(NEXSTAR) — We all know the reminders to wear sunscreen when the summer months roll around. And you may also find yourself, sometimes reluctantly, applying sunscreen before heading to the water park, beach or other summer events.
But applying sunscreen correctly is more than just spraying a quick layer on your arms or rubbing in a white blob of lotion. You may be unwittingly making some mistakes when it comes to sun protection.
Here are five things you may be doing wrong with sunscreen.
1. Not using sunscreen at all
It’s no surprise that not wearing sunscreen when you’re out in the sun can be a big mistake. Despite recent claims on social media that wearing sunscreen causes cancer, health officials claim that wearing sunscreen actually prevents cancer.
“To our knowledge, the ingredients in sunscreens sold in the U.S. are all FDA-approved and none of them have been linked to cancer,” Dr. Shilpi Khetarpal, a dermatologist at the Cleveland Clinic, told Nexstar, adding that “by not using sunscreen, you increase your risk of developing skin cancer, specifically basal cell and squamous cell cancer.”
Research has shown that sunscreen can protect against common skin cancers, although the degree of protection will vary depending on the UV radiation associated with skin cancer formation.
2. Not using enough sunscreen
If point #1 doesn’t apply to you (because you apply sunscreen), this could be because you’re not using enough sunscreen.
According to Khetarpal, an adult’s full-body application of sunscreen is one ounce, or the equivalent of a shot glass. If you use a spray sunscreen, she recommends spraying it on until your skin glows.
“The bottom line is that you need to apply more than you should, or just make sure you’re applying liberally and generously,” Khetarpal said.
3. Putting on sunscreen at the wrong time
You can put on all the sunscreen you want, but if you wait until the end of your day at the beach to apply it, it probably won’t do you any good.
When you apply sunscreen will depend on what you’re doing outdoors. For example, if you’re sitting on the patio, you’ll want to apply sunscreen before you go outside — it will start working “relatively quickly,” Khetarpal says.
If you are going to be sweating, swimming, or otherwise interacting with water, you should apply sunscreen 30 minutes beforehand. This will allow the water-resistant effect to take effect.
4. Forgetting to reapply sunscreen
Aside from applying the right amount of sunscreen with enough time for it to take effect, you will most likely need to reapply it.
If you’re not sweating or getting wet, you’ll need to reapply every two hours, Khetarpal said. If you are getting wet, she recommends reapplying after you get out of the water — make sure to dry yourself off first. You may choose to reapply sooner than two hours, especially if you’re sweating.
5. Use up the bottle of sunscreen left over from last year
You may have found a partially used bottle of sunscreen from last summer in your closet. Before using it, Khetarpal recommends checking the expiration date.
Just like with food, once the expiration date has passed, the quality of sunscreen is likely to have diminished. According to Khetarpal, sunscreen loses its effectiveness once the expiration date has passed. At that point, it’s a good idea to buy a new container.
When choosing the best sunscreen, experts recommend looking for a broad-spectrum sunscreen with an SPF of at least 30. If you’re going to be swimming or sweating, you may also want to opt for a sunscreen that’s water-resistant.
You may also want to check the ingredients. Sunscreens with zinc oxide and titanium dioxide work like a shield, reflecting rays away from the skin. Those containing chemicals like oxybenzone and octinoxate work more like a sponge, absorbing the sun and breaking it down.
It’s worth noting that oxybenzone and octinoxate are part of a group of chemicals commonly used in sunscreens that are not considered GRASE (generally recognized as safe and effective) by the Food and Drug Administration. Instead, the agency says “additional data is needed to demonstrate” that sunscreens containing these chemicals “are GRASE.”
However, the FDA cautions that this does not mean that oxybenzone and octinoxate are not safe for use in sunscreens. More information is needed to determine whether they are GRASE. The Centers for Disease Control and Prevention recommends using sunscreens with less than 5% of either.
Zinc oxide and titanium dioxide are considered GRASE ingredients because the FDA “has found sufficient safety data…to support a proposal that sunscreen products containing these ingredients (in concentrations up to 25%) are GRASE.”
