Customize Your Sun Protection Strategy
by Genevieve Monsma

In the sun for an hour or more?

Maybe you’re training for a marathon, keeping the garden beautiful or just puttering around outside your weekend home. Whatever the reason, if you’re out for an hour or longer while the sun’s shining, you need serious protection, experts say. Every doctor we spoke with recommended scalp-to-toe coverage with a sun-shielding product that’s water resistant (to minimize rub-off), an SPF of 30 (or higher) and “broad spectrum” coverage. (Broad spectrum, indicated on the label, means the product blocks skin-burning UVB rays as well as skin-aging UVA rays. Both types of rays can cause skin cancer.) And don’t assume your clothing is sufficient coverage. “A typical white T-shirt has about an SPF of 3, providing little protection against UVB rays and virtually no defense against UVAs,” says Macrene Alexiades-Armenakas, MD, PhD, a New York City dermatologist and scientist.

For outings longer than an hour, most doctors also advocate choosing a formula that contains UVA-blocking ingredients, such as zinc oxide or titanium dioxide. Called physical blockers, these ingredients literally shield your skin from rays, just as the walls of your house do, and they remain stable in the sun. By contrast, chemical sunscreen ingredients, such as Parsol 1789 and avobenzone, absorb rather than block UVA rays. They too are effective at minimizing UVA exposure, but studies show that some products can become destabilized after prolonged sun exposure. If the formula you choose contains only chemical sunscreen, you must re apply it every two hours to ensure protection. And when you’re in and out of water or sweating a lot, you should reapply any sun protection every two to three hours, whether it’s a chemical or physical formula.