Starting this summer, the labeling mumbo jumbo on sunscreens will be much easier to understand.

Buying sunscreen this summer is going to get a lot less misleading, thanks to new rules the Food and Drug Administration (FDA) issued last year. The rules go into effect this June and will change a lot about the way you navigate the sunscreen aisle.

At a recent dermatology conference, Vincent Deleo, MD, chairman of the department of dermatology at St. Luke's/Roosevelt Hospital Center in New York presented a rundown of what those new labels will mean for you.

• No more "sunblocks." The term "sunblock" is too misleading, the agency has decided, because no sunscreen can block 100 percent of the sun's ultraviolet (UV) rays. All products will simply be called sunscreens from here on out.

• No more SPF 100. After a huge number of product introductions claiming to be SPF 70, SPF 90, and even SPF 100, the FDA has decided that "SPF 50+" will be the highest rating allowed on a product. According to the American Academy of Dermatology, an SPF 15 product blocks 93 percent of UV rays, while an SPF 30 blocks 97 percent, so the amount of added protection you get from an SPF 75 or 100 is minimal. There is an exception to this rule, though: The FDA will allow an SPF of higher than 50 if the company can prove that a product provides more protection than SPF 50.

• Water-resistance ratings. Also gone will be words like "waterproof," "sweatproof," and "all-day protection," which the FDA believes are misleading. If a product can resist water, it must be labeled as either "Water Resistant (40 minutes)" or "Water Resistant (80 minutes)." One complaint among dermatologists is that products are advertised as offering all-day protection or as being waterproof, and people assume they can apply the product just once, whatever their sun exposure that day.

• A clear definition of "broad-spectrum." SPF applies only to UVB rays, which cause sunburn, not UVA rays, which cause sunburn as well as cancer and aging. "Broad-spectrum" sunscreens theoretically protect against both, but now they have to prove it. In order to bear the label, any product labeled SPF 15 or higher must meet wavelength tests to show that it protects against UVA rays. Products with a protection factor lower than an SPF 15 won't be allowed to bear the "broad-spectrum" label.

• Strict labeling of cancer risk. Products with an SPF lower than 15 and those that don't meet the criteria for "broad-spectrum" will have to be labeled with the following: "Skin Cancer/Skin Aging Alert: Spending time in the sun increases your risk of skin cancer and early skin aging. This product has been shown only to help prevent sunburn, not skin cancer or early skin aging."

In spite of the new labeling, the FDA isn't doing anything about the actual ingredients in sunscreens. The majority of sunscreens on shelves still rely on chemical sunscreen ingredients—oxybenzone, octisalate, octinoxate, and avobenzone—which are known hormone disruptors. Oxybenzone and avobenzone are also potential allergens. Other sunscreens contain mineral sunscreen agents, namely titanium dioxide and zinc oxide, often in nanoparticle form, and the safety of nanoparticles is still up for debate.

All that being said, applying sunscreens should be your third line of defense for sun protection, behind wearing protective clothing (stock up now on these sun-protective clothing items before the summer rush hits) and simply finding shade during the peak sun hours of 10 a.m. to 4 p.m.