Use REI Extreme Protection Sunblock SPF 50 for extra protection from the suns harmful rays. Includes titanium dioxide to protect sensitive areas of nose and cheeks plus, it protects in extreme conditions of high altitude and sunny days on snow. Features state-of-the-art polymers that allow the lotion to attach to the skin and therefore resist water and physically rubbing off. Bonds to the mid and top layers of your skin works best when applied to cool, dry skin 20 - 30 minutes before sun exposure. Hypoallergenic, waterproof, sweat-resistant, PABA-free, greaseless and fragrance-free formula provides UVA and UVB protection. Proper application gives lasting water- and sweat-resistance in most conditions all sunblocks should be reapplied to intense abrasion areas. Soap and water will remove the lotion, yet normal sweating and swimming will not.