Don't Get Burned: What You Need to Know About Sunscreen

Most of us know that sunscreen is a necessity for those long days working in the garden or lounging by the pool. But there's still plenty of confusion: What SPF is best? How much is enough? Do cheap sunscreens protect as well as pricey ones? We have the answers. Here’s what to know the next time you grab a tube of sunscreen from the store shelves.

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Sunscreens labeled "broad spectrum" protect skin against UVA and UVB rays, which are different. While UVB rays are the primary cause of sunburn, UVA rays are responsible for premature aging effects, including wrinkles and age spots, and can increase the risk of developing certain types of cancer. It's crucial that your sunscreen offers protection for both, experts say.

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SPF stands for sun protection factor. Sunscreens with higher SPF ratings block a higher percentage of the sun's rays. According to the Skin Cancer Foundation, an SPF 15 sunscreen blocks about 93% of the harmful UVB rays responsible for burning skin. SPF 30 sunscreen filters out about 97%, while SPF 50 boasts a slightly higher rate of 98%.

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Once you get above SPF 50, there's only a very small bump in UVB protection, the SCF cautions. High SPFs can also give users a false sense of security, leading them to stay out in the sun all day, ignoring opportunities to cover skin or waiting longer between reapplication. The sweet spot, experts say? Between SPF 30 and 50.

The most common type of sunscreen, chemical-based sunscreens, contains ingredients that actually absorb the sun's rays and convert them into heat energy, according to the SCF. Some of the active ingredients include oxybenzone, which absorbs UVA and UVB, as well as a UVB absorber called para-aminobenzoic acid, or PABA. Oxybenzone in particular has stirred controversy because research on lab mice has showed it could be a hormone disruptor, but experts emphasize that there's no evidence of the same in humans.

Physical sunscreens use minerals that reflect the sun's rays. They generally rely on ingredients such as zinc oxide and titanium dioxide, and are typically preferred by buyers wary about chemical sunscreens. If sun protection is your bottom line, take note: Consumer Reports' tests suggest that physical sunscreens are generally less effective than chemical sunscreens.

We know: Sunscreen can get expensive. But this is no time to be stingy. The SCF cautions that most adults need to use at least an ounce — that's about as much as it would take to fill a shot glass — to adequately cover exposed areas of the face and body. Unfortunately, that means a standard-size bottle won't last that long with proper usage.

Once you've slathered your face, neck, arms and legs, you may think you're done. But be careful: It's easy to forget spots such as your ears, eyelids, lips, feet, and scalp, according to the Cleveland Clinic. Lip balm containing SPF can keep lips protected, and there are also special non-greasy formulas for the scalp and face.

It's generally recommended to reapply sunscreen about every two hours, and that's if you stay dry. If you go swimming or sweat a lot, you'll need to reapply more frequently. For more specific guidelines, check the back of the bottle.

UVA rays that can penetrate skin deeper than UVB rays (which do vary according to season and cloud cover) are always around, no matter the weather, experts tell Reader's Digest. Those same UVA rays can still boost your risk of skin cancer, as well as make your skin look older faster.

Don't wait until you get to the beach to slap on that sunscreen. The AAD cautions that it takes about 15 minutes for your skin to absorb chemical sunscreens and offer full protection. If you can't remember to apply sunscreen before heading outside, consider a physical sunscreen that offers immediate protection once it's on.

Darker skin has more melanin that naturally protects against the sun, but it's not enough to forgo sunscreen, experts say. Not only does the SCF warn that everyone can get skin cancer, it's actually deadlier for African Americans than any other group, according to a study by the SCF.

One persistent myth about sunscreen? That you won't get enough vitamin D if you use it. But the research shows that this simply isn't true. According to the SCF, some UVB rays will still reach your skin even with perfect sunscreen use. Further, it actually takes very little sun exposure to produce all the vitamin D your body needs. It's also easy to get vitamin D from food and dietary supplements.

All sunscreens are supposed to retain their original strength for three years, according to the AAD. But you should still throw out any sunscreen with an expiration date that has passed. If you buy a bottle that doesn't have an expiration date, write when you bought it on the tube.

Cool, dry places are best for long-term sunscreen storage. It might be convenient to keep a tube of sunscreen in your car trunk, but the heat can cause it to break down. If you'll be in the sun all day, the Food and Drug Administration recommends wrapping the sunscreen in a towel, putting it in a shady spot or even tossing it in a cooler.

If you see a bottle of sunscreen that says it's "waterproof," it's actually running afoul of an FDA ban on the term put into place on the grounds that it overstates sunscreens' effectiveness in the water. Instead, sunscreens that remain effective while the wearer is swimming or sweating are labeled "water resistant" and must indicate how long the water resistance lasts (40 minutes or 80 minutes).

You might think that tube of kids' sunscreen is somehow safer. But the FDA doesn't distinguish between the two or require a different formulation, according to Consumer Reports. If you're simply concerned about potential skin irritation, any sensitive-skin formulation should work. If the idea of chemical sunscreen is off-putting, then go for a physical sunscreen. But in either case, the active ingredients will most likely be the same.

If you have a very young child under 6 months, experts still say sunscreen is a no-go. Instead, they should be kept out of direct sunlight, especially during peak hours between 10 a.m. and 2 p.m., the Mayo Clinic cautions. Use protective clothing such as sun hats, and make use of those stroller sun shades.

Spray sunscreens are definitely convenient for people who want quick protection without the mess of slathering on a lotion. But the effects of accidental inhalation are still under study, and the AAD warns that the nearly invisible nature of sprays makes them easy to under apply. They're also dangerous to use near open flame, even after application.

Sunscreens range in price from $5 or $6 to well over $100 for boutique beauty creams. At the low end of that spectrum are popular brands such as Banana Boat, Coppertone, and Hawaiian Tropic, as well as store brands. But cheap formulas often do surprisingly well in lab testing, earning the respect of both experts and consumers.

Your closet is already full of clothes that block many of the sun's harmful rays. According to the SCF, tightly woven, dense fibers offer greater protection, as do synthetic fabrics such as polyester. Darker colors absorb UV rays better than lighter ones. You can also look for special sun-protective clothing, which will have a label stating UPF, or ultraviolet protection factor.

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