This past weekend’s Wall Street Journal (June 30-31) included an article titled, “Burning Question: How Much Sunscreen” highlighting the fact that most of us do not apply enough product to receive the full protection benefit. The general rule of thumb for an adult is to apply a shot glass full of product rubbed into the skin to cover exposed areas. This amount should be adjusted according to body size. Recent research suggests the “teaspoon rule”: Use more than half a teaspoon for each arm, or the face and neck, and more than one teaspoon for each leg, the chest, and the back for a total of about 6 teaspoons, or 1 fluid ounce. (A shot glass holds 1.5 fluid ounces.)
What about SPF? The American Academy of Dermatology recommends using a broad-based sunscreen (blocks UVA and UVB rays) with a minimum SPF 30. It should ideally be applied at least 15-30 minutes before outdoor activity and reapplied every 2 hours and after water activity or heavy sweating. Sunscreens with SPF values above 50 were thought to be of no greater value but a recent study (paid for by Johnson & Johnson) found otherwise.
Keep in mind that sunscreen is one of the important measures for protecting yourself from overexposure to the sun. Others include wearing protective clothing, hats, sunglasses, and minimizing outdoor activities between the hours of 10 am and 3 pm.