Sunscreen: Water Resistance

Because no sunscreen is 100% impervious to moisture, the FDA no longer allows a product to claim itself “waterproof” or “sweat proof” without proper testing.  Sunscreens on the U.S. market today can now only claim “Water Resistant (40 minutes)” or “Water Resistant (80 minutes)” after conducting this 3rd party test:  the appropriate amount of sunscreen is applied to a person’s arm then submerged in Jacuzzi-like conditions for 40 or 80 minutes (in intervals of 10 minutes in and 10 minutes out), then the SPF levels are measured.  If the amount of sunscreen left on the arm still protects at the SPF listed for the product, it is allowed the water resistant claim.

This does not mean you can stay in the water for 40 or 80 minutes, it simply means that after 40 minutes (or 80 minutes) the SPF may start to decline and you need to reapply to maintain that SPF.  It is always recommended that you reapply after swimming, sweating or towel drying.

Enjoy the sun!