The sun produces two types of ultraviolet (UV) radiation, UVA and UVB. UVA radiation causes skin damage, premature aging, and skin reactions to medications, soaps, cosmetics, and other chemicals. UVB radiation causes sunburn. Both UVA and UVB radiation increase your risk of skin cancer. Most sunscreens protect against UVB radiation, but you should use a sunscreen with both UVA and UVB protection (broad-spectrum coverage). Products that protect against UVA include ingredients such as avobenzone, octocrylene, titanium dioxide, zinc oxide, and benzophenones such as oxybenzone. Ask your doctor or pharmacist if you have questions about selecting a product.
Sun Protection Factor (SPF) is a rating that tells how much protection a product provides against sunburn. The higher the number, the greater the protection. An SPF of at least 15 is recommended. Products with SPF 30 provide high protection against sunburn. The FDA states that products with SPF above 30 provide a benefit that is not much greater than SPF 30 products.
Water-resistant products provide protection for up to 40 minutes of water activity or sweating. Very water-resistant products protect for up to 80 minutes. Reapply sunscreen as often as necessary.
Remember that water, sand, and snow reflect the sun. You should protect yourself with sunscreen when in these surroundings. Apply sunscreen even on cloudy days because the sun's radiation is still present. In addition to sunscreen, wear protective clothing (such as hat, long sleeves/pants, sunglasses) when outdoors, and stay in the shade when possible. Avoid prolonged sun exposure, especially between 10 AM to 4 PM when the sun's radiation is strongest.