Let’s be honest. We’re wasting precious time and money when we invest in skincare products and procedures, but don’t use sunscreen daily. Wearing sunscreen is the single most beneficial thing you can do to maintain healthy, young-looking skin. But even among sunscreen users, studies show that most people aren’t getting enough sun protection. And, there’s no such thing as safe tanning with UV light. So, how can we do a better job of protecting ourselves and our families? What should you look for in sunscreen? Is there a difference between physical and chemical sunscreen? Is one better than the other? This article explains sunscreen terminology and will help you decide which is best for you.
Why wear sunscreen at all?
Although this article focuses on premature aging caused by overexposure to sunlight, we shouldn’t forget it’s also harmful to our skin in general. According to the Surgeon General, “Skin cancer is the most commonly diagnosed cancer in the United States, and most cases are preventable” (1). So, daily use of physical or chemical sunscreen has a health benefit, too. But when it comes to premature aging, environmental factors, such as UV exposure, can affect how our skin naturally ages. Some other factors include “ionizing radiation, severe physical and psychological stress, alcohol intake, poor nutrition, overeating [and] environmental pollution” (2). But of all the environmental factors that can cause premature skin aging, exposure to solar radiation accounts for 80%. In other words, the most significant cause of premature aging is too much sunlight.
However, there is a flip side. Being outdoors is linked to better mental and physical health. This is because most physical exercise takes places outdoors, and sunlight (UVB) promotes vitamin D production in the skin. Vitamin D is essential for bone health and preventing other numerous chronic diseases, including heart disease, diabetes and autoimmune conditions. Therefore, completely avoiding the sun is not a healthy option either. Using a physical or chemical sunscreen is one way to get the benefits we need from the sun while protecting our skin from photodamage (sun damage). But it needs to be used correctly. And with so many different formulations on the market, it’s hard to know which is right for you.
Let’s take a closer look at sunscreen terminology
There are 3 types of UV rays, but only two hit the earth’s surface. These rays are ultraviolet A (UVA) and ultraviolet B (UVB). “UVA comprises 96.5% of the UV radiation reaching earth, leaving UVB only with the remaining 3.5%” (3). Although UVA is the predominant UV light reaching the earth’s surface, UVB is the most energetic and causes skin reddening and sunburn. However, that doesn’t mean UVA can be ignored.
In fact, UVA can be more concerning because it penetrates deeper into the skin and quietly wreaks havoc. UVB directly harms DNA, but UVA promotes free radical production, which slowly damages skin cells over time. These two solar wavelengths get a lot of attention when it comes to sunscreen but, UV radiation is only 10% of the entire electromagnetic spectrum reaching the earth’s surface. There’s also high-energy visible (HEV) light (400-500 nm), a subset of the visible light spectrum and infrared light. See Figure 1 below.
Figure 1
No sunscreen, physical or chemical, protects you from all solar radiation. And, each active ingredient specializes in specific wavelengths measured in nanometers (nm). But, choosing a product with broad-spectrum protection and high sun protection factor (SPF) is a good start.
SPF refers only to the amount of UVB protection a sunscreen provides. The methods used to determine the amount of UVA and UVB protection a sunscreen provides are different. So, the amount of UVA protection cannot be combined into the SPF. “Broad-spectrum” protection means the product protects against both. In its most recent proposal, the Food and Drug Administration (FDA) asks that the amount of UVA protection be equal or close to the SPF indicated for UVB. However, they do not require the amount of UVA protection to be listed on the product label. UVA protection is indicated on sunscreen products in Asia and Europe using a PA+ to PA++++ rating system. The more + symbols, the greater the protection. Some US companies are starting to adopt the same system.
Some additional information about SPF
The FDA website also states the following, “There is a popular misconception that SPF relates to time of solar exposure. For example, many people believe that, if they normally get sunburned in one hour, then an SPF 15 sunscreen allows them to stay in the sun for 15 hours (e.g., 15 times longer) without getting sunburn. This is not true because SPF is not directly related to time of solar exposure but to amount of solar exposure” (4). In other words, it’s hard to determine how much sun exposure you’re actually getting. In addition, sun intensity can depend on the time of day, time of year and geographical location. So reapply sunscreen every two hours regardless of the SPF you’re using.
Another distinction people sometimes make is, “SPF 30 allows about 3 percent of UVB rays to hit your skin. An SPF of 50 allows about 2 percent of those rays through. That may seem like a small difference until you realize that the SPF 30 is allowing 50 percent more UV radiation onto your skin” (5). So, use the highest SPF offered for the product you like. Don’t settle for SPF 30 if better protection options are available. Dermatologists recommend a minimum of SPF 30.
