The National Academy of Sciences says more research is needed — even as Hawaii moves to tighten its sunscreen laws.

Longstanding assumptions have held that sunscreen is vital to protect people from the sun’s dangerous rays, but it can be bad for the environment when it washes into the ocean.

The National Academy of Sciences says it’s not that simple.

A report released Tuesday said there’s a lack of conclusive data about whether the chemicals in sunscreen are harming marine life. It also cautioned that the environmental concerns as well as the cost and lack of cosmetic appeal of mineral-based sunscreens may have a negative impact on public health by discouraging their use.

“The existing bans on certain UV filters may be considered precautionary in principle, in that they protect the environment against a potential threat now, rather than wait for more data,” according to an overview of the report. “This approach has raised questions, though, about the potential human health implications resulting from reduced availability of some widely used UV filter ingredients.”

The findings come as Hawaii moves to tighten laws aimed at preventing the use of chemical-based sunscreens in favor of mineral-based versions, which have a bad reputation for being nonabsorbent, greasy and leaving a whitish cast in their wake.

A ban on nonmineral sunscreens takes effect in Hawaii and Maui counties on Dec. 1 and Oct. 1, respectively. That follows a landmark statewide ban of oxybenzone and octinoxate sunscreens, which went into effect in January 2021 — something the Hawaii Legislature is also considering strengthening.

Under the new laws, only mineral sunscreens that use zinc oxide and titanium dioxide will be sold on Maui and the Big Island. Violators face a $1,000 fine, which will be used to fund mineral sunscreen dispensers, educational materials and related purposes at beaches. 

With sunscreen-coated tourists returning to Hawaii’s beaches as the coronavirus pandemic recedes, Hawaii County legislators passed the bill as a response to growing concerns over other chemicals used in sunscreens.

“If we know we can do something that might be good for the environment, and there’s a chance  that it will be better for the environment, then  we should,” said  Holeka Goro Inaba, one of the Hawaii County Council members who introduced the bill.

Recent studies showed that avobenzone and octocrylene, two of the most common chemicals in sunscreen after the oxybenzone and octinoxate ban, harm marine life in a similar way.

In fact, the chemicals were almost banned statewide during the 2021 legislative session by a bill introduced by Sen. Mike Gabbard with the help of the Hawaii Reef and Ocean Coalition .

Studies show fish exposed to octocrylene exhibited endocrine disruption, brain deformities in larvae and reproductive toxicity,  according to the nonprofit Center for Biodiversity.

But the National Academy of Sciences, a nongovernmental organization, says that the science on sunscreens is still evolving, and current research is lacking.

“Some toxicity studies exposed organisms to levels of UV filters (sunscreen ingredients) that are higher than have been found in aquatic environments to date or for durations that may or may not occur in the environment,” the report says.

Studies on the effects of sunscreen on ecosystem processes are largely absent as well. Instead, ecosystem effects are mostly presumed based on effects on the species involved in key community and ecosystem functions, the report adds.

The report also points to the challenge of studying corals in their complex and variable marine ecosystems, noting that most observations made on coral-sunscreen interactions took place in laboratories.

“We have to think of everything in terms of risk-benefit,” said Dr. Robert Shapiro, a Hilo-based dermatologist, who is aware of the report’s findings. “We know the benefits for sunscreen. But problem is, we have no idea about the risks.”

The NAS committee recommended as well that the Environmental Protection Agency conduct a risk assessment on all 17 UV filters found in both inorganic (including titanium oxide and zinc oxide) and organic (including oxybenzone and octinoxate) sunscreens and 15 organic compounds.

The committee emphasized how the recommendations are intended to “optimize the identification of sunscreen ingredients” that are effective in preventing skin cancers, acceptable to consumers and are safe for the environment, especially as temperature rise in sea water due to climate change.

Right now, the Food and Drug Administration doesn’t generally recognize any of the chemicals used in sunscreen products a s safe and effective  because of inadequate data to support a safety finding.

The only active ingredients with such a designation are the minerals zinc oxide and titanium dioxide, which comprise mineral sunscreens.

But the FDA is currently updating its list of ingredients generally recognized as safe and effective. Oxybenzone, octinoxate, avobenzone and octocrylene are among the chemicals the FDA is studying to establish a final order for over-the-counter sunscreen.

As for the efficacy of mineral sunscreens, they are just as good at preventing sunburn and more effective at preventing skin cancer than their chemical counterparts. 

Studies show that zinc oxide and titanium dioxide offer a broader spectrum of protection against both UVA and UVB rays. They also provide the same 80 minutes of water-resistant UV protection as chemical sunscreens.

The difference is that mineral sunscreens are thicker and stay on the surface of the skin, while chemical sunscreens get absorbed and are usually cheaper.

Moreover, the report adds, there are concerns that consumers may use less sunscreen due to perceived environmental impacts or restrictions on certain UV filters that reduce availability of consumer-preferred versions.

“We’re trying to get people to use more sunscreen, not less,” said Shapiro.

Inaba, who was aware of the report’s findings, said he doesn’t believe the nonmineral sunscreen bans will prove harmful.

“I don’t agree that banning chemical sunscreens will prevent or discourage people from wearing sunscreen,” he said. “In fact, people might be more inclined to wear sunscreen knowing that everything at the store is safe for the environment.”

Hawaii’s statewide ban appears to have had some success.

Cindi Punihaole, director of the Kahaluu Bay Education Center on Hawaii island, hasn’t seen oxybenzone or octinoxate sunscreens sold in stores since the ban took effect.  But she has seen them on beaches as recently as last month during routine swaps of chemical sunscreen for mineral sunscreen carried out by her organization.

In many cases, beachgoers who purchased the sunscreen on the mainland before flying to Hawaii didn’t know about the ban. A 2019 survey of 162 California and Florida residents reported that only about one-third of respondents said they had heard about Hawaii’s sunscreen ban and few had knowledge about the law’s provisions.

Some airlines have made an effort to educate incoming tourists. Hawaiian Airlines includes information about the sunscreen rules for guests in its informational page labeled “What should I pack for my trip to Hawaii?” and through its pre-arrival Travel Pono video.

But tourists aren’t the only ones to blame. Though banned from stores, Hawaii residents can still buy the banned sunscreens online or out of state.

Clear labeling standards could help enable more reef safe sunscreen choices. Researchers advise against trusting the terms “reef-safe” and “reef-friendly,” as they are largely unregulated, with no concrete standards or specific tests on marine organisms. 

Civil Beat’s coverage of climate change is supported by the Environmental Funders Group of the Hawaii Community Foundation, Marisla Fund of the Hawaii Community Foundation and the Frost Family Foundation.

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