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The ecological importance of coral reefs cannot be understated. These fragile marine ecosystems face numerous threats, including climate change, pollution, and overfishing. Surprisingly, even the sunscreen we wear to protect our skin from harmful UV rays has been found to have a detrimental effect on coral reefs. Sunscreen may seem harmless when applied to our bodies, but the chemicals present in many of these products can have devastating consequences for coral reefs.

The two main culprits of sunscreens are oxybenzone and octinoxate, together with minor ingredients such as benzophenone-1, benzophenone-8, OD-PABA, 4-methylbenzylidene camphor, 3-benzylidene camphor and octocrylene.

beach full of people using sunscreen

These compounds are commercialized in regular and even some “reef safe” sunscreen formulations for its UV-absorbing properties and have been found to bleach corals, inhibit their growth, and damage their DNA. To protect these vital marine ecosystems, it is crucial to understand the relationship between sunscreen usage and coral reef decline.

Oxybenzone and octinoxate

Oxybenzone, known as benzophenone-3, is a chemical compound commonly used in many sunscreens and personal care products. It is a UV-filtering agent that helps absorb and block harmful ultraviolet (UV) rays from the sun. This compound primarily protects against UVA rays, which can penetrate deeper into the skin and contribute to skin aging and skin cancer. Oxybenzone also has the potential to cause skin allergies and sensitivities in some individuals and, it may lead to skin irritation, allergic reactions or contact dermatitis.

 

Octinoxate, known as octyl methoxycinnamate or ethylhexyl methoxycinnamate, is also a chemical compound commonly found in many sunscreens, lip balms, moisturizers, and other personal care products that provide sun protection. It is known for its lightweight texture, ease of formulation, and compatibility with various cosmetic ingredients.

 

Octinoxate is primarily used to absorb UVB rays, which are responsible for sunburn and contribute to the development of skin cancer. In addition to its UV-filtering properties, octinoxate is also valued for its ability to enhance the stability and effectiveness of sunscreen formulations and other skin care products. It helps to improve the overall UV protection offered by a sunscreen and is often used in combination with other UV filters such as oxybenzone to achieve broad spectrum protection against both UVA and UVB rays.

Understanding the Connection

Oxybenzone and octinoxate can have serious detrimental effects on coral reefs. When washed off our bodies and into the ocean, these compounds can accumulate on corals and lead to severe consequences for their communities. Research has shown that they are agents to coral bleaching. Its particles can penetrate the coral polyps, forcing the organisms to expel their symbiotic algae zooxanthellae due to stress. This process weakens the coral's ability to resist diseases, feed and impedes its growth and reproduction, causing their unavoidable death.

 

Moreover, oxybenzone can induce deformities in coral larvae, further exacerbating the negative impact on coral reef ecosystems. It also disrupts corals by interfering with the natural processes that allow their reproduction and regeneration. By impairing the ability of coral larvae to settle and establish new colonies, it leads to reduced coral reproduction rates. As a result, the overall potential resilience and recovery of coral reefs are compromised, hindering their long term survival. 

 

On the other hand, octinoxate has been found to have a potential hormonal effect in marine organisms other than coral. It can act as an endocrine disruptor, interfering with the normal functioning of this hormones. This disruption can have far reaching consequences for the reproduction and development of marine life, ultimately impacting the overall health and biodiversity of coral reef ecosystems.

 

Octinoxate also has the ability to persist in the environment and accumulate in aquatic organisms over time. As oxybenzone, it is not biodegradable and can accumulate in the tissues of marine organisms, having a long term impact on their health. This accumulation can occur through direct exposure to products containing octinoxate or through the ingestion of contaminated water or sediments such as algae or, dead or poisoned coral.

 

In addition, this compounds impact on coral reefs extends beyond popular tourist destinations. The chemicals are being found in oceanic environments worldwide due to the extensive use of sunscreen products. The contamination of coastal areas, marine reserves, and even remote reef systems highlights the urgent need for action to minimize the presence of oxybenzone and octinoxate in our oceans. This widespread exposure poses a serious threat to coral reefs globally.

sunscreen bleached coral

Natural UV protection

The good news is that alternatives to harmful sunscreens exist, often referred to as "reef safe" or "coral friendly" sunscreens. These environmentally friendly products use natural and organic ingredients like zinc oxide or titanium dioxide, which provide effective UV protection without the harmful chemicals. They do not contribute to coral reef degradation or harm marine life as chemical sunscreens can. Organic mineral particles are larger and less likely to penetrate corals, minimizing the risk of coral bleaching and other negative impacts on marine ecosystems.