Other sunscreen terminology
To prevent a false sense of security regarding how much sun protection you’re getting from sunscreen, the FDA prohibits the use of two terms. They are “waterproof” and “sunblock.” The FDA considers these terms misleading because no sunscreen, physical or chemical, is completely waterproof. And, no sunscreen completely blocks the sun’s rays from penetrating your skin. Instead of waterproof, the FDA allows the term “water-resistant” if the SPF level is still effective after 40 minutes underwater. The FDA allows the term “very water-resistant” if the SPF level remains effective after four 20-minute water immersions separated by 20 minutes of air-drying time. Physical sunscreens are sometimes referred to as sunblock, because they reflect and scatter light. But, this term in inaccurate because some UV rays still get in.
More on physical sunscreen
Physical or mineral sunscreens contain the active ingredients zinc oxide or titanium dioxide. These minerals are inorganic so you will not find “organic” mineral sunscreens. Both work on the skin’s surface. It’s commonly believed that they work by reflecting or blocking UV rays. However, a 2016 study concluded that “titanium dioxide and zinc oxide provide UV protection primarily via absorption of UV radiation and not through significant reflection or scattering” (6). Still, physical sunscreens are the safer, toxin-free choice because they sit on top of the skin and do their job from the surface. These minerals rarely get absorbed by the skin.
The exception is micronized titanium dioxide, also known as nano titanium dioxide. Studies show it penetrates the skin more than zinc oxide, but it’s still a relatively low amount. Zinc oxide is the safest sunscreen ingredient. Even when micronized, very little is absorbed, if at all. Baby sunscreens contain only zinc oxide as the active ingredient. Micronized or not, these are the only two ingredients generally regarded as safe and effective (GRASE) by the FDA. So why micronize these minerals at all? And, why doesn’t everyone use mineral sunscreens?
Mineral sunscreens offer good sun protection for specific wavelengths (see Figure 1). However, they also leave a white cast, and depending on your skin tone, it can look weirdly unnatural. Micronizing minerals reduce the white cast by decreasing the surface area that can reflect light. Unless specified, all mineral sunscreens available today are micronized. Also notable is the topical application of nanoparticles is GRASE, but inhaling them is not. For this reason, spray sunscreens are not recommended for the face and around children.
Additional mineral sunscreen ingredients
Recent studies have shown iron oxides to be an effective sunscreen ingredient (7). But what are iron oxides? They are the pigments used in makeup to match skin tone. There are three: yellow, red and black. When mixed with white titanium dioxide, you can achieve any skin tone. It’s effective as a blocker for high-energy visible (HEV) light. HEV light, also known as blue light, falls under the visible light spectrum. In case you’re wondering, it is the same blue light emitted by your screens and LED lighting. HEV light penetrates even deeper into the skin than UVA (see Figure 1). So, tinted mineral sunscreens with titanium dioxide, zinc oxide and iron oxides are the safest, most effective combination. Together, they prevent UVB, UVA and HEV light from damaging your skin.
Chemical sunscreens
Most people agree that physical sunscreen actives are GRASE. Chemical sunscreens, on the other hand, are full of controversy. Chemical sunscreens are designed to be absorbed by the skin. They work with the skin to create a protective layer that absorbs sunlight without harming skin cells. In the US, the FDA regulates sunscreens as a drug “because it makes a drug claim - to help prevent sunburn or to decrease the risks of skin cancer and early skin aging caused by the sun” (4). For this reason, the FDA is more selective about the active ingredients they allow in sunscreens.
Chemical blockers for UVB are relatively common around the world, but UVA blockers are trickier to get right. In the US, the FDA has approved only 4 UVA chemical blockers. However, only 1, avobenzone, is considered very effective. Also, some chemical blockers “are unstable when exposed to UV radiation” (3). Combining chemical sunscreen actives makes them more stable so it’s common to see more than one active ingredient listed.
Chemical sunscreens and the FDA
To expedite the review process for safety and efficacy of active ingredients in sunscreen, Congress enacted the Sunscreen Innovation Act (SIA) in 2014. But, the FDA has not approved any new chemical sunscreen ingredients since 1999. In addition, the FDA has declined several ingredients already approved in Europe, citing a lack of safety and efficacy studies.
