Sunscreens have "active" ingredients that either absorb or block UVA and UVB rays. Currently there are seventeen FDA approved active sunscreen compounds but few offer UVA protection. Only AVOBENZONE, Encamsule, ZINC OXIDE and TITANIUM DIOXIDE offer significant UVA protection.

Most active ingredients do not block both UVA and UVB rays. The term broad spectrum connotes both UVA and UVB protection. Manufacturers often use a combination of actives to give broad spectrum protection.

Check to make sure your sunscreen gives true broad spectrum protection. Even if it says broad spectrum check the active ingredient label to make sure it has one of the true broad spectrum UVA actives in it. If it doesn't you are not getting broad spectrum protection. For the UVA/UVB protection Beyond Coastal actives offer see the "Active Ingredients" chart.

The Sun Protection Factor (SPF) system was developed to indicate protection from UVB rays. It DOES NOT indicate protection from UVA rays. The SPF number on your sunscreen indicates how much longer it will take you to burn than if you were not using it. If you burn in one minute without sunscreen, you would burn in 15 minutes with an SPF 15 sunscreen and 30 minutes with a SPF 30 sunscreen. This is highly dependent on many variables including: skin type, heat, humidity, how much sunscreen you used and your sun exposure over days. Use SPF numbers as guides not as hard and fast rules.

In general correct application and re-application of sunscreen is more important than relying on a high SPF number for your protection. If you are fair skinned, exercising in a hot humid environment, sweating profusely and have been doing so over a number of days your are better off applying the proper amount of SPF 15 3-4 times per day than applying an SPF 50 once.

Another way of looking at this is the percentage of UVB rays different SPFs block. SPF 10 "blocks" 90% of UVB rays, SPF 15 - 92%, SPF 30 - 97% and SPF 50 - 99%. If you apply an SPF 30 twice a day you will get more protection than applying an SPF 50 once especially if you are in and out of the water or sweating. There have been some recent tests that may refute this approach but at present it represents a "best practice."

At this time the FDA does not have a rating system for UVA protection. It has proposed a four star system that is under review. You can find more information on the final monograph here (U.S. Food and Drug Adminstration). The best way to determine the UVA protection of your sunscreen is to know what wave lengths the five UVA actives block and check to see if they are in your sunscreen. Normally a higher precentage of the ingredient means more protection at the specified wave lengths. Trade offs in ease of application or cost may accompany higher precentages of certain UVA actives.