Summit Medical Group of Oak Ridge

Sunscreen Q & A-by Dr. Susan Taylor

Monday, May 11th, 2015

As spring arrives and we venture outdoors, it’s important to protect our skin from the sun’s damaging rays. Sunscreens, when properly applied, can provide protection from sun damage and minimize your risk of skin cancers. Here are some common questions:
When is the best time to put on sunscreen?
Sunscreen should be applied 20-30 minutes before sun exposure. This allows the lotion to be well absorbed by your skin. You should re-apply every 2 hours, especially if swimming or sweating heavily.
What type of sunscreen is best?
You will want a product protecting against both UVA and UVB rays. Most experts recommend an SPF of 15-30. There is likely no added benefit to having an SPF over 50.
What if I have sensitive skin?
If your skin is sensitive, you will want to avoid spray-on sun blockers. Sunscreen containing Titanium Dioxide or Zinc Oxide will deflect the sun’s rays and work well for sensitive skin. Also hats and clothing are good protection.
How long can I swim with sunscreen on?
40-80 minutes with a waterproof or water-resistant sunscreen.
Can sunscreen expire?
Sunscreens are usually effective for 3 years, but older ones should be discarded.
How effective are combinations of insect repellent and sunscreen?
For brief exposure, the 2-in-1 products would be safe and effective. However, this product should not be applied every 2 hours, as you would be over-applying the insect repellant. For longer exposure, it’s safer to use these products separately.