Most people think of sunscreen use only during the summer months. However, successful sunscreen use is to apply a lot of sunscreen liberally, repeatedly, and often to the body when exposed to the sun’s rays regardless of the time off the year. Sunscreens are best applied 15 to 30 minutes before sun exposure to allow the active ingredients to dissolve into skin layers. Epidemiologic data indicates that a history of five episodes of sunburn per decade increases risk for melanoma (a type of skin cancer) by threefold.
There is much confusion regarding the SPF (sun protective factor) values. SPF is primarily an indication of UVB protection as this type of radiation causes more skin redness than UVA radiation. Damaging effects from UVB occur mostly in the summer as sunburn, but damage resulting in skin aging and skin cancer can occur throughout the year from UVA as well as UVB.
SPF of 15 blocks 93% of UVB radiation. SPF of 30 blocks 97% and an SPF of 50 blocks 98% of UVB radiation. Sunscreens can no longer be labeled witn an SPF greater than 50 and are now labeled as SPF50+. A “broad spectrum” sunscreen with protection from UVB and UVA is the most helpful and is recommended.
Use a “broad spectrum” product with SPF of 15 or 30. Apply to all exposed body parts. The amounts used should be 4 tablespoons/12 teaspoons, a shot glass full, or an amount to fill a child’s cupped hand. Sunscreen should be reapplied every 2 hours while outside and more when swimming. A large bottle of sunscreen will not last a whole family during the summer months. If it does, not enough is being applied. Sunscreen is available as liquid creams, sprays, gels, and sticks. Sprays are easy and convenient, but may cause too little sunscreen to be applied. Spray an adequate amount into hands and then apply. Gels may be good for the male chest or the scalp.