Mayo Clinic Health Manager

Get free personalized health guidance for you and your family.

Get Started

Free

E-Newsletter

Subscribe to receive the latest updates on health topics. About our newsletters

  • Housecall
  • Alzheimer's caregiving
  • Living with cancer

continued:

Sunscreen: Answers to your burning questions

What reduces the effectiveness of sunscreen?

How much protection your sunscreen offers depends on many factors, including how likely your skin is to burn (your skin type), the amount and type of sunscreen used, how often the sunscreen is applied, and how intense the UV rays are.

In addition, many factors can make sunscreen less effective. These include:

  • High humidity
  • Sweating
  • Drying or rubbing your skin with a towel
  • Swimming, showers or other contact with water

What should you look for when buying sunscreen?

Not all sunscreens are the same. Be sure to:

  • Select a broad-spectrum sunscreen with an SPF of at least 15. Broad-spectrum products provide protection against both UVA and UVB radiation. Look on the ingredient labels for oxybenzone, sulisobenzone, avobenzone (Parsol 1789), ecamsule, titanium dioxide or zinc oxide.
  • Watch for added ingredients that may irritate your skin. Some sunscreens contain fragrances, preservatives and other ingredients that cause skin reactions in some people. If you have sensitive skin, look for sunscreen that doesn't contain potential allergens, such as fragrances or dyes, and is specifically designed for your type of skin.
  • Understand labels. Look for sunscreens labeled "water resistant," which offers some protection against washing off in water or when perspiring heavily. Sunscreens can no longer be labeled "waterproof" because all sunscreens wash off to some extent. Other terms that can no longer be used on sunscreen product labels include "sun block" (no product actually blocks all UV rays) and "all-day" (no sunscreen lasts all day).
  • Make sure any product you use actually contains sunscreen. Many tanning oils and lotions don't. Products that don't contain sunscreen are required by law to clearly indicate that on the label.

How much sunscreen is necessary, and how often should it be applied?

Most people use sunscreen too sparingly. A liberal application is 1 ounce (29 milliliters) — the amount in a shot glass — to cover all exposed parts of the body. If you have a 4-ounce (118-milliliter) bottle, you'll be using about one-fourth of it for one application. Be sure to rub the sunscreen in well.

To maximize protection, apply sunscreen liberally 30 minutes before going outdoors and reapply every two hours, or sooner as needed.

Is sunscreen enough to protect your skin?

Though it offers some protection, no sunscreen blocks out all of the UV rays. Therefore, sunscreen shouldn't replace other protective measures, such as limiting the time you spend in the sun and covering your skin. For the most complete sun protection, use all three of these methods:

  • Avoid the sun between 10 a.m. and 4 p.m. Because the sun's rays are strongest during these hours, try to schedule outdoor activities for other times of the day. Seek shade whenever possible. If you're unable to avoid being in the sun, limit the amount of time you're outdoors during these peak hours.
  • Cover up. Wear tightly woven clothing that covers your arms and legs and a broad-brimmed hat, which provides more protection than does a baseball cap or golf visor. Also, consider wearing clothing or outdoor gear specially designed to provide sun protection.
  • Use sunscreen frequently and liberally. Apply sunscreen liberally 30 minutes before going outdoors and reapply about every two hours. Use it even on cloudy or hazy days. UV rays can penetrate cloud cover.
Previous page
(2 of 2)
References
  1. Sunscreens/sunblocks. American Academy of Dermatology. http://www.aad.org/public/publications/pamphlets/sun_sunscreens.html. Accessed Jan. 20, 2009.
  2. The burning facts. Environmental Protection Agency. http://www.epa.gov/sunwise/doc/sunscreen.pdf. Accessed Jan. 20, 2009.
  3. Sunscreen drug products for over-the-counter human use: Final monograph. Food and Drug Administration. http://www.fda.gov/cder/fdama/fedreg/sunscreen.pdf. Accessed Jan. 20, 2009.
  4. Skin cancer: Questions and answers. Centers for Disease Control and Prevention. http://www.cdc.gov/cancer/skin/chooseyourcover/qanda.htm. Accessed Jan. 20, 2009.
  5. FDA approves a new over-the-counter sunscreen product. U.S. Food and Drug Administration. http://www.fda.gov/bbs/topics/NEWS/2006/NEW01417.html. Accessed Jan. 20, 2009.
  6. Parenting corner Q&A: Sun safety. American Academy of Pediatrics. http://www.aap.org/publiced/BR_SunSafety.htm. Accessed Jan. 21, 2009.
  7. Facts about sunscreen. American Academy of Dermatology. http://www.aad.org/media/background/factsheets/fact_sunscreen.htm. Accessed Jan. 21, 2009.

SN00044

March 27, 2009

© 1998-2009 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Reliable tools for healthier lives," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

Print Share Reprints

Text Size: smaller largerlarger