AARP Smart Guide to Sun Protection

Understand the difference between UVA and UVB rays 

The sun produces three types of ultraviolet (UV) rays: UVA, UVB and UVC rays. UVC rays are blocked by the hemisphere, so we don’t have to worry about those. UVA rays are the most powerful and are present during all daylight hours. These rays reach the epidermis of our skin (top layer) and into the dermis (the middle layer of our skin), and cause wrinkles and fine lines. UVB rays cause damage to the epidermis and are the chief culprit behind skin reddening and sunburn, and over time can lead to skin cancer. Too much exposure to UVA and UVB rays can lead to skin cancer, which is why it’s imperative to use a sunscreen that is labeled broad-spectrum — meaning that it blocks both UVA and UVB rays. Most active ingredients in sunscreen shield against UVB, but far fewer have UVA coverage, so look at the bottle carefully. 

Decipher SPF ratings 

SPF stands for “sun protection factor.” It refers to how much solar energy (UV radiation) it takes to result in a sunburn on your skin with sunscreen applied, relative to skin with no sunscreen applied. For example, SPF 15 blocks about 94 percent of rays, SPF 30 blocks 97 percent, and SPF 50 blocks about 98 percent. As a base, use at least SPF 30, which is what most dermatologists recommend. No sunscreen can offer 100 percent protection, but higher SPF numbers allow you to be out in the sun longer. 

Choose between mineral or chemical sunscreen

There are two main types of sunscreen — mineral-based (physical) and chemical-based. Both shield your skin from the harmful effects of the sun’s UV rays, but they work in different ways.

Mineral sunscreens sit on the surface of the skin and physically prevent UV rays from penetrating. They contain ingredients such as zinc oxide and titanium dioxide, and tend to be thicker than their chemical sunscreen counterparts. Mineral sunscreens are also less irritating for sensitive skin. Chemical sunscreens work by absorbing UV rays. They use ingredients such as oxybenzone, octinoxate, avobenzone and octisalate to attract UV rays like sponges and then turn them into heat that’s released from the skin. Dermatologist Geeta Yadav, M.D., of Facet Dermatology in Toronto, Canada, says they “work by creating a chemical reaction that absorbs energy from the sun [to] protect the skin.” There are several benefits to chemical sunscreens: They go on transparent, work for a range of skin tones, are more lightweight and tend to be more breathable. The downside to chemical sunscreens is that they can cause skin irritation and inflammation for some, especially those with sensitive skin. In this case, a mineral (physical) sunscreen may be best. 

Reapply SPF after two hours 

SPF only provides protection for roughly two hours when outdoors. This means that reapplication is just as necessary as — and perhaps more crucial than — your initial application. And this is the case

whether you’re using a chemical or mineral SPF. According to Karen Fernandez, a lead aesthetician at the SkinSpirit spa in California, mineral SPF relies on the physical barrier of zinc oxide and titanium dioxide to provide coverage. But after two-plus hours, it’s likely that “the product has been wiped off or is no longer evenly applied,” she says, noting that sweat — even the slightest amount — can also diminish a formula’s efficacy. It’s slightly different when it comes to chemical sunscreens, but the timing remains the same. “With a chemical sunscreen, the [active ingredients] have literally been used up after two hours,” Fernandez adds. So, according to the American Academy of Dermatology (AAD), the rule of thumb is to reapply SPF every two hours when you’re outside as well as after swimming or sweating. 

Rely on water-resistant formulas

If you know you’ll be spending time in or around water (or expect to sweat), always choose a water-resistant sunscreen. This is not to be confused with “waterproof.” You should always still reapply sunscreen every two hours, or more often, if you're swimming or sweating. Still, the benefit of water-resistant sunscreens is that they’re designed to keep your skin protected even while wet. “With physical SPF, the active ingredients will be the same as non-water-resistant versions, but the base will be different. It will be much thicker and oil-dense, which takes longer to dissolve in water,” Fernandez says. 

