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The bleaching and dying of coral reefs is a global crisis. Coral reefs are one of the most biodiverse and productive ecosystems on earth. Although they only occupy a small fraction of the ocean floor, they are home to a quarter of all marine species. If present rates of destruction are allowed to continue, much of the world's coral reefs will likely disappear over the next 30 years. In addition to global climate change and destructive fishing practices, recent studies confirm that man-made pollutants are having a significant negative impact on coral reefs. Unfortunately, one of these pollutants is sunscreen.

Several common sunscreen ingredients have been identified as toxic to coral. Below is a list of these ingredients and how each one adversely affects coral populations. At the bottom of the page, you'll find references that support the information we've provided and also links to the studies.

Zinc Oxide & Titanium Dioxide

These two sunscreen ingredients are minerals that “block” UV rays instead of absorbing them. Although often touted as reef-safe by some sunscreen manufacturers, recent studies show that these compounds interact in seawater with UV light to produce Hydrogen Peroxide, which has been shown to inhibit phytoplankton growth. Phytoplankton is a vital nutrient for reef inhabitants, including many species of coral. (See Photo).

Benzophenones (BP-2 and Oxybenzone)

Benzophenone is a common ingredient in personal care products. There are two derivatives of benzophenone that are common in sunscreens; benzophenone-2 (BP2) and benzophenone-3 (Oxybenzone).

BP-2 has been an additive in personal-care products since the 1960s as a protector against UV. Research shows that BP-2 causes coral to "bleach" and can induce mutations in coral by damaging their DNA. Currently, BP-2 is not removed from most municipal wastewater treatment facilities.

Recent studies show that Oxybenzone damages coral DNA, causing deformities and inhibiting the coral’s ability to reproduce. It also acts as an endocrine disrupter, causing juvenile coral to encase themselves within their own skeleton, leading to their death and keeping future generations of coral from repopulating.


Like Oxybenzone, Octinoxate absorbs UV radiation. Exposure to Octinoxate can awaken dormant viruses within the algae, causing them to multiply and literally explode—inducing coral bleaching and eventually leading to coral death.


Parabens have been widely used in cosmetics and personal care products since the 1950s. About 85% of these products have them—including many brands of sunscreen. Parabens are a preservative. Recent studies show that butylparaben, in particular, can stimulate viruses found in coral that are normally dormant. “Awakening” these viruses results in rapid reproduction that eventually causes the viruses to burst from their algal host, spilling into the surrounding seawater—potentially spreading the problem to other nearby coral communities.


Zinc Oxide and Titanium Dioxide—

Titanium Dioxide Nanoparticles Toxic to Phytoplankton in Sunlight
Sunscreens as a Source of Hydrogen Peroxide Production in Coastal Waters
NOTE: Copyright law prohibits us posting the full study online, but individuals may purchase it in PDF format at the same URL.

Nano or non-nano particles. Does it matter?
Some sunscreen companies claim that mineral blockers are reef-safe when not used in "nano" particle (very small) form. According to David Sanchez, PhD, author of the study on Hydrogen Peroxide Production in Coastal Waters, "The property to generate H2O2 does not depend on the form but of the crystalline structure. Both nano and non-nano are able to generate H2O2 in seawater. However, TiO2 can crystallize mainly in two forms: Rutile or Anatase. Both are photocatalytic, but Anatase is more photocatalytic."

BP-2 & Oxybenzone—

Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone... and its Environmental Contamination in Hawaii and the U.S. Virgin Islands.
Sunscreen Chemical Threatens Coral Reefs (BP-2 Study)
Sunscreen Chemical in Soaps, Cosmetics and Body Fragrances Threaten Coral Reefs

Octinoxate and Butylparaben—

Sunscreens Cause Coral Bleaching by Promoting Viral Infections, 2008.  

Sunscreen Pollution—Implications and Solutions
An article by C.A. Downs, PhD

How does your sunscreen measure up?
Click the link below to download a comparison chart.