Sunscreens: Can you trust the environmental claims?

When it comes to buying sunscreen, people care about the environmental impact. In our 2023 Sun Smart survey, 28% of respondents said they are very or extremely concerned about the environmental effects of sunscreen ingredients.

Sunscreen companies have jumped on this consumer concern. When we updated our sunscreens database, we found a number of brands touting claims to persuade you to buy a sunscreen that will help you protect the planet as well as your skin.

The most common claim we found was “reef-safe” or “reef-friendly”. But there’s no regulations about what these claims mean, little consistency in what products use it, and the science about the threat sunscreen poses to the environment is still evolving.

We looked at “reef-safe” claims and asked experts about whether buying a sunscreen with green claims is really better for the environment.

What’s the environmental issue?

For many years, sunscreen ingredients have been seen as an emerging environmental concern, especially in beach areas where they get washed off into the ocean when we swim. Studies have shown these UV filters can have a detrimental effect on marine life, including species such as green algae, mussels, sea urchins, fish and coral reefs.

While most sunscreen ingredients have been detected in our oceans, oxybenzone (also called benzophenone-3) and octinoxate (also called octyl methoxycinnamate) are the ones raising the most concern.

In 2018, sunscreens containing these two ingredients were banned in Hawaii except when being used in prescription-only products. Other regions such as the US Virgin Islands and Palau have similar bans. Thailand has announced a ban of certain ingredients being used in its national parks.

In 2022, the island of Maui took the ban further – prohibiting the use of all sunscreens except those with non-nano mineral actives (zinc oxide and titanium dioxide) unless it’s a prescription product. Nanoparticles are smaller than 100 nanometres and invisible to the human eye – they help mineral sunscreen rub into the skin better and won’t leave you with that pasty look.

What does the science say?

A 2022 report from the US National Academies of Sciences, Engineering and Medicine reviewed the effects of sunscreens in aquatic environments and its implications for human health and usage. It outlined the challenges in determining the effect of UV filters on aquatic environments and gaps in understanding.

Given the evidence that aquatic ecosystems are exposed to UV filters and the importance of UV filters for skin protection, the report recommended the US Environmental Agency should conduct an urgent ecological risk assessment of UV filters.

Experts agree that more research is needed to find answers about the effect of sunscreen ingredients on the environment.

Professor of toxicology at the University of Canterbury Ian Shaw said while there’s better evidence to suggest we don’t buy sunscreens with oxybenzone or octinoxate, more research is needed to determine whether other UV filters are in fact safer.

“Other UV filters have structures which mean they will break down more rapidly in the environment; however they still have worrying molecular groups that resemble the damaging parts of oxybenzone. We just don’t know whether other UV filters are as harmful yet.”

Professor Shaw also pointed out that most of the studies showing harm have been done in the lab at much higher levels than have been detected in our oceans.

It’s also important to put the risk of sunscreen use in perspective. When it comes to harming the environment, including coral reefs, sunscreen ingredients are only one part of a larger issue. Factors such as elevated sea temperatures and sewage and wastewater entering the ocean have been shown to affect our waterways.

Can you trust green claims on sunscreen?

Many sunscreen brands are using green claims like “reef-safe”, “reef-friendly” and “ocean-friendly”, but there’s no standard or official definition about what these terms mean.

A position statement prepared by sunscreen expert John Staton for the Australian Society of Cosmetic Chemists stated that products making “reef-safe” claims varied in the UV filters they contained.

In our database, we found some products making claims don’t contain oxybenzone or octinoxate. Others include only mineral UV filters (zinc oxide and titanium dioxide), while some contain a combination of mineral and chemical actives.

Mr Staton said to truly validate the lack of toxic effect on marine organisms, a number of tests for toxicity and biodegradability needed to be undertaken on specific sunscreens.

“However, consumers can be reassured that water-resistant sunscreens that comply with the mandatory Australian and New Zealand sunscreen standard are inherently more coral reef and aquatic environment-friendly compared with sunscreens that might be made to comply with other sunscreen standards from different countries.”

“Our standard requires that the claimed SPF of a water-resistant sunscreen is based on efficacy tests done after the sunscreen has been used in water on humans. So, in theory, a 2-hour or 4-hour water-resistant product should almost not wash off at all,” said Mr Staton.

Cosmetics NZ general manager Martha Van Arts said the guiding principle for its members is that product claims must be able to be substantiated. “Reef-safe” isn’t a regulated term covered under the Sunscreen Act 2022, Van Arts said so it’s up to individual brands to ensure claim substantiation.

“While a reef-safe claim might resonate with a consumer’s personal values, Cosmetics NZ encourages Kiwis to find a sunscreen they’ll use regularly, alongside other forms of sun protection, to stay safe in New Zealand’s harsh sunshine,” she says.

Dr Louise Reiche, a dermatologist and the past president of the New Zealand Dermatological Society Inc (NZDSI), said it’s a balancing act to protect skin and minimise potential harm to the environment.

“Consider sun protection as a total package. Wear sun protection clothing with good body coverage such as a long-sleeved rash shirt or a wetsuit. This is a good way to cut back on the amount of sunscreen you use.”

Sunscreen tips to protect your skin and ocean

• Cover up with sun protection clothing to use less sunscreen. Think of sunscreen as one part of your sun protection. Wear sun-protective swimwear such as rash shirts and wetsuits. Then you’ll only need to wear sunscreen on exposed areas such as your face and hands.
• Choose a water-resistant sunscreen. Sunscreens tested to the Australian and New Zealand standard have been tested in water conditions.
• Apply early. Make sure you apply it 20 minutes before you go in the water giving it time to form a barrier on your skin.
• Skip the sunscreen spray. Aerosols cause sunscreen particles to fall to the sand where it can be washed into the ocean. The windier the day, the more sunscreen is wasted.