Choose based on skin type

If your skin is on the drier side, look for creamy textures that’ll nourish the skin as it protects. Yadav recommends hydrating ingredients that help quench dryness (like hyaluronic acid), as well as ceramides, which prevent moisture loss, and moisturizing emollients like jojoba oil, shea butter and squalane. If you have oily skin, avoid formulas that contain heavy oils and plant butters (like coconut oil, shea butter or cocoa butter), and stick with a mineral (physical) sunscreen, which is less likely to irritate. If you have sensitive skin, Yadav recommends formulas that contain soothing ingredients to help quell any existing irritation or redness, such as aloe, chamomile, green tea and niacinamide.

Choose based on skin tone

The idea that only lighter skin tones are more susceptible to UV damage is not only inaccurate, but it’s also dangerous and can lead those with melanated skin and darker complexions to believe that they do not need to protect their skin. The myth comes from an estimation that those with a darker complexion have a natural SPF of 13.4, whereas those with lighter skin have a natural SPF of about 3.4. This may lead many to skip sun protection — which can lead to a higher rate of death from skin cancer for Black people, due to a delay in detection or presentation. “While it’s true that people with fair skin tones are more susceptible to skin cancer because they have less melanin in their skin, that doesn’t mean those with deeper complexions are not at risk,” Yadav says. Though it’s less common, darker complexions are still at risk of developing melanoma, as well as nonmelanoma, skin cancer. 

Apply the right amount 

Most adults need about an ounce of sunscreen — enough to fill a shot glass — to fully cover their entire body, according to the American Academy of Dermatology (AAD). As for your face and front of the neck, Jamal says you’ll need about a quarter-teaspoon for maximum coverage. It’s important to note that it’s the incidental, short, unprotected exposures to the sun that will cause serious damage over time. There doesn’t need to be a burn in order for damage and the breakdown of healthy cells to occur, Fernandez adds. What this means for you: It’s crucial to wear the right level of protection, apply (and reapply) the correct amount of product, and always look for broad-spectrum products.

Protect your skin year-round

Apply sunscreen every day. There is no correlation between UV levels and temperature, so even in cooler weather, apply SPF sunscreen. Just like sand or water at the beach or pool reflects the UV rays, snow does so as well, increasing your sun exposure. 

Don’t forget often-missed spots

Fernandez says that the ears are a common area of your body that gets a ton of sun exposure. But because your ears contain fewer nerve endings, they won’t always alert you when a burn is happening — so it’s important to apply sunscreen heavily to this area. And while you’re putting sunscreen on your ears, dab some along your hairline and part as well, unless you’re wearing a hat. Don’t forget to apply SPF lip balm, too. Finally, your hands receive constant sun exposure and may not feel the burn or heat as the damage is occurring, Fernandez warns. Be sure to always add as needed to the tops of your hands.

When to apply

“SPF should always be the very last step of a skin care routine [but before makeup],” Yadav says. “It acts like a shield, protecting everything underneath. Also, if you were to apply it first, the subsequent application of your other products could cause the SPF to move around on your skin, rendering it less effective. Generally, I recommend people apply skin care from thinnest to thickest — and sunscreen is usually on the thicker end of the daily products most people use.”

Do the math right

Layering your sunscreens is not additive, and “your level of protection will be equivalent to the highest SPF of the products being applied,” Jamal says. This means that if you’re wearing a moisturizer with SPF 20, a sunscreen with SPF 30 and a foundation with SPF 20, your level of protection is 30 (not 70). That being said, Jamal notes that layering

multiple products does make it more likely that you are applying the correct amount of sunscreen (since most people tend to under-apply).

Incorporate SPF-makeup hybrids

Incorporating SPF-makeup hybrids into your beauty routine can offer additional layers of protection. It’s important to note, however, that most makeup products that contain SPF won’t offer adequate protection, because not enough product is applied by the user. Naana Boakye, M.D., a dermatologist at Bergen Dermatology in New Jersey, says that we need 2 milligrams of sunscreen per square centimeter of skin. This means you’d have to use layers upon layers of makeup to ensure sufficient protection, which the average person wouldn’t normally wear. So, in order to ensure maximum protection, you shouldn’t rely only on SPF-infused makeup products as your sole source of protection — rather, always apply a traditional SPF and think of any SPF-infused makeup product as the cherry on top.

