Everything You Ever Wanted To Know About Sunscreen

The best way to avoid a sunburn is to stay out of the sun, but what’s the fun in that? Sunscreen is the next-best thing.

Or is it?

Social media is rife with misinformation about the safety, ingredients, regulation, and even the necessity of sunscreen, despite it being one of the most widely recommended products in medicine, according to Stanford University School of Medicine. Decades of uneven product labeling and testing standards have contributed to the confusion, according to the medical school.

Here’s everything you need to know about sunscreen to protect yourself from UVB rays, which cause sunburn and contribute to skin cancer, and UVA rays, which are associated with aging and wrinkles, and can also contribute to cancer.

What’s The Highest SPF You Can Buy?

SPF is an acronym for “sun protection factor,” a measure of how well sunscreen protects from the sun’s harmful ultraviolet rays.

SPF 100 sunscreen products are widely available. The higher the SPF rating, the longer the protection. Importantly, an SPF of 100 doesn’t provide 100 percent protection, but it is more effective than products with lower SPF ratings.

Most dermatologists agree it’s best to use a sunscreen with an SPF of at least 30, which blocks 97 percent of the sun’s rays. An SPF of 100 would only block between 1 percent and 2 percent more of the sun’s rays.

Despite myths to the contrary, the SPF does not affect how long a person is protected. Protection typically lasts two hours or less for all sunscreens, according to Mayo Clinic. That means it should be regularly reapplied.

When selecting a sunscreen, it’s best to get a broad-spectrum sunscreen that blocks the harmful UV rays, and also one that is water-resistant.

For sunscreen to work, it must be correctly applied, and that’s where many people fall short, according to Dr. Joyce Teng, a professor of pediatric dermatology at Stanford Medicine.

“It’s really important to use a good, thick layer of sunscreen,” Teng said. “If an active teen or adult has a 6- or 8-ounce bottle of sunscreen they’re using all summer, there’s no way they’re using enough. If you’re outside regularly, that bottle should last about two weeks.”

What Brands Are Best?

That’s a matter of preference, as long as the sunscreen contains the right ingredients, according to the University of California-Davis Health.

That means it should contain physical blockers, such as zinc oxide and titanium dioxide, or chemical blockers such as avovbenzone, oxybenzone and others). UC-Davis Health said the physical blockers, which are sometimes called mineral sunscreens, tend to provide broader coverage and are effective immediately after application because they work by reflecting the UV rays. Chemical blockers should be applied 20 minutes before sun exposure and work by absorbing UV rays.

Also, while the physical blockers tend to be thicker and can be difficult to rub in compared to chemical blockers, people with sensitive skin tolerate them better, UC-Davis Health noted.

Are Sunscreens With Chemicals Safe?

Importantly, while the avovbenzone and oxybenzone in chemical sun blockers have benzene rings in their chemical profiles, they are distinct compounds from benzene.

Benzene is a carcinogen naturally found in crude oil, gasoline and cigarette smoke that is known to cause cancer in humans. It is also used in the production of a wide range of industrial products, including chemicals, dyes, detergents, and some plastics.

Although benzene is not used in sunscreens, several companies have issued recalls in recent years after trace amounts were discovered in their sunscreens. The benzene wasn’t intentionally added, but likely formed when certain compounds used in spray propellants combined to form benzene, according to the Cleveland Clinic.

Concerns have also been raised about the use of sunscreens containing oxybenzonen, so that’s something to keep in mind when choosing a sunscreen.

The authors of a peer-reviewed study on sunscreen safety and efficacy don’t recommend using sunscreens that contain oxybenzonen because of their potential effect on the body’s neuroendocrine system, which controls many important functions through hormones, including growth, metabolism, reproduction, and even how a person handles stress.

Is It OK To Skip Sunscreen, Limit Exposure?

Limiting exposure to the sun when the UV index is high, from 10 a.m. to 4 p.m., is a good idea, but it’s not recommended as a substitute for sunscreen, according to Mayo Clinic.

“However, this doesn’t mean early mornings and late afternoons are without risk,” according to Mayo. “You need skin protection from sunrise to sunset.”

Is Sunscreen Good For Babies And Toddlers?

The American Academy of Dermatology recommends that parents avoid exposing babies younger than 6 months to the sun’s rays and keep them in the shade as much as possible. If shade isn’t an option, create it with an umbrella, canopy or hood on a stroller.

Parents are also encouraged to dress babies in lightweight clothing with long sleeves and pants, and a wide-brimmed hat and UV-filtering sunglasses.

The AAD doesn’t recommend using sunscreen on babies younger than 6 months, but if there’s no shade or a way to create, lightly apply an SPF 30 or higher mineral-based physical blocker containing zinc oxide and/or titanium dioxide as active ingredients. It should be reapplied every two hours, and washed off when the baby is back inside.

