Sunscreen Ingredients to Avoid: Find Out Why

If there's one thing we can count on, it is that the sun will rise in the east tomorrow and a new day will dawn. But even though the sun is reliable, our information about it isn't. Myths and misinformation about the benefits and the dangers of UV exposure and sunscreen continue to cast a haze on our relationship with the sun.

We're here to shine some light on sun protection and help you choose the sunscreen type that will work best for you.

What does sunscreen do?

Sunscreen products act as physical and chemical UV filters that help block ultraviolet radiation—known as UV rays—from the sun. If this sounds like an important job, it is. While those warm rays of sunshine may feel fine on your face, they don't do your skin any favors. UV rays can cause premature aging and contribute to the development of skin cancers, like melanoma.

Sun damage isn't just skin deep, either. It can also cause inflammation, cellular changes and oxidative stress that weakens the immune system, and those bright rays can also damage your eyes.

So daily use of sunscreen is one of the best and easiest ways to protect your skin's appearance and health. And if you're using a product every day, it's particularly important to choose one that's safe and effective.

What are the different types of sunscreens?

Sunscreens can be mineral (zinc oxide or titanium dioxide) or chemical (such as avobenzone, octinoxate, oxybenzone and others). These ingredients act as UV filters either by physically blocking UV rays, which is how mineral sunscreens work, or by absorbing UV rays and releasing them back out as heat energy, which is the way chemical sunscreens do their job.

Both mineral and chemical sunscreens may have the label "broad spectrum," which means they protect you from radiation from the two main types of ultraviolet rays associated with skin cancer and aging: UVA and UVAB. Many broad-spectrum sunscreens have more than one active ingredient, including ingredients like octisalate, octocrylene and homosalate along with the avobenzone or oxybenzone in their formulas.

What ingredients are potentially harmful in sunscreen?

Most of the active chemical ingredients in sunscreens are under scrutiny, and the Food and Drug Administration has called for more testing. In 2019, the FDA sorted the 16 active ingredients found in most sunscreens into three categories:

• GRASE.

  This acronym stands for "Generally Recognized as Safe and Effective." The mineral sunscreens, namely titanium dioxide and zinc oxide, fall into this category. GRASE sunscreens are physical barriers that sit on top of your skin and are not absorbed into the bloodstream. They are reef-safe, and they protect your skin by reflecting harmful UV light away from your body.

• NOT GRASE.

  When applied topically, para-aminobenzoic acid (PABA), an intermediate in the synthesis of folate by bacteria in the gut, may cause some individuals to have allergic skin reactions. This and trolamine salicylate are no longer allowed as sunscreens.

• Insufficient data to determine GRASE.

  The remaining 12 chemical ingredients, namely oxybenzone (BP-3 or benzophenone-3), octinoxate (OMC or octyl methoxycinnamate), cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octisalate, octocrylene, padimate O, sulisobenzone and avobenzone, fall into this category. This means additional data is needed to show that these sunscreens are GRASE.

Most sunscreens commonly found on shelves (other than mineral-based sunscreens) have at least one of these active ingredients.

Pro tip: To err on the side of caution, stick with GRASE sunscreen ingredients.

What are the dangers of oxybenzone?

If oxybenzone isn't banned, why should we consider avoiding it? Our constant exposure to and high absorption of sunscreen chemicals is raising health concerns, especially because there is not enough safety data for many sunscreen ingredients. Oxybenzone (BP-3) is at the top of the concern list, along with octinoxate (OMC), because studies have linked these chemicals to hormone disruption. This means some studies have suggested that sunscreens with this ingredient potentially could impact fertility, onset of puberty and more.

Additionally, studies have shown BP-3 and other chemical sunscreen ingredients may cause contact dermatitis and allergic reactions. Oxybenzone and octinoxate have also been banned in Hawaii because of their toxic effects on coral reefs and marine life.

Also of concern: oxybenzone also has a high absorption rate. How quickly we absorb chemical sunscreens was shown in a 2019 study that measured the blood concentration of avobenzone, oxybenzone, octocrylene and ecamsule in 24 healthy volunteers. They applied sunscreen on 75% of their skin four times a day during the trial—a level you might reach during a day at the beach if you re-apply sunscreen every 90 minutes or so. All of the tested ingredients exceeded the 0.5 ng/mL threshold limit after just one day. In some formulations (four sunscreens were tested), oxybenzone was recorded in the blood at levels over 200 ng/mL after four days.

That being said, we should emphasize that not all studies have found problems with this sunscreen. In fact, a systematic review of 29 studies found elevated benzophenone-3 levels had no adverse effect on male and female fertility, female reproductive hormone level, adiposity, fetal growth, or children's neurodevelopment or sexual maturation.

