“Reef-safe sunscreen” refers to products formulated to minimize harm to marine ecosystems, particularly coral reefs. This term highlights the importance of choosing sun protection that safeguards both human skin and ocean health.
Ingredients Harmful to Coral Reefs
Certain chemical ingredients commonly found in sunscreens pose significant threats to coral reefs. Oxybenzone and octinoxate are two of the most widely recognized chemicals detrimental to corals. These substances can contribute to coral bleaching, a process where corals expel symbiotic algae, turning white and becoming susceptible to disease and death. Research indicates that oxybenzone can also cause DNA damage, deformities in coral larvae, and reproductive issues in corals.
These chemicals enter marine environments when people swim after applying sunscreen, or indirectly through wastewater runoff. An estimated 6,000 to 14,000 metric tons of UV filtering chemicals are released annually into coastal regions with coral reefs. The widespread presence of these chemicals has prompted legislative action in various regions. Hawaii, for instance, banned the sale of sunscreens containing oxybenzone and octinoxate to protect its coral ecosystems. Other ingredients like octocrylene and avobenzone are also under scrutiny for their potential environmental effects, though oxybenzone and octinoxate remain the primary concern.
Key Reef-Safe Ingredients
Sunscreen products considered safer for marine environments typically rely on mineral-based active ingredients. The primary components are zinc oxide and titanium dioxide, which function as physical blockers. These minerals work by sitting on top of the skin, creating a barrier that reflects and scatters ultraviolet (UV) radiation away from the body, rather than absorbing it like chemical filters. This physical mechanism of protection is less harmful to marine life compared to chemical UV filters.
Particle size is a factor in their environmental impact. Non-nano particle sizes for zinc oxide and titanium dioxide are preferred because larger particles are less likely to be ingested by marine organisms or absorbed into their tissues. Sunscreens labeled as “non-nano” indicate that the mineral particles are greater than 100 nanometers in size, reducing potential ecological concerns.
Identifying Truly Reef-Safe Sunscreen
To identify reef-safe sunscreen, check the ingredient label rather than relying solely on marketing claims. Look for active ingredients that are exclusively non-nano zinc oxide and non-nano titanium dioxide. Conversely, ensure the product does not contain oxybenzone or octinoxate, as these are the most commonly identified harmful chemicals. Many products labeled “reef-safe” may still contain other concerning ingredients, highlighting the need for careful label scrutiny.
Beyond active ingredients, consider the product’s form. Lotions are often preferable to spray sunscreens because sprays can release airborne particles that may drift onto sand and then wash into the ocean, contributing to pollution. Physical sun protection, such as rash guards, hats, and sunglasses, offers additional defense. Combining these methods reduces the amount of sunscreen needed, further minimizing environmental impact.