It’s safe to apply the same sunscreen on babies over 6 months and toddlers, but be sure to follow the instructions on the product label. It should be reapplied every two hours when the child is outside.

Is It OK To Skip Sunscreen On Cloudy Days?

Mayo says it is a common myth that people cannot get a sunburn or damage their skin when it’s cloudy, raining or during the winter.

Sunscreen is needed any time the sun is up, regardless of cloud cover or the season.

“Water, sand and snow can reflect the sun, which exposes your skin to indirect UV rays. No matter the weather or the season, applying sunscreen every day is a must,” according to Mayo.

Do People Who Tan Easily Need Sunscreen?

There’s no such thing as a safe tan, according to Mayo, which explained tanning is the body's response to UV damage and a sign that skin has been injured.

“Even getting just a ‘glow’ damages your skin’s DNA, and increases aging and your risk of skin cancers,” Mayo said. “A tan will not protect your skin from sunburn or other sun damage.”

Do People With Darker Skin Need Sunscreen?

It’s a dangerous myth that people of color don’t need sunscreen, according to research. For example, this study indicated mortality rates for people with skin cancers were higher for people of color, and UV exposure was the leading cause.

The authors concluded the increased rates of skin cancer among people of color are “due to lack of awareness, diagnosis at a more advanced stage and socioeconomic barriers hindering access to care.”

“Raising public health concerns for skin cancer prevention strategies for all people, regardless of ethnic background and socioeconomic status, is the key to timely diagnosis and treatment,” they said.

Is Wearing Makeup With SPF Enough?

Consider it an extra layer of protection for the face, but not a substitute for sunscreen, according to experts.

Mayo says it’s a good idea to apply sunscreen with an SPF of 30 before applying foundation, and also to the throat, back of the neck and other sun-sensitive areas.

Does Clothing Offer UV Protection?

It does, but it’s not a great substitute for sunscreen in the hot summer months. Darker, heavier fabrics with tiger weaves offer more protection than the lightweight, light-colored clothing of summer.

Many new fabrics offer both protection and breathability. Look for an ultraviolet protection factor, or UPF, of 50 or more.

“The more skin you cover, the better,” Mayo recommended. “Don’t forget to accessorize your outfit with a wide-brimmed hat and UV-filtering sunglasses.”

Choose sunglasses that have 100 percent UVA and UVB protection. Also, sunglasses with polarized lenses decrease glare from surfaces, but do nothing to protect the eyes from UV rays.

What About Getting Enough Vitamin D?

Vitamin D is a hormone that can be generated in the skin by ultraviolet light, but can also be ingested as a supplement or dietary choices.

Vitamin D deficiency can cause serious diseases, most involving bone health. In children, it can cause rickets, a condition where bones become soft and deformed. In adults, it can cause osteomalacia, which causes bone pain and muscle weakness. Vitamin D deficiency has also been linked to an increased risk of osteoporosis.

“By avoiding sunburn and wearing high-quality sunscreen, higher levels of vitamin D can be achieved while minimizing the risks associated with UV exposure,” according to the authors of this study. “When UV light is not abundant, vitamin D supplementation may also benefit health.”

Even well-applied sunscreens allow 2 percent to 3 percent of the sun’s UVB rays to reach the skin, and the body needs only a little to produce vitamin D. Rather than risk skin cancer, it’s better to seek vitamin D through a healthy diet or supplement, according to Mayo.

Fatty fish like salmon and tuna are rich in vitamin D, as are egg yolks and mushrooms. Products such as milk, yogurt and orange juice are often fortified with vitamin D.

Is Spray Sunscreen OK On A Plane?

Summer vacation checklists should include sunscreen, whether it’s purchased beforehand or after arrival at a travel destination.

It’s fine to take spray sunscreen in carry-on baggage as long as it adheres to the rules applied to other liquids, gels and aerosols, according to the Transportation Security Administration.

That means the container must be no more than 3.4 ounces and can fit into a small, quart-sized, clear, resealable bag.

If it’s in a larger container, it must be packed in checked baggage.

If Traveling Abroad, Buy There

People who are traveling abroad may want to buy sunscreen once they reach their destinations, according to Stanford Medicine professor of dermatology Dr. Susan Swetter.

“Sunscreen technology abroad has resulted in the development of 30 UV radiation (UVR) filters, many that extend to the ‘far UVA’ wavelength, compared with only 17 FDA-approved UVR filters in the U.S., despite similar safety standards,” Sweeter said. “The best sunscreens abroad contain Tinosorb, Mexoryl or Uvinul — none of which are currently FDA-approved.”

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