We have their verdict—plus, the answers to more sunscreen questions you didn't realize you had.
Which Sunscreen Works Better: Spray vs. Lotion? Dermatologists Reveal 5 Rare Sunscreen Facts
Updated on Apr. 26, 2024
Remember the days when the thought of “sunscreen” called to mind the image of a beach lifeguard’s nose slathered in white? Science has advanced significantly since we were young, and today many of us heed how important it is to protect the whole body—for the whole year—from the sun’s potential damage.
But increasingly, maybe you’re beginning to learn that really skillful sunscreen use takes a little know-how. In summer 2021, three major sunscreen brands recalled products due to potentially harmful chemicals in their ingredients, and this past spring, the Environmental Working Group (EWG) released their 16th annual report on possible toxins in some sunscreens. (We spoke with doctors to narrow down the active ingredients that are considered safest and most effective—read Sunscreen Safety Is Under Fire This Summer—Doctors Share the Facts.)
In our research, The Healthy @Reader’s Digest has learned several other important insights about how you’re using sunscreen that just about anyone who cares about skin health would probably want to know. Here, a few of the nation’s leading scientists and dermatologists enlighten us with the latest wisdom.
The 5 Best Hormone-Safe Sunscreens, Recommended by Doctors
First, to understand: is benzene bad for me?
In 2021, a third-party investigation that tested 294 unique batches of sunscreen and after sun care products found that 27 percent of products tested contained trace amount of the human carcinogen, benzene.
All the dermatology and science experts we interviewed explained that benzene is not intentionally added to any skincare products, so it’s not something you’d see on a label of ingredients. “The source of this contamination is currently being investigated by the FDA,” explains Carla Burns, the Environmental Working Group’s (EWG) senior director for cosmetic science. “It may be from a specific ingredients or introduced during the manufacturing process,” Burns said. “We’re just not sure yet.”
On the other hand, Adam Friedman, MD, FAAD, a professor and the chair of dermatology at the George Washington School of Medicine and Health Sciences in Washington, D.C., says the contaminated products contained trace amount of benzene and not all levels of benzene exposure are linked with cancer. “In fact there’s no reported case of topically applied benzene products causing cancer,” he says. “The evidence linking benzene to cancers of the blood, or haematological cancers, shows this risk comes from inhalation and ingestion of benzene, primarily in people who work in occupations where they’re constantly exposed to it.”
Friedman says some companies pulled their products off the market in response to the benzene scandal. But he thinks this was done more in response to public perception than concern over health hazards.
Darrel Rigel, a clinical professor and the director of the Melanoma Surveillance Clinic at the Mt. Sinai Icahn School of Medicine in New York City, suggests that you get far more benzene exposure when you fill up your gas tank than you would using the contaminated sunscreens. Cigarette smoke and motor vehicle exhaust are also major sources of benzene exposure. Many other products also contain benzene, such as plastics, pesticides, cleaners, detergents, perfumes, dyes, and some pharmaceuticals.
Rigel says a study came out after the benzene contamination investigation. The researchers divided 14,000 participants into groups of sunscreen users and non-sunscreen users. The intriguing outcome was that average blood benzene levels were actually highest in non-sunscreen users.
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Which is safer: spray sunscreen or sunscreen lotion?
With the benzene background in mind, a 2021 investigation found benzene contamination in US sunscreens, 32 out of the 40 most contaminated products, or 80%, were spray sunscreens.
Burns says this is one reason the EWG recommends consumers should avoid aerosol sunscreens. The EWG points out that in comparison to lotion sunscreens, spray sunscreens can be very hard to apply evenly or in adequate levels. For example, when applying a spray sunscreen in windy conditions, some product will blow away and not make contact with the skin.
But Rigel and Friedman say that in general, the potential benefits of spray sunscreens likely outweigh the risks. Rigel says they can make it easier to coat young children and to apply sunscreen in places where you have a lot of hair, like the scalp. Yet both recommend spraying the sunscreen into your hand then applying it, versus spraying it directly onto the skin.
