Living Well

What’s SPF in Sunscreen? SPF Level Breakdown

Sunscreen comes in all shapes, sizes, and most importantly, SPF values. When you go shopping for sun protection, you'll likely face a wall of countless SPF numbers emblazoned across colorful bottles, ranging in SPF value from as low as 2 (those with fair skin, beware) to as high as 110. But before you side with a specific brand or a type of sunscreen, you should know what is SPF?

We're going to give you an SPF level breakdown on what SPF in sunscreen is and how it works to help take the guesswork out of your UV protection. (Bonus: knowing what SPF is can make for some impressive poolside conversation.)

What's with all the acronyms?

Science usually has ways of consolidating really long words into things like SPF, UVA, UVB - but don't let these words intimidate you. Let's start here: What does SPF stand for? SPF stands for sun protection factor, and is a relative measurement of how long you are protected from UVB rays. You're probably thinking, "OK, so how about those UVB rays?" We'll get into that next, but let's go in alphabetical order. It's important to remember that the sun is a powerful thing, and its light is made up of different types of rays: UVA and UVB. According to the University of Iowa Hospitals & Clinics, these rays are both forms of ultraviolet light that play a role in the damaging of skin, from sunburn to skin cancer formation.

UVA rays affect your skin differently than UVB rays and attribute to things like premature skin aging, also known as wrinkles. UVB rays, on the other hand, cause sunburn and play a crucial role in the cause of skin cancer according to the Skin Cancer Foundation.

How does SPF work?

Now that we've gotten the acronyms out of the way, let's hone in on how SPF works. First, you should know that SPF is measured by its effectiveness in blocking the sun's UVB rays, not UVA rays. Remember, UVB rays are responsible for sunburn, which is exactly how SPF gets its number. Let's break it down.

The SPF value represents the factor in which you are likely to burn. In an example used by Skin Cancer Foundation, the SPF number is a multiplier of how long it takes your skin to burn without the use of sunblock. So that means if it takes your skin 10 minutes to burn without the use of sunscreen, then wearing a sunscreen with SPF 30 will take you 30 times as long to burn, assuming you applied it properly (always follow the directions provided by the sunscreen company).

More detail on broad spectrum protection

Getting back to those UVA rays. You may be wondering how the SPF number plays into the protection from UVA rays. That's where broad-spectrum sunscreen comes in. Ensuring you have broad-spectrum sunscreen with a minimum SPF of 15 will mean you're protected from the sun's harmful UVA and UVB rays. Although, that wasn't always the case. According to Skin Cancer Foundation, the FDA "issued new rules for sunscreen labeling," which meant companies had a standard to meet when labeling their products "broad spectrum."

Luckily for tax-free users, eligible sunscreen must carry a minimum of SPF 15 with broad spectrum protection, so the convenience of finding the most-protective UV protection is built directly into tax-free spending.

How does SPF block the rays?

That's the thing, it doesn't. SPF is just the indication of how much protection you will get from that sunblock. (We just went over this.) What does block the rays are the actual active ingredients used in the sunscreen. This is commonly divided into two categories: chemical or mineral. The common active ingredients used in chemical sunscreens (avobenzone or oxybenzone) actually absorb the Uv radiation, break it down, and release it as heat, as described by Live Science.

In comparison, mineral sunscreens which commonly use ingredients like zinc oxide and titanium oxide, are (as their name implies) physical minerals that sit atop your skin and physically reflect the UV rays. Sure, it doesn't sound nearly as scientific, but it is effective and a great alternative for those who have sensitive skin and are interested in more environmentally conscious options. Find which sunscreen is right for you and stick with which protects you best.

Does a higher SPF block more rays?

Technically, yes. Sunscreens do their best to block as many UVB rays as possible, but no sunscreen blocks 100 percent of all UVB rays. As determined by, sunscreens with high SPF values of 100 and more, may not be more protective than an SPF 30 or SPF 50, which already blocks 97-98 percent. There's also the risk of entrusting higher SPF values to protect you for longer than lower SPF numbers, which can put you and your loved ones at risk of UV damage.

