Sunscreen saves you from painful sunburns and, if you wear it regularly, can cut your risk for melanoma, the deadliest skin cancer, in half according to a 2011 Australian study. But with all the scary headlines about potentially dangerous ingredients, you may be wondering which to slather and which to skip. Here’s what the latest research says about eight common ingredients.

Oxybenzone

Widely used in sunscreens since 1978, oxybenzone was found in 81 percent of sunscreens, cosmetics and other personal care products recently tested by the New York State Department of Health. It protects skin by absorbing the sun’s damaging UV-A and UV-B rays.

The concerns: In lab studies, oxybenzone acted as endocrine disruptor, mimicking the effects of estrogen in the body. Endocrine disrupters are suspected of harming health in a number of possible ways, including lowering fertility and increasing the risk of endometriosis (a painful disorder in women in which tissue that normally lines the uterus grows outside of it) and some cancers.

In a 2012 study from the New York State Department of Health of 625 women who’d had surgery for endometriosis, researchers found that women with the highest levels of a chemical called 2,4OH-BP in their urine had a 65 percent greater risk for endometriosis compared to women with the lowest levels. The chemical occurs when benzophenones, used in cosmetics and sunscreens, break down in the body.Meanwhile, there’s strong evidence oxybenzone is absorbed into the body when applied to the skin. In a 2008 Centers for Disease Control and Prevention (CDC) study, researchers found signs of oxybenzone in 97 percent of urine samples.

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Slather or skip it? Experts disagree. The American Academy of Dermatology (AAD) says oxybenzone is safe: “Available peer-reviewed scientific literature and regulatory assessments from national and international bodies do not support a link between oxybenzone in sunscreen and hormonal alterations, or other significant health issues in humans,” the group notes on its website. The Environmental Working Group (EWG), a consumer advocacy group, evaluated the safety of sunscreen ingredients based on published research and cautions consumers to avoid sunscreens with oxybenzone.

Avobenzone (Parsol 1789)

This sunscreen ingredient, also called Parsol 1789, works by reflecting the sun’s ultraviolet rays. Brown University experts in a 2011 review of sunscreens called it “one of the best sunscreen agents because of its ability to absorb UV light over a very broad spectrum.”

The concerns: Few. The EWG notes that some people may have allergic reactions to avobenzone.

Slather or skip it? Slather. Avobenzone is particularly effective at blocking UV-A rays, according to a review for health professionals on the medical website Medscape. While UV-B rays have long been known to cause sunburn and skin damage that leads to cancer development, UV-A rays were recognized more recently as a cancer threat, too. They penetrate deeper into the skin than UV-B rays, leading to wrinkles but also damaging skin cells called keratinocytes in the deepest part of the skin’s upper layer, where most skin cancers occur, according to the Skin Cancer Foundation.

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Zinc oxide and titanium dioxide

Zinc oxide used to be synonymous with the thick bright-white cream on the noses of lifeguards and surfers. Today manufacturers have shrunk the particles in these ingredients so the products are sheer, or nearly sheer, on the skin. The tiny particles, known as nanoparticles, provide better sun protection than the larger particles of zinc oxide in older sunscreens because they deflect light more effectively, Brown University researchers noted in a 2011 review. Titanium dioxide is also effective at deflecting UV-A and UV-B rays, making it “excellent broad-spectrum UV radiation blocker,” according to the American Cancer Society.

Concerns: Nanoparticles have been shown in some studies to damage cells, but there’s no evidence these they can enter the body through the skin. In a 2010 study from Australia’s Macquarie University, researchers tested blood and urine samples from 20 people who slathered on sunscreen with zinc oxide twice daily for five days. They found less 0.01 percent was absorbed.

Slather or skip it? Slather. The EWG and AAD agree that zinc oxide is a safe, effective sunscreen ingredient. Zinc oxide may be your best choice; it’s more transparent and protects against UV-A rays better than titanium dioxide, the Brown University researchers say.

Ecamsule, Tinosorb and enzacamene

Long used in European sunscreens, ecamsule (a UV-A blocker), enzacamene (a UV-B blocker) and Tinosorb (a UV-/UV-B blocker) may be as good or better than at blocking UV rays than ingredients available in the United States, according to the American Academy of Dermatology.

The concerns: In early 2015, the Food and Drug Administration (FDA) announced it didn’t have enough data to decide whether ecamsule, Tinosorb and enzacamene were safe. But trade groups and the AAD protested, saying these ingredients have long track records in other parts of the world.

“Consumers have used sunscreens with enzacamene and ecamsule safely and effectively across the world, including in Europe, South America, Asia, and the rest of North America. Ecamsule, for example, has been available in European consumer products for over twenty years,” the AAD noted in an April 2015 letter to the FDA.

Research suggests ecamsule is just “minimally absorbed” through the skin, reducing the risk for any health effects, according to a 2015 research review published in the Federal Register. According to the EWG, Tinosorb also appears to be minimally absorbed. But enzacamene, which may be an endocrine disruptor, has shown up in breast milk.

Slather or skip it? You’ll find plenty of advice online suggesting you should snap up sunscreens with these ingredients if you’re traveling outside the U.S. According to the EWG, health concerns for ecamsule and Tinosorb appear to be low.

Retinyl palmitate

This is a form of vitamin A. It doesn’t block or filter the sun, but some manufacturers add it to sunscreens to help keep skin young looking. (Vitamin A derivatives called retinols are a common ingredient in anti-wrinkle creams.)

The concerns: Some lab studies in animals suggest retinyl palmitate may trigger genetic changes and increase the risk for cancerwhen skin is exposed to sunlight. A 2007 FDA test-tube study found that this ingredient generates DNA-damaging free radicals in the presence of UV light. And in a 2012 report from the US government’s National Toxicology Program, researchers found that retinyl palmitate sped development of cancerous lesions and tumors in lab mice exposed to UV light. But the AAD and the Skin Cancer Foundation both say these findings don’t apply to humans. According to the Skin Cancer Foundation, antioxidants in the skin neutralize free radicals generated by retinyl palmitate.

Slather or skip: Decide for yourself whether fighting signs of aging while exposed to the sun is worth any potential risk. The EWG calls the evidence against retinyl palmitate in sunscreens “not definitive” but still “troubling” and recommends that consumers avoid it.

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Sari Harrar is an award-winning health, medicine and science journalist whose work appears in Dr. Oz The Good Life magazine, Good Housekeeping, O--Oprah Magazine, Organic Gardening and other publications.