5 facts about sunscreen you probably didn't know

No one likes to hear it, but when it comes to sun safety, there's a good chance you're doing it wrong.

Nearly 5 million Americans are treated for skin cancer each year, making it the most common form of cancer by far, according to the American Cancer Society (ACS). Your skin is the largest organ of the body and the most subjected to the harsh ultraviolet (UV) rays of the sun, which are known to cause cancer, yet most of the damage is preventable with proper sunscreen use.

Cultivating facts from the ACS, U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and the Skin Cancer Foundation (SCF), we've come up with a list of things we think you should be aware of when using sunscreen.

1. Not all sunscreens protect you from the sun.

Many sunscreens only protect you from the sun's UVB rays, and not UVA rays. UVB rays penetrate the top layer of skin and cause burns, while UVA rays contribute to wrinkles, premature aging, and can damage your DNA. The ACS says that both types of UV radiation can cause skin cancer, and also warns that tanning beds are known to give off large amount of UVA rays.

According to Consumer Reports, of 58 sunscreens tested in 2017, 20 had less than half their labeled SPF.

The ASC, FDA and CDC all recommend to regularly to use SPF 15 or higher with the words "broad spectrum" on the label, which protects against UVB and UVA rays. According to the CDC, studies have shown the find that less than 15 percent of men use sunscreen regularly on any exposed part of their body when outside for more than an hour and "nearly 40 percent of sunscreen users were unsure if their sunscreen provided broad-spectrum protection."

2. Just a little dab will not do.

Most people apply only 1/4 the needed amount of sunscreen. The ASC recommends at least one ounce (a shot glass) of sunscreen to be used to cover the arms, legs, neck and face of the average adult. Also, sunscreen can wear off, so reapply after every two hours or after sweating or swimming.

That means a family of four should use at least 8 oz. of sunscreen for a four-hour stay at the beach.

3. SPF 30 is not twice the protection as SPF 15.

The Sun Protection Factor (SPF) is the fraction of sun-burning rays that reach your skin, so SPF 15 means only 1/15 of UVB rays will reach the skin. SPF 30 can filter out 97 percent of UVB rays, whereas SPF 50 filters out 98 percent. The FDA has seen no evidence supporting that SPF values higher than 50 provide any additional protection.

4. Apply sunscreen while outside is already too late.

Sunscreen takes about 30 minutes to be absorbed into your skin, according to the SCF, so apply before going outside.

5. There's no such thing as "waterproof" sunscreen.

Sunscreens are no longer allowed to be labeled as "waterproof" due to recent FDA regulations. Any product claiming "water resistant" must declare if you can expect protection for either 40 or 80 minutes of swimming or sweating. However, it is still recommending that you reapply sunscreen after getting wet.

Who and when should you wear sunscreen? Everybody and all the time.

Some common myths denying the need of sunscreen still prevail today, and they're dangerously wrong, says the SCF. Even if it's cold or cloudy outside, you still need to wear sunscreen. Up to 40 percent of the sun's UV rays reach the earth on a completely cloudy day.

Developing a "base tan" does not protect you from UV radiation or sunburning. Any tan is a sign of sun damage to your skin, reports the SCF, and only provides up to protection equivalent to SPF 3 or less.

You can also help combat sun exposure by wearing clothes, a hat and wrap-around sunglasses. Darker sunglasses do no necessarily mean better UV protection, but look for a pair that advertises UV absorption or that it meets ANSI requirements. Keep in mind, however, that a normal t-shirt has an SPF rating lower than 15.

When you do have a burn, you should act immediately to minimize the damage. Since it's a real burn, you need to first lower your body temperature. Jump in a cold shower, apply an anti-inflammatory lotion with aloe vera, and consider taking an ibuprofen to reduce swelling and redness. Do not use bar soap, luffa brushes and acne medications with salicylic acid as they can further irritate your skin. A 1st degree burn should be gone within a week, while a 2nd degree burns (blistering) can take a couple of weeks. If you feel ill or faint, you may have heat stroke and should see a doctor immediately.

While you're out in the sun and soaking up all that summer has to offer this season, be sure to keep yourself and your family safe from the dangers of too much sun exposure.