Skip the sunscreen sprays

Although many think of sunscreen sprays as being extra convenient, many dermatologists recommend avoiding them due to a risk of lung irritation. Additionally, it can be difficult to make sure you’re getting enough coverage. Plus, current U.S Food & Drug Administration (FDA) regulations on testing and standardization do not apply to spray sunscreens. If you do use a spray, hold your breath, never spray near your face and always apply outdoors. Rub it in by hand to ensure an even application — your skin should be glistening. And you’ll still need to reapply every two hours. 

Shake the bottle well

If you’re using a mineral sunscreen, you may notice it has a tendency to separate or settle to the bottom. That’s why the directions on many recommend shaking the bottle before applying.

“All ingredients have different molecular weights and sizes, so you may need to give a little shake to incorporate all the ingredients and to make sure they are distributed properly,” Fernandez says. “All of the molecules work together, so full protection can only come from complete application.”

Be aware of expiration dates

Melissa Urban explains that your sunscreen will oftentimes have two date markers. One is the period-after-opening symbol that reflects how long the product is good for after you open it. This symbol looks like a container with its lid off, along with a number and an M next to it. For instance, if a product says “12M,” this means that once opened, the formula is good for 12 months. The second date marker you’ll often see is the product’s expiration date. Most sunscreens have a printed expiration date on the bottle itself or on the crimped part of the tube.

“Once this date has passed, the product may no longer produce effects that are true to its label, which is extremely important when we’re talking about sunscreen,” Urban warns. “If you’re applying an SPF 50 and it’s past its expiration date, this product is no longer producing SPF 50 protection.” Jamal says that the FDA requires that all sunscreens retain potency for three years. “If there is no expiration date, discard three years after the purchase date,” she says. Though, always take into account the product’s consistency, smell and color change, regardless of the expiration date, and discard if something seems off, Urban notes.

Stay out of the heat

Fernandez says it’s not just sun exposure that can trigger your melanocytes to hyperproduce and cause sun damage or discoloration. Heat and other stimulation can be factors as well.

“That's why it's important to keep your skin cool during the day, to avoid those triggers from causing more pigmentation,” says Fernandez, who rates mineral (physical) SPF sunscreens superior to chemical sunscreens, due to their ability to keep the skin protected and cool.

Research drug interactions

Many common medications can make your skin more sensitive to sunlight or increase your chances of heat-related illness. That’s because they contain ingredients that may cause photosensitivity, according to

the FDA. There are two types of photosensitivity reactions: photoallergy, an allergic reaction, and phototoxicity, an irritation of the skin. Both types occur after exposure to UV light. Drugs that may increase sun sensitivity include antifungals, antihistamines, antidepressants, antibiotics, cholesterol-lowering drugs, estrogen and oral contraceptives. Additionally, antidepressants, antihistamines, blood pressure medications and others may increase heat sensitivity. Not everyone will experience sun or heat sensitivity. View the FDA’s list and consult with your health care professional or pharmacist. 

Avoid peak hours

The U.S. Environmental Protection Agency says the sun’s peak hours are between 10 a.m. and 4 p.m., which is when UV rays are the strongest. Save your daily walks and other outdoor activities for before or after these peak hours. To understand when the UV rays will be the highest, no matter what time of year it is, check your weather app or weather website for the UV index. It gauges unprotected risk from the sun on a scale of 1 to 11, with midday hours typically scoring a higher potential for damage. 

Consider installing a UVA protective film

If you’ve ever driven for long periods of time, you may have noticed your left arm got more sun than your right, even with the window rolled up. That’s because most glass doesn’t stop UV rays. In 2012, The New England Journal of Medicine published a photo of a 69-year-old truck driver who had extensive sun damage to the left side of his face, after being behind the wheel for 28 years. Nearly three decades of having the sun shine through his driver-side window resulted in unilateral dermatoheliosis, or photodamaged skin. The stark visual difference is a reminder that untreated glass can be penetrated by UVA rays. UVA-protective film is available for your car, home or office. It is typically effective for about a decade and can block up to 99.9 percent of UV radiation.

