Sun Protection Tips

Reviewed by: HU Medical Review Board | Last reviewed: May 2017.

Skin cancer is common but often preventable. By protecting yourself from the sun, you can reduce your risk of skin cancer considerably.

You can protect yourself from harmful ultraviolet (UV) rays by:1,2

    • Using sunscreen
    • Seeking shade
    • Wearing protective clothing
    • Avoiding indoor tanning beds

Even at low levels, UV radiation damages all types of skin.3 For this reason, sun protection is recommended for everyone, regardless of skin tone.

Tips for choosing and using sunscreen

At one time, sunscreen was something people used only occasionally for long days at the beach. Now, major organizations recommend using sunscreen any day you will be outside, even if it is cloudy or cool.2,4,5 Daily sunscreen use reduced melanomas by approximately 50% in one long-term study of more than 1,600 people.6 Sunscreen alone is not enough, though. Experts recommend using it together with other types of sun protection.2

Choose sunscreen labeled “broad spectrum.” Ultraviolet radiation includes UVA and UVB rays. UVB rays cause sunburn, and all sunscreens protect against UVB. However, both UVA and UVB contribute to skin cancer. Sunscreens labeled “broad spectrum” protect against UVA and UVB rays.2

Choose a sunscreen with an SPF of 15 or higher. SPF stands for sun protection factor. These numbers indicate the effectiveness of blocking UVB rays. The higher the number, the greater the protection. The Centers for Disease Control and Prevention (CDC) recommends a minimum of SPF 15.3 SPF 15 sunscreen blocks 93% of UVB rays.7 The American Academy of Dermatology (AAD) suggests using sunscreen with at least SPF 30, which blocks 97% of UVB rays.5,7

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Reapply every 2 hours—or sooner. Sunscreen is effective for about 2 hours, so reapply throughout the day! This is true no matter what SPF you choose: SPF 30 does not last longer than SPF 15. You may need to reapply sooner if you are sweating, swimming, or toweling off.2,4

Pay attention to water resistance. No sunscreen is waterproof. Sunscreen may be labeled as water resistant for 40 or 80 minutes. This is the amount of time the sunscreen provides protection while swimming or sweating.2

Use a lot. It generally takes at least 1 ounce (one shot glass) of sunscreen to fully cover an average sized adult or child.2

What is the difference between physical and chemical sunscreen?

Sunscreens can be classified as physical or chemical, depending on how their active ingredients work.8 Chemical sunscreens have ingredients that absorb UVA and UVB rays. Examples of these chemicals are avobenzone or benzophenones (such as dioxybenzone, oxybenzone, sulisobenzone). Physical suncreens have ingredients that reflect or scatter UV rays. The active ingredients in physical sunscreens are titanium dioxide and zinc oxide.

Is sunscreen safe?

Use of sunscreen is recommended by major organizations such as the CDC, the US Food and Drug Administration (FDA), and the AAD.2,4,5 The AAD states that that “preventing skin cancer and sunburn outweigh any unproven claims of toxicity or human health hazard from ingredients in sunscreens.”9

The Food and Drug Administration regulates sunscreens and the active ingredients described above.2,8 It is currently developing a new process for studying how safe and effective the active ingredients in sunscreen are.10 The FDA is also studying the risk of accidental inhalation of spray sunscreens.9

When to seek shade

The sun is most intense between 10 am and 2 pm. Sunscreen alone is not enough to protect your skin from harmful UV rays. At midday, find some shade under a tree, umbrella, or inside. Remember that water, snow, and sand reflect the sun’s rays. UV exposure is more intense in these conditions.11

Your shadow can tell you how much UV exposure you are getting. If your shadow is taller than you, your UV exposure is lower. Typically, this happens in the early morning and late afternoon. If your shadow is shorter than you—as it is around midday—your UV exposure is greater.12

UV Index Levels

Low (<2)
Moderate (3-5)
High (6-7)
Very High (8-10)
Extreme (11+)

Source: United States Environmental Protection Agency

Wearing protective clothing

Examples of clothing that protects your skin from the sun’s rays are:4

      • Long-sleeved shirts
      • Long pants and skirts
      • Wide-brimmed hat
      • Sunglasses that block UVA and UVB

Darker colors and fabrics with a tight weave offer the most sun protection.4 In general, synthetic and shiny fabrics (polyester, lycra, and nylon) are more protective than cotton or linen.11 Wet clothing is less protective than dry clothing.4

Some clothes are labeled with a UPF or UV Protective Factor.11 The UPF indicates how well that fabric protects against the sun. Higher ratings indicate more sun protection.

Is indoor tanning a safe alternative to outdoor sun?

No, indoor tanning is not a safe alternative to outdoor sun. The risk of skin cancer is higher for people who use tanning beds than for people who do not.13 Indoor tanning causes an estimated 419,000 cases of skin cancer each year.14 The AAD opposes indoor tanning and has called for a ban on indoor tanning equipment.1