Sunscreen: The Burning Facts

Although the sun is necessary for life, too much sun exposure can lead to adverse health effects, including skin cancer. More than 1 million people in the United States are diagnosed with skin cancer each year, making it the most common form of cancer in the country, but it is largely preventable through a broad sun protection program. It is estimated that 90 percent of non-melanoma skin cancers and 65 percent of melanoma skin cancers are associated with exposure to ultraviolet (UV) radiation from the sun.

Are Sunscreens Effective?

By themselves, sunscreens might not be effective in pro­tecting you from the most dangerous forms of skin cancer. However, sunscreen use is an important part of your sun protection program. Used properly, certain sun­screens help protect human skin from some of the sun’s damaging UV radiation. But according to recent surveys, most people are confused about the proper use and effectiveness of sunscreens. The purpose of this article is to educate you about sunscreens and other important sun protection measures so that you can pro­tect yourself from the sun’s damaging rays.

How Does UV Radiation Affect My Skin? What Are the Risks?

UV radiation, a known carcinogen, can have a number of harmful effects on the skin. The two types of UV radiation that can affect the skin—UVA and UVB—have both been linked to skin cancer and a weakening of the immune system. They also contribute to premature aging of the skin and cataracts (a condition that impairs eyesight), and cause skin color changes.

UVA Rays

UVA rays, which are not absorbed by the ozone layer, penetrate deep into the skin and heavily contribute to premature aging. Up to 90 percent of the visible skin changes commonly attributed to aging are caused by sun exposure.

UVB Rays

These powerful rays, which are partially absorbed by the ozone layer, mostly affect the surface of the skin and are the primary cause of sunburn. Because of the thinning of the ozone layer, the effects of UVB radiation will pose an increased threat until the layer is restored in the latter half of the 21st century.

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How Do Sunscreens Work?

What Is the Sun Protection Factor (SPF)?

Sunscreens protect your skin by absorbing and/or reflecting UVA and UVB rays. The FDA requires that all sunscreens contain a Sun Protection Factor (SPF) label. The SPF reveals the relative amount of sunburn protection that a sunscreen can provide an average user (tested on skin types 1, 2, and 3) when correctly used.

Sunscreens with an SPF of at least 15 are recommended. You should be aware that an SPF of 30 is not twice as protective as an SPF of 15; rather, when properly used, an SPF of 15 protects the skin from 93 percent of UVB radiation, and an SPF 30 sunscreen provides 97 percent protection.

Although the SPF ratings found on sunscreen packages apply mainly to UVB rays, many sunscreen manufacturers include ingredients that protect the skin from some UVA rays as well. These “broad-spectrum” sunscreens are highly recommended.

What Are the Active Ingredients in Sunscreen?

Chemical Ingredients

Broad-spectrum sunscreens often contain a number of chemical ingredients that absorb UVA and UVB radia­tion. Many sunscreens contain UVA-absorbing avobenzone or a benzophenone (such as dioxybenzone, oxybenzone, or sulisobenzone), in addition to UVB-absorbing chemical ingredients (some of which also contribute to UVA protection). In rare cases, chemical ingredients cause skin reactions, including acne, burning, blisters, dryness, itching, rash, redness, stinging, swelling, and tightening of the skin. Consult a physician if these symptoms occur. These reactions are most com­monly associated with para-aminobenzoic acid (PABA)-based sunscreens and those containing benzophenones. Some sunscreens also contain alcohol, fra­grances, or preservatives, and should be avoided if you have skin allergies.

Physical Ingredients

The physical compounds titanium dioxide and zinc oxide reflect, scatter, and absorb both UVA and UVB rays. These ingredients, produced through chem­ical processes, do not typically cause allergic reactions. Using new technolo­gy, the particle sizes of zinc oxide and titanium dioxide have been reduced, making them more transparent without losing their ability to screen UV.

For the most up-to-date information on approved sunscreen ingredients, visit the FDA Web site at www.fda.gov.

How Can I Protect My Kids

Because children will be exposed to UV radiation for their whole lives, it is important to engrain sun safety practices at an early age. Many par­ents do not properly apply sunscreen on their children. Sunscreen should be applied and reapplied to all exposed areas. Blistering sun­ burns during childhood significantly increase the risk of developing skin cancer later in life.

