protects against both UVA and UVB rays. The sun protection factor, or SPF number, refers only to UVB protection.

Pro Tip: Wearing broad-spectrum protection every day, even on cloudy days or days you’ll spend inside, is the key to keeping skin healthy and avoiding premature aging.

Physical Sunscreen

Physical sunscreens create an impenetrable shield against the sun’s rays and are made with zinc oxide or titanium dioxide. The particles in these ingredients sit on top of the skin and reflect all UV rays.

Pro Tip: These tend to be less irritating to the skin than chemical sunscreens. This is particularly beneficial for kids and individuals who have sensitive skin.

Chemical Sunscreen

Chemical sunscreens contain organic, carbon-based compounds that create a chemical reaction to convert UV rays into heat, which is then released from the skin without burning.

Pro Tip: Chemical sunscreens can take up to twenty minutes to absorb into the skin, so make sure to give yourself the appropriate amount of time to let it soak in.

Water Resistant

In the USA, the FDA only allows two claims, Water Resistant (40 min) or Water Resistant (80 min). These retain their stated SPF value for the specified time, in water or while sweating.

Pro Tip: Be vigilant about reapplying approximately every two hours or more frequently if you’re sweating / swimming, even if the product claims to protect for a longer amount of time.