From a legislative point of view, sunscreen isn’t simply sunscreen. Aside from potential carcinogenic ingredients and faulty SPF testing outcomes, formulations containing the chemical filter oxybenzone have been banned in Hawaii, the US Virgin Islands, Key West, Aruba, Bonaire, and Palau.

At last count, according to a study published in the Archives of Environmental Contamination and Toxicology, the ingredient was found in over 3,500 formulations, resulting in 6,000-14,000 tons of sunscreen in coral reefs per annum. In its 2021 Guide to Sunscreens, the EWG states oxybenzone is found in 40% of non-mineral sunscreen formulations, a 20% decrease from 2019. The mineral, reef-safe sunscreen category is predicted to have a 5% CAGR between now and 2030, with a global worth of $1.8 billion.

Oxybenzone alters the DNA of the coral, causing it to become encased in its own skeleton and die off. 70-90% of all coral reefs will be lost over the next 20 years. These effects can happen with concentrations as low as 62 parts per trillion. Concentrations in popular tourist areas like the Caribbean and Hawaii were 12 times higher on average. The EWG lists the risks for humans as moderate endocrine disruption, low developmental and reingredientive toxicity, as well as low cancer risk and non-reproductive organ toxicity. But it’s not all about oxybenzone. “Just because a sunscreen contains no oxybenzone or octinoxate doesn’t mean that it is completely nontoxic and harmless to coral reefs and ocean health. Other ingredients such as octocrylene, homosalate, and octisalate can also be harmful to reefs,” states Lea d’Auriol, founder and Executive Director of nonprofit Oceanic Global.

Aside from the marine wildlife and coastline protection that would die away with the reefs, their destruction could also cause a loss of $375 billion annually for local economies. The reef-safe sunscreen category entails formulations that rely on the mineral filters titanium dioxide and zinc oxide, although zinc oxide has also been shown to cause severe coral bleaching due to nanoparticles. According to Spate NYC, average monthly searches for the term “oxybenzone sunscreen” and “reef safe sunscreen” grew by 25.9% and 63.3% in the last year respectively, with 7K searches for the former and 39.3K searches for the latter, and In response, brands such as Coola and Solésence Beauty Science have developed non-nanoparticle formulations.

Solésence Beauty Science has been championing mineral formulations since the company’s onset. “Our foundation has always been our mission, which is to enhance lives through healthy skin. Intrinsic to this mission, in our view, is making mineral-based  finished formulas—which are widely believed to be safe and effective UV protection, and the ‘reef-friendliest’ sunscreen option—accessible to all people,” comments Kevin Cureton, Chief Operating Officer.” Commenting on the brand’s decision to use non-nanoparticle zinc oxide in light of presumed reef-safe mineral formulas with regular zinc oxide still negatively affecting marine wildlife, Dr Harry Sarkas, Chief Scientific Officer states: “The error can be to optimize to one feature or need without addressing others—the point is to make SPF products safe and effective for humans and the environment, but also keep them desirable to use so that they really get used and humans become protected. Beyond that, the science is ever-evolving and complicated—and one barrier is that the results of some studies are not broadly applicable.” Dr. Sarkas adds that “studies that focus on certain particles themselves are not analogous to what the results would be of the surface-treated forms used in the industry.”

How much are sunscreens affecting coral reef destruction compared to other environmental factors? “Around the world reefs are severely affected by global warming-aggravated coral bleaching, agricultural runoff and human development. The impact of sunscreen wash-off has so far shown to be localized and impacts are likely to be restricted to inshore enclosed reef areas and high use dive zones visited by tourist groups,” writes John Staton of the Australian Society of the Cosmetic Chemists Technical Committee.

Furthermore “plastics, textiles, paints, wastewater effluent, and overland runoff” are other materials in the water that contain UV filters, according to a review that calls for more in-depth research on the effects of oxybenzone on coral reef life, while also pointing to the highly lipophilic (read likely to dissolve in fats rather than water like its hydrophilic counterparts) nature of UV filters. The National Academy of Science is currently evaluating all published work and data to hopefully come to a more conclusive outcome. Media coverage of the review states “while sunscreen ingredients are commonly found in ocean water, they may not collect at levels great enough to actually harm coral.”

Journalist Jyoti Madhusoodanan writes: “Coral-bleaching events on Australia’s Great Barrier Reef, for example, have been linked more closely to trends in water temperature than to shifts in tourist activity,” and according to marine biologist Terry Hughes, “the greatest threats to reefs remain rising temperatures, coastal pollution and overfishing. Changing sunscreens might not do much to protect coral reefs. It’s ironic that people will change their sunscreens and fly from New York to Miami to go to the beach. Most tourists are happy to use a different brand of sunscreen, but not to fly less and reduce carbon emissions.”

Nonetheless, reef-safe sunscreens are still proving a popular option for eco-minded consumers. Globally, Google searches for reef-safe sunscreen have quadrupled in the last five years. The term itself, however, is not regulated, and Bondi Sands is facing a class-action lawsuit in the US after labeling products as “reef safe that contained chemical filters. In response, the company stated its formulations are compliant with Australian safety regulations. “It’s important to know that the term ‘Reef Friendly’ is not defined or regulated by authorities, so when you see these words on Bondi Sands sunscreens, it simply means that our entire Suncare range has been formulated in compliance with Hawaii’s regulations and is free of oxybenzone and octinoxate,” the company states on its website. For brands and manufacturers, having a defined and universal standard for the term “reef safe” would be of utmost benefits. It would also aid in ingredient transparency for consumers. “The FDA’s legal reach does not apply to the environment—that is EPA [Environmental Protection Agency] territory on a federal level. As a result, they do not currently have any assessment or regulation in place for reef-safe claims,” Cureton comments, noting that local jurisdictions in heavily impacted areas are addressing emerging concerns.

However, taking a harder look at the term unearths a slightly hazy territory. “Unfortunately, despite several cosmetic products and sunscreens available in the market are defined ‘reef-safe’ or ‘eco-friendly’ or ‘biodegradable,’ they are not so, and indeed lack specific tests on marine organisms,” states marine ecology researcher, Cinzia Corinaldesi. While we can’t forgo sunscreen altogether, hopefully the industry can invest in further testing to determine specifics about  sunscreen filter impacts in order to offer consumers the least environmentally taxing, reef-safe sunscreen option.

“Sharing the science-backed information on why you chose the ingredients and how they work within the formula can help consumers as they struggle through determining what’s best for themselves and their family. Solving the confusion over what ingredients are and what they do is step one in consumer safety. We’re seeing brands and retailers go beyond clarifying key ingredients, and leaning into 360 ingredient storytelling,” Sabrina Noorani, founder of ingredient SaaS platform ClearForMe, tells BeautyMatter, noting that “lightweight Korean and Japanese sunscreen formulations as the most in demand, which are typically more milk and skincare rooted formulas.”

Ecological impact debates aside, it’s evident that fear around the general safety of chemical sunscreens (justified or not) are causing many consumers to reach for mineral options instead. What the reef impact of sunscreen formulations has also brought to light is not just the continuing need for ingredient testing, safety, and transparency, but an imminent need for tackling climate change. And that goes far beyond sunscreen.