Organic and safe

Zinc oxide is a white, powdery mineral that has been used for centuries in various skin care products. In mineral based sunscreens, it is often used in the form of nanoparticles, that provide effective sun protection without penetrating the deep skin or leaving a visible white residue on the surface. Zinc oxide offers broad spectrum protection, shielding the skin from both UVA and UVB rays. It is known for its excellent safety profile and is suitable for sensitive skin types.​

 

Titanium dioxide is the other mineral commonly used in mineral based sunscreens. Like zinc oxide, it acts as a physical barrier against UV rays. Titanium dioxide also provides broad spectrum protection, particularly against UVB rays. It is a white pigment that helps reflect and scatter UV radiation. Titanium dioxide is often used in combination with zinc oxide to enhance the overall effectiveness of sun protection.

 

Furthermore, modern mineral based sunscreens are less likely to leave any white trace on your skin after application. In most cases, they also contain other natural ingredients such as botanical extracts, oils, antioxidants and natural moisturizers to provide additional skincare benefits.

Natural UV protection for the skin and the reef

Mineral based sunscreens are known for their durability and water resistance. Once applied, the protective layer created by the minerals stays intact for an extended period of time, even during water activities or perspiration. This long lasting effectiveness ensures continuous sun protection, reducing the need for frequent reapplication. It is particularly advantageous for individuals engaged in water sports, outdoor workouts, or extended sun exposure.


Zinc oxide and titanium dioxide work by forming a protective barrier on the skin that reflects and physically blocks and scatters UV rays.

girl applying reef safe sunscreen

Both compounds are also non comedogenic, which means that they do not clog the pores, allowing the skin to breath while providing essential protection. Unlike chemical sunscreens that take time to be effective and absorb UV rays, mineral based sunscreens start working immediately upon application, reducing the risk of sunburn, skin aging, long term skin damage and cancer related to UV rays or chemical compounds.

This type of sunscreens are also known for their gentle and hypoallergenic nature. They are less likely to cause skin irritation or allergic reactions compared to chemical sunscreens, making them suitable for individuals with sensitive skin or those prone to allergies. The inert nature of the mineral ingredients ensures a milder formulation, reducing the risk of adverse effects.

 

Overall, zinc and titanium based sunscreens do not contribute to coral reef degradation or harm marine life in the same way that some chemical sunscreens can. Their nature is organic and their particles are biodegradable, meaning they break down naturally over time, minimizing their impact on the environment.

It is just about a change of habits

Recognizing the urgency of protecting coral reefs from sunscreens´ detrimental effect, several governments and organizations have taken steps to regulate sunscreen usage. In 2021, Hawaii became the first U.S. state to ban the sale of sunscreens containing oxybenzone and octinoxate. In addition, other locations such as the U.S. Virgin Islands and Key West, Florida have taken action to limit the use of sunscreens containing these compounds.

 

While government regulations are vital, individuals can play an essential role in mitigating the impact of sunscreen on coral reefs. One way is by limiting the use of sunscreen altogether, using protective clothing. Another, by educating consumers about the importance of choosing reef safe, eco-friendly options and, supporting brands that prioritize environmental sustainability. It is important to always read the product´s ingredients listed to find out if they contain oxybenzone, octinoxate or any of the other derivatives mentioned above, since there are brands that advertise their products as ”reef safe” while utilizing these compounds in their formulas.

Preserving the health and vitality of coral reefs is a collective responsibility. As we enjoy the sun's warmth and the beauty of our oceans, let us also be mindful of the impact our sunscreen choices can have on these delicate ecosystems. By opting for mineral based alternatives and advocating for sustainable practices, we can ensure that coral reefs continue to thrive, providing a home to countless marine species and protecting our planet's biodiversity. STAY SAFE AND KEEP THEM SAFE, LET´S GO DIVING!

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