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Sunscreen is a must, but which type is best?

July 5, 2022
Author and cancer screening expert Susan Cotten breaks down the differences between different types of sunscreen and shares what to look for when you're attempting to decode the labels.

We are well into summer, and each year it seems there are more brands of sunscreen with more options available under each brand. Options for babies, kids, sports, and the beach are just a few I noted on a recent shopping trip. To my surprise, there was also a dark tanning oil with no SPF; I recognized it easily as the one I used in the 1970s when it was cool to have a deep, dark tan and “laying out” in the sun was a common pastime.

Standing in front of the large sunscreen display, I was overwhelmed and thought, “Where do I begin in narrowing my selection to find the optimal sunscreen for my needs as a skin cancer survivor?” This store didn’t have the sunscreen I typically use, and frankly, I had no idea where to begin … with the brand, the SPF, or ingredients! I know people feel overwhelmed when staring at the myriad of options of oral care products and trying to decide which toothpaste, toothbrush, or mouth rinse is best for them. That day in the sunscreen aisle, it was just me and the myriad of sunscreens, and I was at a loss.

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As dental professionals we check the skin of the head and neck during the extraoral evaluation and make referrals to a dermatologist when indicated. We remind our patients to wear sunscreen, tell our children, grandchildren, and others the importance of wearing sunscreen to prevent sunburn and help prevent skin cancer. That begs the question: What is the best sunscreen, and with all of the different options and ingredients, which options are essential? Confused, I went to the best sources I know to find answers: the American Academy of Dermatology (AAD) and the Skin Cancer Foundation.

The AAD recommends sunscreens that have the following verbiage on the label: broad spectrum, SPF of 30 or higher, and water-resistant.1 What do these three things mean to us as consumers?  

Broad spectrum

Broad-spectrum sunscreen aids in protecting against ultraviolet A (UVA) and ultraviolet B (UVB) rays. Both UVA and UVB can cause skin cancer. UVA is associated with the aging of skin and UVB with burning. According to the Skin Cancer Foundation, UVA and UVB can cause eye damage, cataracts, and eyelid cancer. Both UVA and UVB exposure damages the DNA in the skin cells, causing genetic defects, which can then lead to skin cancer. The amount of damage that occurs to the skin depends on the length of time skin has been exposed to UV rays without protection and the intensity of the UV rays. Living where the sun is strong year-round increases someone’s risk.2

“Alarmingly, a new AAD survey showed that when considering a sunscreen, less than half of Americans look for a product with broad-spectrum protection,” says Dr. Lim.1

SPF of 30 or higher

Sun protection factor (SPF) implies how well a sunscreen protects from sunburn. The Skin Cancer Foundation reports the SPF indicates how long it takes to redden the skin using the sunscreen exactly as directed, compared to the amount of time without sunscreen. For example, a sunscreen with an SPF of 30 allows approximately 3% of UVB rays to reach your skin, and an SPF of 50 allows approximately 2% of UVB rays to reach your skin. “That may seem like a small difference,” says the Skin Cancer Foundation, “until you realize that the SPF 30 is allowing 50% more UV radiation to your skin.” They also recommend, regardless of the SPF, to apply one ounce (two tablespoons) 30 minutes before going outside.3

Water resistant

A sunscreen can be water resistant for 40 or 80 minutes, states the AAD. This rating must be on the label.4 Sunscreens are not waterproof and need to be applied every two hours when outside, or after swimming or sweating. At one time, sunscreens were labeled waterproof or sweatproof. Sunscreens are regulated by the Food and Drug Administration (FDA). The FDA prohibits manufacturers from labeling sunscreens as waterproof, sweatproof, or using the term “sunblock” because these terms overstate the effectiveness of the product.5

Physical vs. chemical sunscreens

In addition to the three important factors listed above, there are two types of sunscreen to consider, and they are differentiated in how they protect you from UV rays—physical protection and chemical protection.

Physical sunscreen, also referred to as mineral sunscreen, acts as a physical shield, deflecting the sun’s rays. The active ingredients in a physical sunscreen include titanium dioxide and/or zinc oxide. A physical sunscreen is recommended for people with sensitive skin.1 Physical sunscreens have a thicker consistency than chemical sunscreens and may be preferred by those with dry skin; however, they tend to be harder to rub in and may leave a white film on the skin. Tinted physical sunscreens are available and result in less of the white film.

