You can protect your skin from premature aging and skin cancers by using sun protective clothing and sunscreen on exposed areas. However, for a sunscreen to be effective, it must be used correctly. Here are some of the most common questions about sunscreens.
Which Sunscreens Offer Best Protection?
To make a specific personal choice, there are four criteria for selecting the best sunscreen. First, select a broad spectrum sunscreen that blocks both UVA and UVB. In particular, choose a sunscreen that includes a good level (around 4% to 5% or more) of zinc oxide (also called micronized zinc), or titanium dioxide, or Parsol 1789 (also called avobenzone) among the list of active ingredients. Second, choose a sunscreen with a SPF 30 rating or higher – this is the minimum level now recommended by most dermatologists across America. Third, determine the activity you will be doing for the day and apply a product that will meet the task, e.g. water activities mean you should use a waterproof sunscreen. Fourth, always choose a sunscreen that feels good on your skin – so you will be comfortable wearing it every day. The best way to be sure you like a sunscreen is to try a small sample on your skin. Once you have found a sunscreen or several that meet these four needs, use it regularly and properly and it will provide excellent sun protection.
What are the Main Ingredients in Sunscreen?
There are currently 16 active ingredients allowed for use in sunscreens by the Food and Drug Administration (FDA). These ingredients fall into two broad categories - absorbers (which create a chemical reaction to absorb UV) or reflectors (which are physical barriers that block or reflect UV rays away from the skin). Commonly used absorbers include homosalate, octisalate (also called octyl salicylate), octinoxate (also called octyl methoxycinnamate or OMC), octocrylene, oxybenzone, and avobenzone. The reflectors are titanium dioxide and zinc oxide. Most sunscreens contain some mixture of absorbers and/or reflectors and are available in creams, mousses, lotions and moisturizers. Hypo allergic and waterproof products are also available.
What is SPF?
SPF stands for Sun Protection Factor and measures the protection against UVB provided by a sunscreen. An SPF 15, when applied properly, protects you against 14 out of 15 parts of UVB or 93 percent UVB. An SPF 30 protects you against 29 out of 30 parts of UVB or 97 percent UVB.
Sunscreens do not work without proper application (see below), nor will they work for longer than 2 hours without reapplication.
What is Broad Spectrum?
Broad spectrum protects skin against both UVB and UVA. UVA is now considered as dangerous as UVB.
How should Sunscreen be Applied?
First, it should be applied 20 minutes before going outside to allow it time for it to penetrate or bind to the skin. Second, you need to use an adequate amount. If you under apply you are likely to get burned - this is probably the most common mistake made by sunscreen users. The recommended level is 2 mg sunscreen/square cm skin. For the average adult needing to cover themselves at the beach, this means using a shot glass full of sunscreen per application. Third, even if the label says "all day protection” you should reapply every two hours while outside until sunset. The term "very water resistant" means one must reapply every 90 minutes when swimming, "water resistant" means one must reapply every 40 minutes when swimming. Fourth, do not use old sunscreen. Check the expiration date and throw away old sunscreen.