Cloudy days can do damage, too

We usually only think about sun protection when it's sunny outside — but you can still get a sunburn when it's overcast and gray. In fact, clouds can sometimes increase, rather than reduce, levels of ultraviolet radiation. This phenomenon, called the “broken-cloud effect,”
can result in higher UV levels than on a perfectly cloudless day. While scientists don’t know why this happens, one theory is that UV rays “bounce” off clouds and then are redirected, creating a combination of refraction and reflecting that could result in significantly greater UV strength at ground level. So even if you aren’t seeing the sunlight hitting your skin, UV rays are still reaching it — which is why you should be applying sunscreen every day. 

Get your vitamin D levels checked 

Your body makes vitamin D when sunlight (UVB rays) hits the skin. Getting as little as 10 to 15 minutes in the direct sun a few days a week can provide us with most of the vitamin D our bodies need to maintain healthy bones, muscles and immune systems, while also protecting us from cognitive decline. If you’re not getting enough sunshine, talk to your doctor about testing your vitamin D levels to find out if you should take a supplement. Dietary guidelines call for 600 international units (IUs) daily of vitamin D, and that’s a good place to start. 

Consider your entire sun-protection strategy 

Sunscreen is just one part of blocking the sun’s harmful rays. It’s also important to seek shade, cover up with clothing and wear wide-brimmed hats as needed. Driving gloves will help to protect your hands from the sun’s harmful rays while you’re on the road. And there are sun blankets made of UV-protective material that you can wear while spending time outdoors.

Wear dark colors

It may seem counterintuitive, especially on hot days, but dark blue, black and dark red are the best colors of clothing for sun protection. That’s because darker colors absorb the UV rays before they can hit your skin. Synthetic fibers, like polyester or nylon, work better than cotton or rayon. Thicker materials with a tighter weave will provide more protection than loose-weave or lightweight fabric. You can also wear clothing with SPF protection. Look for an ultraviolet protection factor (UPF) of at least 30. 

Protect your eyes

Excessive UV exposure can lead to cataracts. The American Optometric Association recommends wraparound sunglasses that boast a 99 to 100 percent UVA and UVB protection. Wearing a hat also protects your face, scalp and neck — three areas that see the most sun damage. 

Avoid tanning beds or sunlamps

Both tanning beds and sunlamps give off UV radiation, and they can cause skin cancer, skin burns and premature skin aging, as well as

short-term and long-term eye damage. Avoiding both will reduce your skin cancer risk. Another light you may be forgetting? The UV light you use to set your nails can cause the same kind of skin cancers that tanning beds and sunlamps do. So when using one, apply at least a 30 SPF broad-spectrum water-resistant sunscreen to your hands or wear gloves with the tips cut off. 

Stop smoking

About 90 percent of nonmelanoma skin cancers and 86 percent of melanomas have been linked to exposure to UV radiation from sunlight, according to the Skin Cancer Foundation. But not all skin cancer is caused by the sun. Current smoking and heavy smoking were associated with a higher risk of squamous cell carcinoma (SCC), which is the second-most common skin cancer. 

Supplements that may help

Could popping a supplement help stave off nonmelanoma skin cancers? Nonmelanoma refers to the types of cancer that occur in the skin that are not melanoma, such as basal cell carcinoma and squamous cell carcinoma. While more research is needed, a small study published in American Health & Drug Benefits showed that nicotinamide, a vitamin B3 supplement, has been found to help lower the rate of new squamous-cell and basal-cell skin cancers by 23 percent for high-risk individuals. It also lowered the risk of precancerous actinic keratosis. Other supplements and vitamins that help are selenium (Brazil nuts are a great source); vitamins C, E and A; zinc; beta-carotene; omega-3 fatty acids; lycopene (tomatoes, watermelon, grapefruit); and polyphenols (found in many foods such as tea, coffee, apples, onions, dark chocolate and red cabbage).