Knowing the facts about sunscreen will help you stay safe in the sun. Keep your skin healthy with a few sun-protection-factor (SPF) tips.

Protecting skin from the damaging rays of the sun has always been a serious health issue. Today, with SPF up to 100 and new sunscreen products hitting the market every year, it's surprisingly difficult to know how much and what type of protection is best.

Don’t get burned by the very products meant to protect your skin. When it comes to sunscreen, it's important to separate fact from fiction.

Fact: More Is Better

More is better when you’re using sunscreen. Many people don't slather on enough sunscreen to get the full protective coverage needed. It’s best to use about one ounce of sunscreen for the body, which is enough to fill a shot glass. Reapply that same amount every two hours—more often if you're sweating a lot or in the water.

Spray-on sunscreen is a convenient option, but it can be difficult to get an even application. Make sure you spray a coat evenly across your skin, holding the bottle about four inches from your body. Be careful not to inhale spray sunscreen. When applying it to the head or neck, spray it into your hands first and then rub it onto the skin.

Fact: Sunscreen Isn’t Active Right Away

The skin needs a little time to absorb sunscreen before being exposed to sunlight. It’s best to apply sunscreen about 30 minutes before sun exposure.

Fact: There Are No FDA-Approved Sunburn Pills

Although researchers are trying to develop a true "sunburn pill," the ones available today are only supplements. They’re not federally approved medications. While they may seem like a safe alternative to sunscreen, there's no real evidence pills alone offer protection from the sun. Before taking any supplements, you should talk to your doctor, as they could interact with other medications.

Fiction: Higher SPF Means You Can Apply Less Product

Many people think sunscreen with a higher SPF means they can apply less and stay out in the sun longer. Unfortunately, that’s not the case, and SPF numbers can be deceiving. SPF indicates the amount of protection against UVB rays, but it isn’t a one-to-one measurement. For example, SPF 15 blocks about 93 percent of harmful UVB rays, SPF 30 blocks about 97 percent and SPF 50 blocks 98 percent. Thus, doubling the SPF doesn't necessarily provide that much more protection.

Fiction: Sunscreen Can Be Waterproof

Keep in mind, no sunscreens are "waterproof." If a product is labeled "water resistant," the FDA now requires manufacturers to designate how long the sunscreen is protective while swimming or sweating.

After swimming or sweating, dry off and immediately reapply sunscreen.

Fiction: All Sunscreens Are Basically the Same

Sunscreens are all designed to do the same thing, but that doesn’t mean products are interchangeable. Trying to figure out all the different numbers and terms on sunscreen labels can be challenging. Knowing what to look for makes it easier to find products that provide ample protection.

As we noted, the SPF numbers indicate the percentage of blocked UVB rays. The general consensus among experts is an SPF of 30 offers adequate protection for prolonged or intense sun exposure.

Look for products labeled "broad spectrum," which means the sunscreen protects against both UVA and UVB rays. UVA rays are responsible for photoaging, while UVB rays cause sunburns. Both can cause skin cancer.

There are also a number of active ingredients used to block UV rays. Sunscreens should contain two or more of the following:

• Aminobenzoic Acid – UVB

• Avobenzone – UVA1

• Cinoxate – UVB

• Ecamsule – UVA2

• Ensulizole – UVB

• Dioxybenzone – UVB, UVA2

• Homosalate – UVB

• Meradimate – UVA2

• Octinoxate – UVB

• Octisalate – UVB

• Octocrylene – UVB

• Oxybenzone – UVB/UVA2

• Padimate O – UVB

• Sulisobenzone – UVB, UVA2

• Titanium Dioxide – UVB, UVA2

• Trolamine Salicylate – UVB

• Zinc Oxide – UVB, UVA1, UVA2

Antioxidants may also be added to sunscreen to help support and protect the skin. Some antioxidants have shown to fight against free radicals. These oxidized molecules can cause cellular damage and age the skin prematurely.

Look for the Skin Cancer Foundation's Seal of Recommendation to quickly identify products that provide sufficient sun protection. The label “Active” means the sunscreen will protect against extended sun exposure and during recreational activities. “Daily Use” refers to products adequate for minimal sun exposure.

Other Ways to Protect Against UV Rays

In addition to sunscreen, doctors and dermatologists recommend everyone use other methods to protect themselves from the sun. Options include:

• Wearing clothes that cover the arms and legs

• Wearing clothing that has UPF (ultraviolet protection factor)

• Wearing wide-brimmed hats that protect the face, head and ears

• Wearing sunglasses that have 100 percent UV protection

• Staying out of the sun between 10 a.m. and 4 p.m.

Using sunscreen today means you're protecting yourself from skin cancer in the future. Simply knowing the best ways to apply your sunscreen can reduce this serious health risk. Next time you enjoy a day outdoors, remember to separate fact from the fiction.