The 30-Minute Sunscreen Rule
Photo: Duke Plofker
We’ve debunked SPF myths, asked if your hair really needs sun protection, and even found the right sunglasses to protect your eyes from the sun. But there’s one big question left: how much sunscreen and how often do you need to apply it when you’re actually swimming? Here, a refresher on sun care, from how long in advance of swimming it should be applied to which ingredients your bottle should contain.
Procter & Gamble Senior Scientist Laura Goodman notes that the broad-spectrum designation is the first thing you want to see on your sunscreen bottle. “Turn the bottle over and look at the ingredients for avobenzone. If it has that, it’s truly broad spectrum. Keep in mind avobenzone is for chemical sunscreen. For physical/mineral sunscreens, look for titanium oxide or zinc oxide.”
How much should you apply to body? Dr. Neal Schultz says that “traditional” (carbon-based) sunscreens require at least one ounce (a shot glass) for body and face, or a teaspoon-size for face only. “For chemical-free sunscreens, 1/3 to 1/2 as much because they spread much better and cover larger areas,” he specifies.
When it comes to your morning skin-care routine, the order of application can become confusing. Should you layer on SPF before or after your moisturizer and serums? Goodman says after. “Your UV protection should be the last thing you do. You want the goodies in your serum and moisturizers to get to your skin first. SPF is like an umbrella.”
Schultz says traditional (carbon-based) sunscreens should be applied 30 minutes before sun exposure. “‘Chem-Free’ sunscreens, also called physical blockers because they contain Zinc oxide and/or Titanium Dioxide, work immediately upon application which is one of their many advantages, so smear and swim!” he says.
As for the best time to reapply, Dr. Valerie Goldburt advises a conservative strategy: “I’ve heard that sunscreen can last up to 80 minutes while swimming, but I don’t believe that. I’ve seen people with sunburns after applying sunscreen and swimming for a half hour. So you should reapply after 30 minutes,” she explains. Dr. Gervaise Gerstner says sunscreen can last up to 80 minutes, but it’s important to read the sunscreen bottle. Her 80-minute SPF pick is L’Oréal Paris’ Advanced Suncare. “The FDA mandates that companies print how long sunscreens are water-resistant (note: not waterproof) on the bottle,” says Gerstner. “Even after a ten-minute swim, you should reapply after 50-80 minutes. If you feel as if you have wiped off your sunscreen when drying with towel, then use good judgment and reapply.”
Says Goldburt, “Keep in mind that sunscreen can break you out, so be sure to wash it off when you’re out of the sun. Try Dial Acne Control body wash, which will not only cleanse your skin of sunscreen, but also help prevent breakouts.”