The sun doesn't deserve all this bad rap though. While its UV rays can be harmful, moderate amounts of exposure to sunlight is beneficial to your health. You may have heard that sun exposure is important for the production of vitamin D, which is true! According to the Skin Cancer Foundation, it only takes about 10-15 minutes of exposure to the sun on the arms, legs, abdomen, and back, two to three times a week to benefit from the sun's rays. The Foundation also explains that UVB rays are responsible for "triggering vitamin D production in the skin." While SPF indicates the protection from UVB rays, there's no proof that shows higher SPFs can diminish your body's ability to maintain vitamin D sufficiency.


From SPF to UVA and UVB, the most important takeaways you should have on your next sunscreen purchase should include: broad spectrum, a minimum SPF 15 value, and most importantly, follow the directions! Don't be fooled by high SPF numbers and always remember to reapply your sunscreen throughout the day! Now take what you've learned about SPF and impress a friend or two next time you're poolside.

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Living Well

What SPF Should I Use?

The sun plays a very important role in our everyday lives. It helps keep our sleep pattern on track and helps our bodies produce Vitamin D, which is important for bone function and healthy skin. But like most things, it's only good in moderation. And for those who love the sun, you probably have a hard time accepting that.

The truth is, too much sun exposure is harmful to your skin, which is why we require protection from the sun's harmful ultraviolet rays. Deciding how much and what kind of protection you need depends on many factors. That's why we've put together an easy guide to help you choose the right protection.

All about UV

When considering sun protection, it's probably best to understand what exactly you're protecting yourself from. The sun's rays are made up of UVA and UVB rays, both of which can cause skin damage, but in different ways. According to the Skin Cancer Foundation, UVB rays cause sunburn and play a crucial role in the cause of skin cancer. While UVA rays are responsible for that glowy tan you're after, they're also wreaking havoc on your skin causing damage via aging and wrinkles.

A sunscreen's SPF protection refers to the protection it provides from the sun's UVB rays. So you're probably wondering, "What about UVA radiation?" That's where broad-spectrum protection comes in. Sunscreens with broad-spectrum protection do their best to block the entire spectrum of UV rays emitted by the sun, which is especially important when considering the harm UVB rays and UVA rays each cause.

Now that you understand what you're protecting yourself from, let's take a deeper dive into the pool of SPF so you can better understand which SPF number is right for you.

Shining a light on SPF

Not all SPFs are treated equally. So, before you ask yourself which SPF you should use, let's talk about what SPF is. The first question to consider is: what does SPF stand for? SPF is short for "sun protection factor," which indicates the effectiveness of a sunscreen vs. not wearing sunscreen. Sunscreens have many different SPF values from as low as 4 to as high as 110.

Understanding this value and what these numbers mean is essential to choosing the right SPF. According to, SPF 15 blocks 93% of UVB rays, SPF 30 blocks 97% of UVB rays, SPF 50 blocks 98% of UVB rays, and SPF 100 blocks 99% of UVB rays, but no one sunscreen blocks 100%. This also does not mean a higher SPF number provides longer UV protection. I know, we promised this was going to be an easy guide, but bear with us, this part is important: SPF 30 and SPF 80 both last the same amount of time, they just offer different degrees of protection within that time frame. That's why questions like when, how much, and how often you apply sunscreen are key.

So how much is enough sunscreen?

Great question. The answer is: it depends. To practice safe sun exposure, we recommend following the instructions provided by your sunscreen product; however, there are some hard and fast rules that apply to good skincare practice.

According to, a good rule of thumb when you apply sunscreen is "one teaspoon per body part" of exposed skin. No one expects you to bring your baking set to the beach to ensure you're accounting for the proper amount, but it wouldn't hurt to measure out a teaspoon of sunscreen in your hand so you can get used to what that measurement looks like.

While this is a helpful tip, it doesn't take into account how body surface area differs from one individual to another. In that case, it's best to make sure no piece of skin goes untouched. Applying sunscreen to dry skin, 30 minutes prior to sun exposure is recommended by the Skin Cancer Foundation. This will ensure that the sunscreen has been completely absorbed by the skin to offer maximum protection against sun damage.

Another tip is to reapply, reapply, reapply. We can't stress this enough. According to the American Academy of Dermatology Association, one should reapply sunscreen every two hours or after swimming or sweating. We know, it's never convenient to break up a game of Marco Polo to reapply sunscreen, but you'll thank us later when you're not feeling the stinging effect of sunburn while trying to enjoy your s'mores.