According to the FDA, “there is evidence that at least some sunscreen active ingredients may be absorbed through the skin and enter the body. This makes it important to perform studies to determine whether, and to what extent, use of sunscreen products as directed may result in unintended, chronic, systemic exposure to sunscreen active ingredients” (4). The results found the amount absorbed through the skin is much greater than the amount determined to be GRASE by the FDA. For example, oxybenzone can be found in urine, amniotic fluid, blood plasma and even breastmilk. Since chemical sunscreens need to be absorbed by the skin to work, the trick is to get them to stay in the skin and not circulate throughout the body.
Indeed, high absorption does not automatically make these chemicals unsafe. But studies trying to prove the safety of chemical sunscreens have been inconclusive. However, there are two chemicals the FDA has concluded “that the risks associated with use of these active ingredients in sunscreen products outweigh their benefits” (4). They are aminobenzoic acid (PABA) and trolamine salicylate. Nevertheless, the FDA does not prohibit the use of these active ingredients. So, avoid these ingredients when shopping for sunscreens.
Various forms of sunscreen
Sunscreens come in various forms. The most common are creams, but there are also powders, solids/sticks and sprays. The most user-friendly of these are creams and solids. Solids glide over the skin and are especially useful for quick, mess-free application on kids. Powders and sprays are not ideal for different reasons. For sprays, there’s a high possibility of inhalation and accumulation in the lungs. And, for powders, the amount required to achieve the SPF listed far exceeds the amount a person can reasonably use. Used alone, powders do not protect enough. See below for a reference picture.
Babies and kids
Babies under 6 months should not use sunscreen, physical or chemical. They should be shielded from the sun by protective clothing and shade only. Kids under 2 should only use physical sunscreen because of chemical absorption into the body and their unknown effects. It’s also notable that “many chemical sunscreens have been reported to cause allergic or photoallergic reactions” (3). And, younger children are more susceptible to allergic reactions to chemical sunscreens than adults. However, it’s not uncommon for adults to experience a reaction to chemical sunscreens, too.
For babies and kids, try to avoid products that combine sunscreen and bug repellent. Bug repellent contains ingredients that you want to use as little as possible, and sunscreens are something you want to apply liberally and often. The two do not make a good combination. Apply them separately instead.
Sun protection best practices
It’s best to use a broad-spectrum sunscreen with a minimum SPF of 30 daily whether you plan to go outside or not. UVA and HEV light can penetrate windows and sunscreens also keep you protected if you go out unexpectedly. When you plan to be outside for an extended period, use a broad-spectrum sunscreen with SPF 50+. You may have heard that 1/2 teaspoon is the right amount to use on the face. But different people have different-sized faces, so it’s better to make sure you have a thin even coat over your entire face. Then, wait 10-15 minutes for the sunscreen to set before applying makeup or going outside. Reapply sunscreen every 2 hours throughout the day if you’re going to be outdoors and active. And always reapply after sweating or getting wet.
Unfortunately, there’s no sunscreen, physical or chemical, that can protect you from all solar radiation. So, use protective clothing, hats, sunglasses and stay in the shade when possible. The use of sunscreens does not make it okay to spend extended periods of time baking in sunlight. And, when deciding whether physical or chemical sunscreens are better, the best choice is the one you will use most consistently. However, it may take some trial and error to find the right sunscreen for you. To that end, we tested over 50 sunscreens so you don’t have to. Using the information above, we chose only the ones that we were happy to use daily for our curated picks below.
Lastly
Always pay attention to the expiration date. After physical and chemical sunscreens expire, the active ingredients degrade and are no longer effective. Consequently, for products with no use-by date listed, the FDA advises, you should discard those sunscreens 3 years after the purchase date. And store sunscreen away from heat and direct sunlight.
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Curated Picks
Best sunscreens for no-makeup days
Ilia: This first of its kind serum-sunscreen-foundation hybrid product may sound like it’s trying to do too much, but it delivers on its promise. It provides a dewy finish with light foundation coverage and is available in 24 different shades. Its active ingredients, non-nano titanium dioxide and zinc oxide, provide UVA/UVB protection and iron oxides protect against HEV light. Meanwhile niacinamide, hyaluronic acids and plant-based squalane work to smooth fine lines, brighten and moisturize the skin. It is SPF 40.
