Sunscreen: True or False?

Dr. David TsaiPost by David Tsai, M.D. of Rex Primary Care of Holly Springs. Dr. Tsai is the medical director at Rex Primary Care of Holly Springs. He is a board certified family physician with a focus on primary care and sports medicine. To schedule an appointment with Dr. Tsai, please call (919) 552-8911.

Summer is finally here and the sun has been scorching. Are you a master of the tan or a raisin ready to happen? Read on to find out which of the following statements are true or false.

  1. SPF (sun protection factor) indicates protection from UVA and UVB.
    False! SPF is only a rating on a sunscreen’s ability to block ultraviolet B (UVB) rays. UVB causes sunburn and skin cancer. UVA causes skin aging/wrinkles and skin cancer.
  2. SPF 30 is 2x’s better than SPF 15.
    False! SPF 15 products block about 94% of UVB rays, and SPF 30 products block 97% of UVB rays, and an SPF 45 products block about 98% of rays.
  3. SPF indicates the level of protection for sunburn, wrinkles and skin cancer.
    False! Higher SPF ratings block slightly more UVB rays, but none offers 100% protection. The FDA states that “sunscreens labeled as both Broad Spectrum and SPF 15 (or higher), if used regularly, as directed, and in combination with other sun protection measures will help prevent sunburn, reduce the risk of skin cancer, and reduce the risk of early skin aging.”
  4. Broad spectrum sunscreen covers both UVA/UVB.
    True! The FDA allows the label “Broad Spectrum” if they protect against both UVA and UVB rays.
  5. Sunblock is better than sunscreen in UV light protection.
    False! Sunblock uses zinc oxide or titanium dioxide to reflect and scatter light off the skin surface. Sunscreen uses chemicals absorbed into your skin, to act as filters to absorb and deactivate UV rays. Both sunblock and sunscreen can be equally protective against UVA and UVB.
  6. Cloudy days, tanned and people with dark skin do not need sunscreen.
    False! People with dark skin can still burn and develop skin cancer. Likewise, tanning naturally or from a tanning bed does not impart protection. 80% of the sun’s rays still reach us on cloudy days, so protection is still needed.
  7. Waterproof labeling means the sunscreen won’t wash off.
    False! Products labeled “water-resistant” maintain their SPF level after 40 minutes of water exposure, while “waterproof” products do for 80 minutes. Avid outdoors types should consider choosing a biodegradable sun block rather than a chemical sunscreen as the latter has been implicated in damaging aquatic life, including bleaching and killing reef coral. and have such products.
  8. Apply sunscreen 15-30 minutes before exposure and every 2-3 hours during exposure.
    True! The American Academy of Dermatology advises sunscreen application to dry skin 15 minutes BEFORE going outdoors. Apply sunscreen every 2-3 hours; and after swimming or sweating heavily.
  9. Applying sunscreen on the face, arms, leg, back, and neck should be enough.
    False! Using one ounce, enough to fill a shot glass, is considered an adequate amount to cover the exposed areas of the body. Adjust the amount of sunscreen applied depending on your body size. Make sure to cover appropriately. Apply sunscreen to the back of the neck, ears, and the lips, which are commonly missed.
  10. Most people only apply 25-50 percent of the recommended amount of sunscreen.
    True! Most people do not apply enough sunscreen. So if you think you could be one of these people, next time you are getting ready for exposure, put on 50-75 percent more than you usually would.