Check your sundial

Luckily for planet earth, the sun never takes a day off, but for us, that means the sun is constantly emitting harmful UV rays. Having said that, it is recommended that you wear sunscreen everyday. But when you are spending time outdoors, the sun is strongest between 10 a.m. and 2 p.m., so your best bet is to make sure you're especially covered during these hours.

Even on cloudy days, up to 80 percent of the sun's harmful UV rays can penetrate your skin. According to the American Academy of Dermatology Association, it's especially important to look out for things like snow, sand and water as their reflective properties can enhance your skin's exposure to ultraviolet rays.

SPF by skin type

This leads us to the second-most-important consideration when choosing SPF and that is your skin type. Whether your skin is oily, dark, or fair, you will need to consider which SPF provides your skin with the maximum protection against sun damage.

For those with normal skin (neither dry nor oily) you're in luck. Any sunscreen is fair game for your skin type. You can pretty much pick your preference whether it may be reef safe, mineral, or chemical (we'll get to these in a bit).

For oily skin, you'll want to make sure you get a sunscreen that doesn't pack on the grease. The Healthy suggests finding a sunscreen with "ensulizole as the UVB blocker, since it's the least greasy." You can also consider a powder mineral sunscreen to avoid the greasiness.

For dry skin, try a sunscreen and moisturizer combo. Another option is finding sunscreens with soothing emollients, which according to Healthline, "coat your skin with a thin oily film that seals the water in your skin," thus keeping your skin hydrated.

And then there's acne-prone skin. Have no fear, there's SPF protection just for you. Search for a lightweight moisturizing sunscreen that is "non-comedogenic," which is a fancy word for, "will not clog your pores and cause acne."

If you have particularly sensitive skin, you may even want to seek shade during the sun's high point of the day. Choosing protective clothing to minimize the amount of skin you have exposed to the sun altogether is also a good idea. Plenty of outdoor apparel retailers offer built-in UPF (ultraviolet protection factor) that blocks both UVA and UVB rays.

And if you have a history of skin cancer, or may be at high-risk for skin cancer, avoiding excess sun exposure may be best. But in the event you find yourself in the sunlight, the Skin Cancer Foundation suggests that SPF 50 may not be enough protection. Consult your doctor about which protection may be right for you.

Chemical or Mineral

There are essentially two different types of active sunscreen ingredients that help prevent UVA and UVB rays, and they are chemical ingredients or mineral (physical) ingredients. Here's how they work:

Chemical sunscreen products use active ingredients like oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate which according to Piedmont Healthcare, absorbs the sun's rays, converts the rays to heat, and releases them from the body.

Mineral sunscreens "work like a shield, sitting on the surface of your skin and deflecting the sun's rays," according to the American Academy of Dermatology Association. These use active ingredients like zinc oxide and/or titanium dioxide and are typically a good alternative for sensitive skin types or even babies and toddlers.

No matter your desired protection, make sure not to miss the top of your head, ears, and even your lips! The American Academy of Dermatology Association recommends a broad-spectrum lip balm with a minimum SPF value of 30 for healthy, sun-kissed lips.

So which SPF is right for me?

You've probably learned by now that there is no one magic number that covers every circumstance, but what you now know are the steps it takes to find out which SPF works best for you when you need it. So the next time you go shopping for sunscreen, find the right SPF by asking yourself the following:

  • Who the sunscreen is for (children or adults)
  • Skin type
  • Sensitivity to sun exposure
  • Amount of time you will be spending outdoors
  • Your preference for the type of SPF protection (chemical or mineral)
  • Lastly, always make sure your sunscreen has not expired

Remember, you can always start with a water-resistant, broad-spectrum sunscreen with a minimum SPF value of 30, which is recommended by dermatologists and research done by credible organizations. (We suggest listening to the pros on this one.) Now put up your broad-spectrum covered feet up and enjoy the great outdoors with peace of mind.

Thanks for visiting the FSA Learning Center! To stay on top of all FSA news that can affect your health and financial wellness, be sure to follow us on Facebook and Twitter.