Between 1973 and 2003, cutaneous melanoma increased by 81 percent. Incidence of pediatric melanoma is also on the rise—increasing almost 3 percent per year—making it just as important to teach children SunWise behavior. 

By teaching children about sun safety and encouraging them to take all of SunWise’s sun safety action steps, parents will ensure that their children understand the dangers associated with sun exposure and the ways to avoid them.

Babies

Keep babies out of direct sunlight. The American Academy of Pediatrics recommends using sunscreen on infants for small areas such as the face and back of hands where protection from clothing is inadequate.

SunWise Program

In response to the serious public health threat raised by overexposure to UV radiation, EPA is working with schools and communities across the nation through the SunWise Program. SunWise aims to teach children in elementary and middle school and their caregivers how to protect themselves from overexposure to UV. For more information, go to the SunWise Web site at www.epa.gov/sunwise.

Fail Safe Sunscreen?

Using sunscreen does not mean it is safe to spend more time in the sun, especially when the UV Index is high. Although a sunscreen with an SPF of 15 or higher offers protection from sunburn, it does not block all of the sun’s damaging rays. In fact, there is no evidence that sunscreens protect you from malignant melanoma, the deadliest form of skin cancer, even though sunburns have been linked with the development of melanoma. There is only limited evidence that sunscreens protect you from several other types of skin cancer.

To fully protect yourself, remember to seek shade, mini­mize peak hours of sun exposure, and wear protec­tive clothing in addition to applying sunscreen.

How Does the Outside Environment Influence Exposure?

The intensity of the sun’s UV rays reaching the Earth’s surface varies and should be considered when you plan out­door activities. The National Weather Service issues the UV Index, a daily forecast of UV intensity, for the United States.

You can obtain your local UV Index forecast daily from local weather sta­tions or newspapers. EPA’s Web site provides daily local UV forecasts for your ZIP Code or city and state at www.epa.gov/sunwise/uvindex.html. The higher the UV Index forecast, the stronger the sun will be and the greater the need to follow all the sun protection action steps. For days when the UV Index is unseasonably high for a particular loca­tion, EPA issues a UV Alert. You can sign up to receive an email-based UV Alert or daily UV Index forecast by going to https://enviroflash.epa.gov and entering your e-mail address and ZIP Code or city and state.

In general, UV strength is greatest from 10 a.m. to 4 p.m. during sunny summer days. Up to 80 percent of UV rays pass through clouds, however, meaning that sunburn is possible on cloudy days as well. UV exposure is greater at low latitudes (nearer to the equator) and/or high alti­tudes. Snow, water, and sand also increase sun exposure by reflecting incoming UV rays, making it especially impor­tant for skiers, boaters, and beachcombers to wear cloth­ing and hats and apply sunscreen.

How Do I Apply Sunscreen?

Use a broad-spectrum sunscreen with an SPF rating of 15 or higher. Apply sunscreen 20 minutes before going out into the sun (or as directed by the manufacturer) to give it time to absorb into your skin. Apply it generously and regularly—about 1 ounce every 2 hours—and more often if you are swimming or perspiring. A small tube containing between 3 and 5 ounces of sunscreen might only be enough for one person during a day at the beach. Do not forget about lips, ears, feet, hands, bald spots and the back of the neck. In addition, apply sunscreen to areas under bathing suit straps, necklaces, bracelets, and sunglasses. Keep sunscreen until the expiration date or for no more than 3 years, because the sunscreen ingredients might become less effective over time.

According to the FDA, “water resistant” sunscreens must maintain their SPF after 40 minutes of water immersion, while “very water resistant” sunscreens must maintain their SPF after 80 minutes of water immersion. Either type of water-resistant sunscreen must be reapplied regularly, as heavy perspiration, water, and towel drying remove the
sunscreen’s protective layer.

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About FDA

The FDA is responsible for protecting the public health by assuring the safety, efficacy, and security of human and veterinary drugs, biological products, medical devices, our nation’s food supply, cosmetics, and products that emit radiation. The FDA is also responsible for advancing the public health by helping to speed innovations that make medicines and foods more effective, safer, and more affordable; and helping the public get the accurate, science-based information they need to use medicines and foods to improve their health.