How to make sure your sunscreen hits just right
Friedman told us that to make sure your sunscreen’s ingredients are well distributed throughout the container, it’s important to give them a good shake.
The experts noted how doing this, plus applying liberally and often, can ensure your sunscreen will work effectively.
Your sunscreen’s protection is based on the sun’s intensity
SPF values are calculated based on the amount of UV radiation exposure, not the length of exposure. This means the same SPF value will offer protection for shorter periods in accordance with the sun’s intensity, which varies throughout the day.
According to the FDA, one hour of UV exposure at 9:00 a.m. and 15 minutes of exposure at 1:00 p.m. expose you to a similar amount of UV radiation. This helps explain why authorities urge you to avoid sun exposure during peak UV hours, in particular between 10 a.m. and 4 p.m.
Is a higher SPF really better?
The EWG argues that high SPF products are dangerous because they offer a false sense of security to users. People who apply products with very high SPF protection may think they need to reapply sunscreen less often or can safely spend longer periods in the sun. The FDA has proposed an order to change sunscreen regulations and seek to enforce a maximum allowable labelled SPF of 60+.
But Rigel and Friedman say that these issues are user problems, not problems with the actual SPF protection of products. And according to the Skin Cancer Foundation, higher SPF values are more protective.
For example, a SPF 30 product only allows around three percent of UV rays to contact the skin, where as an SPF 50 product allows around two percent. This may not sound like a big difference, but in this scenario the SPF 50 product offers around 50 percent greater protection from UV rays.
So is a higher SPF really better? The answer is probably yes.
What does “reef-friendly” mean on my sunscreen label?
Several years ago, some studies also found that some sunscreen UV ingredients, in particular oxybenzone and octinoxate, could harm marine life, especially the organisms that make up coral reefs.
But upon further review, these initial concerns may be exaggerated. Rigel and Friedman say that the studies that found that oxybenzone may harm marine life were done exclusively in the lab and involved concentrations of oxybenzone that would not realistically occur in nature. For example, some studies used oxybenzone concentrations around 1,000 times higher than found in natural environments.
This isn’t to say that sunscreen ingredients don’t harm marine life, but it seems the relationship is much more complicated than initially reported.
The most important piece of the puzzle—how chronic exposure to lower levels of all UV filters impact marine life—remains unknown. And while most sunscreen products labelled “reef safe” or “reef friendly” don’t contain oxybenzone or octinoxate, the impact of other UV filters in these products, including mineral-based UV filters, requires more research.
A 2014 study found that titanium dioxide produces hydrogen peroxide, a chemical known to harm marine organisms. Further research shows that when corals are exposed to zinc oxide nanoparticles it causes fast and severe bleaching (death). Yet the Skin Cancer Foundation claims that most studies on the matter assess the impact of uncoated zinc oxide and titanium dioxide, whereas most sunscreens contain coated zinc and titanium dioxide.
In 2021, the FDA announced it was filing a notice of intent to create an Environmental Impact Statement under the National Environmental Policy Act (NEPA) to evaluate the impact of sunscreens with oxybenzone and octinoxate on the environment.
The National Academy of Sciences (NAS) has also formed a committee to explore the impact of sunscreen ingredients on marine life whose conclusions should be released some point in 2022. The NAS committee is also be assessing the potential public health impact of people changing their sunscreen habits in response to worries about sunscreen’s environmental impact.
Regardless of the lack of concrete data linking oxybenzone with harmful effects in humans and marine life, Burns says they’ve seen a major shift in the last few years where the ingredient is being used in sunscreen products far less often.
“I think this is due to a combination of consumer education but also there’s been some legislation in regards to oxybenzone’s impact on reefs and aquatic toxicity,” she says. “There are a lot of countries, nations, and regions that have prohibited the sale of products that utilize oxybenzone to protect their marine life.”
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