New labeling laws aim to take the mystery out of buying and using sunscreens.

RODALE NEWS, EMMAUS, PA—Buying a bottle of sunscreen nowadays is about as confusing as reading the list of unpronounceable ingredients on its label. What's printed on the front of the bottle doesn't help: waterproof or not waterproof? Is SPF 100 really necessary? What does "broad spectrum" protection mean? And what's the difference between UVA and UVB, anyway? The Food and Drug Administration (FDA) released new rules this week aimed at make sunscreen labels easier for consumers to understand. Currently, sunscreen standards relate to UVB sun exposure, the primary cause of sunburns and a contributor to skin cancer and premature aging. Under the new rules, the sunscreens will also have to be tested and labeled to disclose UVA protection. Radiation from this type of sun ray is more deeply penetrating, passes through windows, and is linked to skin cancer and early aging.

THE DETAILS: While this should certainly clear up some of the confusion surrounding sunscreen protection, it's important to note that bottles on shelves this summer will likely not offer this useful information; companies aren't required to make FDA-mandated changes to bottle labels until summer 2012. Nonetheless, some manufacturers may comply earlier.

The FDA says sunscreens that pass the broad-spectrum test of UVA protection relative to UVB protection will be labeled "Broad Spectrum," noting that those broad-spectrum formulations with an SPF of 15 or higher will be allowed to make claims of preventing skin cancer and early aging. Non-spectrum (those with inadequate UVA protection) and broad-spectrum sunscreens with an SPF between 2 and 14 can only make claims to help prevent sunburn.

Some more new sunscreen rules:

1. Manufacturers will not be able to label sunscreens as "waterproof" or "sweatproof," or call their products "sunblocks," because FDA indicates these claims overstate the products' effectiveness.

2. Sunscreen makers will not be allowed to say a product provides sun protection for more than two hours without reapplication.