Chemical sunscreen absorbs the sun’s rays. These sunscreens may have one or more of the following active ingredients: avobenzone, ensulizole, homosalate, octinoxate, octisalate, octocrylene, or oxybenzone. They absorb UV rays from the sun, convert them to heat, and release them from your body so they can’t damage your skin and cause sunburns.6

The Center for Surgical Dermatology Associates states that in most cases, a chemical sunscreen will provide more complete protection from the UV rays, and may be more water and sweat resistant, which may make them a better choice when in the water or participating in sports activities. While they have a lighter consistency and absorb quickly, they may be an irritant to those with sensitive skin or eczema, psoriasis, or rosacea.6

There has been some discussion about the safety of the chemical sunscreens. “The Centers for Disease Control and Prevention (CDC), the AAD, and the FDA have all stated that chemical sunscreens are safe to use. They believe that using sunscreen to prevent skin cancer outweighs the unproven effects of toxicity or health hazards of chemical ingredients.”7,8

Since sunscreen is regulated by the FDA, what do the words, “sport,” “baby,” and “sensitive” mean to us when selecting sunscreen? The FDA has not defined these terms for sunscreens, but in general this is what to expect when you see these words on the labels.

Sport

The "sport" designation typically means it will stay on wet skin for 40 or 80 minutes, which means the sunscreen is water resistant. This is one of the three requirements of sunscreen recommended by the AAD stated earlier.9

Baby

"Baby" sunscreen typically contains the active ingredients titanium dioxide and zinc oxide, which are less likely to irritate a baby’s sensitive skin. These fall into the physical sunscreen category.9

Sensitive

These fall into the physical sunscreen category as well, and have the active ingredients titanium dioxide and zinc oxide. They are also free of paraamino-benzoic acid (PABA), fragrance, oils, and are hypoallergenic.9

All sunscreens have an expiration date. If you are unable to find the expiration date, it is recommended to put the date and year you purchase it on the container, and it should be good for three years.10 Consumer Reports recommends discarding a sunscreen if it has an odd odor, changes in color, or the ingredients appear to have separated.11

Having narrowed down the important things to look for when choosing a sunscreen, your call to action is this: check the label of your sunscreen, does it say broad-spectrum and waterresistant and does it have an SPF of 30 or higher? Also, please share this information with your patients, family, and friends. The Skin Cancer Foundation says protection goes beyond sunscreen. They state, “It’s important not to rely on high-SPF sunscreens alone. No single method of sun defense can protect you perfectly. Sunscreen is just one vital part of a strategy that should also include seeking shade and covering up with clothing, including wide-brimmed hats and UV-blocking sunglasses.”3

Enjoy your summer and stay protected from harmful UV rays!

Editor's note: This article appeared in the July 2022 print edition of RDH magazine. Dental hygienists in North America are eligible for a complimentary print subscription. Sign up here.

References

1. Dermatologists say sunscreen is a vital tool in the fight against skin cancer, the most common cancer in the US. American Academy of Dermatology. May 7, 2019. https://www.aad.org/news/sunscreen-is-a-vital-tool-in-the-fight-against-skin-cancer

2. UVB facts and risks. Skin Cancer Foundation. Updated August 2021. https://www.skincancer.org/risk-factors/uv-radiation/#uvb

3. Ask the expert: Does a high SPF protect my skin better? Skin Cancer Foundation. June 9, 2020. https://www.skincancer.org/blog/ask-the-expert-does-a-high-spf-protect-my-skin-better/

4. Waterproof vs. water-resistant: Knowing the difference in sunscreens. Elta MD Skincare. June 14, 2021. https://live-freely.eltamd.com/life-in-the-sun/waterproof-vs-water-resistant-knowing-the-differencein-sunscreens/

5. Q6. What are the main points of the new Final Rule? Questions and Answers: FDA announces new requirements for over-the-counter (OTC) sunscreen products marketed in the US. US Food & Drug Administration. Updated June 23, 2011. https://www.fda.gov/drugs/understanding-over-counter-medicines/questionsand-answers-fda-announces-new-requirementsover-counter-otc-sunscreen-products-marketedus#Q6_What_are_the_main_points

6. Are chemical sunscreens safe? Center for Surgical Dermatology & Dermatology Associates. https://www.centerforsurgicaldermatology.com/should-i-use-a-chemical-or-physical-sunscreen/

7. Sunscreen: Chemical ingredients and summertime safety. ChemicalSafetyFacts.org. https://www.chemicalsafetyfacts.org/chemistrycontext/sunscreen-summertime-safety

8. Center for Surgical Dermatology & Dermatology Associates. https://www.centerforsurgicaldermatology.com/

9. How to decode sunscreen labels. American Academy of Dermatology. https://www.aad.org/public/everyday-care/sun-protection/shade-clothing-sunscreen/understand-sunscreen-labels

10. Ask the expert: Does sunscreen stay effective after its expiration date? Skin Cancer Foundation. July 31, 2018. https://www.skincancer.org/blog/ask-the-expert-does-a-sunscreen-stay-effective-after-its-expiration-date/

11. Calvo T. Does sunscreen expire? Consumer Reports. August 11, 2021. https://www.consumerreports.org/sunscreens/does-sunscreen-have-an-expirationdate-a3175803160/