Sun protection is common, but the products we use are a significant concern for marine environments, particularly coral reefs. The popular term “reef safe” suggests a sunscreen will not harm these ecosystems, yet the phrase is often confusing and lacks a clear, universal definition. Understanding which ingredients are problematic and how they affect marine life allows consumers to make informed choices that protect both their skin and the environment.
Chemicals That Harm Coral Reefs
A number of chemical ultraviolet (UV) filters commonly found in sunscreens are damaging to coral reefs. The two most widely studied and restricted ingredients are Oxybenzone (Benzophenone-3) and Octinoxate (Ethylhexyl Methoxycinnamate). These organic compounds absorb UV radiation but wash off swimmers and accumulate around reef areas. Concerns about these chemicals have led to legislative action in environmentally sensitive regions; for instance, Hawaii banned the sale of sunscreens containing Oxybenzone and Octinoxate starting in 2021. Other chemical filters, such as Octocrylene, Homosalate, and Avobenzone, have also drawn scrutiny due to their potential to disrupt marine life.
How Sunscreen Chemicals Affect Coral Health
The chemicals that wash off into the water impact coral health through several biological pathways. One recognized effect is coral bleaching, which occurs when corals expel the symbiotic algae (zooxanthellae) living in their tissues. This expulsion causes the coral to turn white, lose its primary food source, and become susceptible to disease. These chemical UV filters also interfere with the reproductive cycle of corals. Studies show they can cause deformities in developing larvae and damage their DNA, limiting their ability to settle and grow into new colonies, and some chemicals act as endocrine disruptors, causing abnormal skeletal growth in various marine organisms.
The Lack of a Standardized Definition
The term “reef safe” is currently unregulated by major bodies like the U.S. Food and Drug Administration (FDA) or the Environmental Protection Agency (EPA). This means any manufacturer can place the label on their packaging without meeting a government-mandated standard. Consequently, “reef safe” often functions as a marketing term, contributing to consumer confusion and a practice known as “greenwashing.” Greenwashing occurs when companies misleadingly promote a product as environmentally friendly. Many sunscreens labeled “reef safe” omit only Oxybenzone and Octinoxate but may still contain other harmful chemical UV filters, such as Octocrylene, Homosalate, or Avobenzone, requiring consumers to look beyond the label for assurance.
Choosing Reef-Friendly Alternatives
To ensure a product is genuinely less harmful to coral reefs, consumers should focus on the active ingredients list. The most recommended alternatives are mineral-based sunscreens that contain only Zinc Oxide or Titanium Dioxide. These ingredients work by sitting on the skin’s surface and physically blocking UV rays, rather than absorbing them. Consumers should look for sunscreens that specifically use “non-nano” particle sizes for both Zinc Oxide and Titanium Dioxide. Nanoparticles are smaller than 100 nanometers and can potentially be ingested by corals, leading to cellular damage, while non-nano minerals are larger particles that are less likely to be absorbed by marine life.