Suntegrity: This SPF 30 sunscreen is for those with normal to dry complexions who want a perfect satin finish. When first applied, it will look a bit on the greasy side. However, after it sets, the finish becomes more like a lit from within glow. The 5 in 1 description covers the following attributes: it renews, hydrates, protects, primes and covers the skin. This sunscreen also made the Environmental Working Group’s (EWG) 2019 “Best Moisturizers with SPF” list and received a #1 Rating in the Skin Deep Cosmetic Safety Database.
Australian Gold: Made for those with any skin type who want a perfect matte finish that doesn’t look dull. This SPF 50 sunscreen feels like whipped mousse and spreads smoothly to even skin tone. It contains titanium dioxide, zinc and iron oxides to protect you from UVA, UVB and HEV light. It’s also full of antioxidants from kakadu plum, eucalyptus and red algae to fight free radicals and leave your skin soft and smooth after one use. The sunscreen is available in 3 tints: light-fair, medium-tan and rich-deep.
Best sunscreens to layer under foundation
The Organic Pharmacy: This non-tinted SPF 50 sunscreen is great under makeup and acts like a primer that grips onto foundation. This lightweight cream applies easily and leaves no white residue. The active ingredients are titanium dioxide and zinc oxide to provide broad spectrum protection. It also contains additional nourishing and hydrating ingredients like aloe, rose hip, shea butter and calendula.
EltaMD: Made for extra sensitive skin types and post-procedural skincare instances, this sunscreen is oil-free and tinted so it provides sheer coverage and sits well under makeup. Worn alone, it gives a satin finish, somewhere between matte and dewy, depending on whether you have oily or dry skin. It is SPF 41 and provides broad spectrum protection with active ingredients titanium dioxide and zinc oxide. Tinted with iron oxides, this sunscreen leaves no white cast.
Ultrasun: This Swiss made sunscreen is known for its long lasting protection. It is made using EU standards, which ban over 1,300 chemicals due to their toxicity. Although this is a chemical sunscreen formula that protects against UVB, UVA and HEV light, Ultrasun considers potential toxicity when choosing ingredients. This formula absorbs quickly, leaves no white cast and a perfect satin finish. It is moisturizing, has anti-aging ingredients and is ideal for sensitive skin prone to pigmentation.
For the kids
Babo Botanicals: These non-nano zinc oxide sunscreen sticks are SPF 50 and helpful for keeping sunscreen out of kid’s eyes. The stick format makes applying sunscreen quick and less messy. They are also small, purse-friendly and have broad spectrum protection.
Babo Botanicals: Sometimes, a cream format is preferable when there’s a large surface area, like arms and legs. This SPF 50 non-nano zinc oxide sunscreen is gentle enough for young skin and gives broad spectrum protection. It also dries more sheer than most zinc sunscreens for kids.
Publications
(1) General, Office of the Surgeon. “Skin Cancer Reports and Publications.” HHS.gov, 12 Mar. 2021, www.hhs.gov/surgeongeneral/reports-and-publications/skin-cancer/index.html.
(2) Poljšak, Borut, and Raja Dahmane. “Free Radicals and Extrinsic Skin Aging.” Dermatology Research and Practice, Hindawi Publishing Corporation, 2012, www.ncbi.nlm.nih.gov/pmc/articles/PMC3299230/.
(3) Leslie Baumann, MD, Cosmetic Dermatology, 2nd edition, Sunscreens, Chapter 29 - pages 245-255.
(4) Center for Drug Evaluation and Research. “Sunscreen: How to Help Protect Your Skin from the Sun.” U.S. Food and Drug Administration, FDA, www.fda.gov/drugs/understanding-over-counter-medicines/sunscreen-how-help-protect-your-skin-sun.
(5) Wang, Steven Q. “Ask the Expert: Does a High SPF Protect My Skin Better?” The Skin Cancer Foundation, 2 Apr. 2021, www.skincancer.org/blog/ask-the-expert-does-a-high-spf-protect-my-skin-better/.
(6) Cole, Curtis, et al. “Metal Oxide Sunscreens Protect Skin by Absorption, Not by Reflection or Scattering.” Wiley Online Library, John Wiley & Sons, Ltd, 10 Nov. 2015, onlinelibrary.wiley.com/doi/full/10.1111/phpp.12214.
(7) Bernstein, Eric F., et al. “Iron Oxides in Novel Skin Care Formulations Attenuate Blue Light for Enhanced Protection against Skin Damage.” Wiley Online Library, John Wiley & Sons, Ltd, 18 Nov. 2020, onlinelibrary.wiley.com/doi/full/10.1111/jocd.13803.
