Humans need sunscreen to protect their skin from ultraviolet rays and prevent skin cancer. However, researchers recently concluded that chemicals found in all commercially available sunscreens, even reef-safe sunscreen, pose serious threats to the environment, particularly coral reefs, and marine organisms. This begs the question, are reef-safe sunscreen possible? And how can consumers look for the best environment-safe sunscreen? 

In 2008, evidence was found that common ingredients in sunscreen can bleach coral reefs. Sunscreen manufacturers responded to this discovery by creating ‘reef safe’ sunscreens, using alternative UV filters like zinc oxide. However, recent research shows that these options are no safer for the environment.

Why is Sunscreen Bad for the Environment?

During recreational activities and water sports in natural waters, sunscreen washes off people’s skin to disperse in the surrounding environment. Some chemicals in the lotion can be absorbed through the skin and detected in urine within 30 minutes of application. Thus, they enter sewers or septic tanks when people flush the toilet or wash off sunscreen in the shower. In towns near bodies of water without sophisticated sewage treatment and water management systems, sunscreen pollution is inevitable.

There are two kinds of sunscreen available in stores. They work in different ways, but the active ingredients in both types harm the environment.

Chemical (organic): Chemical sunscreens are the most commonly used sunscreen. They absorb and reduce UV rays’ ability to penetrate the skin. 

Their most common active ingredients – oxybenzone, butylparaben, and octinoxate – were identified as environmentally harmful in a 2008 study. Researchers found that the chemicals can activate latent viral infections in the symbiotic microalgae that the corals rely on for nutrition. Studies that followed further demonstrated chemical sunscreen’s harmful impact on coral reefs and marine organisms. According to a 2015 study, “we found that oxybenzone induces coral bleaching by lowering the temperature at which corals will bleach when exposed to prolonged heat stress. We also showed that oxybenzone is genotoxic, meaning that it damages coral DNA as well as induces severe and lethal deformities. Most alarmingly, we determined that oxybenzone also acts as an endocrine disruptor.”

Physical (mineral or inorganic): The second type, often marketed as ‘environmentally-friendly’ and ‘reef safe’, is still less popular than chemical sunscreens. Physical sunscreens block or reflect both UVA and UVB rays but leave a whitish tinge on people’s skin and are often oily and difficult to rub in. 

The most common ingredients in physical sunscreens are zinc oxide and titanium dioxide. A recently published study found that non-coated zinc oxide and titanium dioxide nanoparticles (less than 35 nanometers in diameter), in other words, so-called reef-safe sunscreen, can be toxic to corals, fish, and other reef organisms. Their small size, interaction with cells, and the fact that they cause oxidative stress in sunlight (coral bleaching) damages hard corals and their symbiotic algae.

Sunscreen Overall: Aside from the primary, active ingredients, many other chemicals in sunscreen are potentially toxic to aquatic ecosystems. Methoxycinnamate and camphor are on the International Chemical Secretariat’s SIN (Substitute it Now) list due to their activity as endocrine disruptors to humans and wildlife. Plant-based oils can be toxic to reef organisms as well. Chrysanthemum oil contains Pyrethrins, which are highly toxic to marine species. Neem, eucalyptus, and lavender oils are used as insect repellents or insecticides, suggesting they may also be toxic to invertebrates. Ultimately, organic ingredients are not necessarily safe. 

Are There Any Environmentally and Reef-Safe Sunscreen?

Despite numerous studies indicating that the primary active ingredients in chemical and physical sunscreens damage marine environments, some experts argue that further research is needed. They postulate that studies undertaken in lab environments may fail to capture conditions on the reef, where pollutants are quickly dispersed and diluted. However, while the concentrations of sunscreen ingredients used in some research may be higher than those in natural environments, the negative impact of these chemicals on aquatic organisms is unmistakable. 

Considering this, consumers might feel discouraged in their effort to protect their skin and the environment simultaneously. Yet there is hope for the future; scientists are working on various solutions. For instance, at the College of Pharmacy at the University of Florida, a team is developing a sunscreen using shinorine (a UV-absorbing ingredient harvested from algae).

In the meantime, the following rules of thumb will help consumers choose the most environmentally and reef-safe sunscreen available. 

There are several non-nano zinc oxide-based physical sunscreens that satisfy most, if not all, of these guidelines available.  Raw Love Sunscreen uses 100% plant-based ingredients produced organically. The slightly oily consistency and slight white skin tint upon application may deter some consumers, while the short list of easily recognisable natural ingredients attracts others. Another option, Hello Bello’s Sunscreen Mineral Lotion, is sold in a plastic tube. But the lotion’s scent and texture are similar to that of commonly used chemical sunscreens, making it an easier transition into non-nano zinc oxide-based sunscreens than other options. Last but not least, Raw Elements Sunscreen’s ingredient list does not include any overtly toxic plant-based oils, the container is a recyclable/reusable tin, and the packaging is plastic-free.

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