However, the association of BP-3 level with thyroid hormones, testosterone levels, kidney function and pubertal timing has been reported and needs further study—which means that if you want to stay on the safe side, you might want to stick with sunscreens that are free of oxybenzone…and fortunately, those options abound.

Should you stop wearing sunscreen?

No, absolutely not! Preclinical evidence has raised concerns about the high systemic absorption of sunscreen ingredients, but no studies have actually linked chemical sunscreen use to harmful effects in humans, aside from skin irritation. The FDA has asked for more testing of sunscreen ingredients that are absorbed into the bloodstream, but it stresses that continued use of sunscreen is an important part of sun safety.

Despite rumors to the contrary, oxybenzone sunscreen use has never been linked to increased cancer risk or other health risks. A person is much more likely to get cancer from sun exposure. However, considering all the preclinical data that shows benzophenone-3 acts as an endocrine disruptor and may be harmful (plus its potential negative effect on coral reefs), it is probably wiser to avoid this particular ingredient—not only in sunscreens, but in cosmetics, fragrances and plastic packaging. A little label-reading will buy you peace of mind.

How to choose the right sunscreen for you

Considering that sunscreen is your first line of defense against harmful UV rays, it is good that we have choices!

Mineral sunscreens are non-comedogenic, which makes them a good choice for acne-prone skin and sensitive skin types. They are also effective immediately upon application—but they need to be reapplied frequently. Many people, though, don't enjoy the thick, pasty consistency of these sunscreens. There are many newer mineral sunscreens with non-nano zinc oxide or titanium dioxide, though, that don't make you look like a ghost. These are a good option for anyone looking to avoid potential endocrine-disrupting chemicals and are better choices to protect marine life and coral reefs.

Chemical sunscreens are usually cheaper than zinc-based sunscreens, and they are unlikely to cause adverse health effects when used occasionally. However, they are detrimental to coral reefs and ocean life, and they are more likely to cause skin irritation in people with sensitive skin. Chemical sunscreens must be absorbed into the skin, so they should be applied 20 minutes before sun exposure to be effective. They also must be reapplied frequently—although not as frequently as mineral sunscreens.

No matter which type of sunscreen you choose, try to choose a cream or lotion instead of a spray so you can avoid breathing it in. Mineral sunscreens, especially, should not be inhaled.

Pro tip: even when it's cloudy, put sunscreen on skin that's not covered by clothing.

Other effective sun protection

Broad-spectrum sunscreens are only one element of a skin-cancer prevention strategy. Here are some other ways to have it made in the shade:

• Seek shelter

  : Another good way to protect yourself from the sun is to shade yourself with physical barriers, such as canopies and umbrellas.

• Suit up

  : Wear sunglasses to protect your eyes and wear hats with wide brims, rash guards and protective clothing that adequately covers your arms and legs.

• Watch the clock

  : Try to avoid being in the sun during peak UV hours (usually 10 a.m. to 2 p.m.).

• Nutrient know-how

  : Consider dietary intake of polypodium leucotomos, niacin and red orange extract. These powerful nutrients can help prevent DNA damage caused by sun exposure, repair damaged DNA, and provide protection that compliments your sunscreen's ability to help protect skin from UVA rays and UVB rays.

• Get enough of the sunshine vitamin

  : A study published in Melanoma Research showed vitamin D's promise for helping to minimize your skin cancer risk.

References

• Matta, M., et al. "Effect of sunscreen application under maximal use conditions on plasma concentration of sunscreen active ingredients: a randomized clinical trial." JAMA. June 2019. https://pubmed.ncbi.nlm.nih.gov/31058986/
• Mustieles, V., et al. "Benzophenone-3: Comprehensive review of the toxicological and human evidence with meta-analysis of human biomonitoring studies."  Environ Int. March 2023. https://pubmed.ncbi.nlm.nih.gov/36805158/
• Suh, S., et al. "The Banned Sunscreen Ingredients and Their Impact on Human Health: A Systematic Review." Int J Dermatol. September 2020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7648445/
• Warshaw, E.M., et al. "Patch Testing With Benzophenone-3 and -4: The North American Contact Dermatitis Group Experience, 2013-2020." Dermatitis. March-April 2023. https://pubmed.ncbi.nlm.nih.gov/36917534/
• "Answers to Your Questions About Sunscreen Ingredients." Asco. April 2022. https://www.cancer.net/blog/2022-04/answers-your-questions-about-sunscreen-ingredients
• "Sunscreen Drug Products for Over-the-Counter Human Use." Federal Register. February 2019. https://www.federalregister.gov/documents/2019/02/26/2019-03019/sunscreen-drug-products-for-over-the-counter-human-use
• "The Trouble with Ingredients in Sunscreens." EWG.org. https://www.ewg.org/sunscreen/report/the-trouble-with-sunscreen-chemicals/