"Sun Protection Factor" (SPF) is one of those distractions whipped up by the cosmetics industry to impart a sense of agency within an arbitrary set of choices. Specifically, SPF refers to the number of hours the product is designed to work, not the degree to which it works. Given the length of the day, then,
All sunscreens and blocks will protect you to some degree against burning, provided you apply early and often (which may be the reason you're burning). Sunscreens contain chemical filters that protect the skin from the sun's rays; sunblocks, though, also serve as a physical barrier to the rays, so are much hardier in this respect.
So, if you want protection against the real enemythe long-wave UVA rays that cause aging and skin cancerlook for a sunblock with Parsol 1789 (also known as avobenzone), zinc oxide, or titanium dioxide. These are the only active ingredients that block harmful long-range UVA rays, and they are included in surprisingly few products. Of the various drawbacks to the three, zinc oxide is the Marcel Marceau-esque nose cream you see lifeguards wearing, avobenzone can sweat off easily and possibly cause irritation, while titanium dioxide can block pores and feel heavy. But all will do a better job of keeping your collagen fibers from becoming busted bedsprings than most of the creams designed to keep you from burning.
Our mission to inspire readers to get outside has never been more critical. In recent years, Outside Online has reported on groundbreaking research linking time in nature to improved mental and physical health, and we’ve kept you informed about the unprecedented threats to America’s public lands. Our rigorous coverage helps spark important debates about wellness and travel and adventure, and it provides readers an accessible gateway to new outdoor passions. Time outside is essential—and we can help you make the most of it. Making a financial contribution to Outside Online only takes a few minutes and will ensure we can continue supplying the trailblazing, informative journalism that readers like you depend on. We hope you’ll support us. Thank you.Contribute to Outside →