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All You Need to Know About SPF and Sun Protection

mccance blog sunscreenChoosing the right sunscreen can be as difficult as deciding on your next vacation destination. With so many unique formulas and SPF levels ranging from 15 to 100+, you may be wondering what all of it really means in the grand scheme of UV defense. Let’s break down the topic of sun protection so that you can make a quicker, smarter decision and spend more time outside than in the sunscreen aisle.

First, how does sunscreen work? Sunscreen is a combination of physical and chemical materials that filter sunlight as it reaches your skin. These physical ingredients, such as zinc oxide and titanium oxide, reflect and scatter harmful ultraviolet (UV) radiation, while the chemical ingredients like octyl methoxycinnamate and oxybenzone dissipate the UV radiation as heat. As some of the sun’s rays are being dispersed, there is still a filtered portion of sunlight that penetrates the skin as UV radiation. The three types of UV radiation are UVA, UVB, and UVC; however, you are probably most familiar with UVB, which is involved with the burning and tanning of skin.

All sunscreen has an SPF component which stands for sun protection factor, and specifically refers to the level of defense against these UVB rays. The three standard SPF levels to refer to are 15, 30, and 50 and will protect your skin percentage-wise from UVB rays as follows:

  • SPF 15 blocks 93% of UVB rays
  • SPF 30 blocks 97% of UVB rays
  • SPF 50 blocks 98% of UVB rays

Many sunscreens will advertise SPF levels about 50 and even up to levels of 100+. While this may seem like the obviously safest choice for sheer level of protection, dermatologists note that with any sunscreen containing an SPF above 50, the increase in UVB protection is a marginal difference and is ultimately unnecessary – and it may make the user falsely confident about staying in the sun longer. Choosing a formula with an SPF between 15 and 50 will offer adequate protection when applied correctly.

It’s just as important to protect against UVA rays as well as UVB. UVA rays penetrate the skin deeper than UVB rays to cause more long-term damage and aging. SPF only refers to protection against UVB rays, so when choosing a sunscreen, it’s very important to look for a formula with broad-spectrum protection. These products contain UVA-fighting ingredients such as avobenzone, ecamsule, zinc oxide, and titanium dioxide and have “broad spectrum,”  “multi-spectrum” or “UVA/UVB spectrum” protection.

You also should consider how you will be spending your time in the sun. The sun’s rays are strongest between 10am and 4pm, so it’s best to protect your skin during those hours for optimal defense. Even on seemingly cloudy or overcast days, SPF is still extremely important as UV rays are still harmful, even when they’re not as visible.

Also, keep in mind what activities you will be participating in: swimming, biking, running, and yard work all require sunscreen but choosing a specific formula may be helpful. If you’re going to be sweating or spending time in the water, choosing a water-resistant formula could help reduce the amount of reapplications needed throughout the day. While no sunscreen is waterproof, certain formulas can hold their protection level for up to 40 or 80 minutes of water or high-sweat activity and will be labeled accordingly. But be sure to reapply every two hours or so in the sun, or immediately upon drying off after swimming or sweating. It should ultimately be up to you, not the directions on the packaging, to take care of reapplying sunscreen. Recent allegations against Jessica Alba’s The Honest Company’s sunscreen claim that applying the sun protection actually resulted in getting sunburned. Regardless of the formulation issue, as the consumer you must be mindful of when and how much you reapply.

Spray sunscreens — compared to lotions — are known for their easy, quick application. They also provide convenient coverage, especially in hairy areas, such as the nape of the neck, and dry quickly and clear. Lotions are a great option if you tend to have dryer skin as they are very moisturizing and hydrating. While they do require some rub-in time and can be a bit messy, they offer the same protection. A recent test conducted by FutureDerm found that the effectiveness of spray versus lotion sunscreen wasn’t in the protective ingredients, which are similar, but in the application. The study found that sprays administer less sunscreen, only 0.5 milligrams per 2-3 second spritz, which is about one-quarter of the protection needed. In order to get the same level of protection as the average lotion application, be aware that you need to double the application time of a spray sunscreen for about 4-6 seconds.

Sunscreen is just the first step in sun protection. Consider hats and loose fitting clothing that covers your shoulders, neck, back, and other quick-to-burn areas as a great way to keep cool and sunburn-free. Also, never forget the importance of wearing sunglasses. Your eyes need protection just as your skin does from both UVA and UVB rays so look for lenses with 95-100% ultraviolet protection.

What are some of your favorite broad-spectrum SPF formulas? Leave a comment on our Facebook page.