Glossary
An examination of the impact of sunscreen chemicals on marine ecosystems and the difference between reef-safe and reef-harmful UV filters. Research has shown that chemical UV filters (oxybenzone, octinoxate) contribute to coral bleaching and damage marine organisms at concentrations found in popular swimming areas.
Oxybenzone (benzophenone-3) and octinoxate (octyl methoxycinnamate), two of the most common chemical UV filters, have been documented to cause coral bleaching, DNA damage in coral larvae, and endocrine disruption in fish and marine invertebrates at concentrations as low as 62 parts per trillion.
Hawaii, Palau, Key West, the U.S. Virgin Islands, and Bonaire have banned sunscreens containing oxybenzone and octinoxate to protect their reef ecosystems. These bans reflect growing scientific consensus about the environmental harm of these chemicals.
Mineral sunscreens using non-nano zinc oxide and non-nano titanium dioxide are considered the most reef-safe UV protection option. These minerals sit on the skin surface and are not absorbed, and their larger particle sizes settle out of water rather than remaining suspended where they could contact marine organisms.
The purest approach: wear UV-protective clothing (rash guards, hats) to minimize the amount of sunscreen needed. When sunscreen is necessary, choose non-nano mineral formulations without oxybenzone, octinoxate, octocrylene, or avobenzone. Several brands are now certified reef-safe.
Non-nano zinc oxide is considered the most reef-safe UV filter currently available. It does not cause coral bleaching in studies at environmentally relevant concentrations. Nano-sized zinc oxide has raised some concerns and is still being studied.
Yes. Mineral sunscreens with zinc oxide and titanium dioxide provide effective broad-spectrum UV protection. They may leave a more visible white cast than chemical sunscreens, but tinted versions are available. The UV protection efficacy is comparable.
UV-protective clothing (UPF-rated rash guards and hats) is the most environmentally friendly option because no chemicals enter the water. When sunscreen is needed, non-nano zinc oxide in a biodegradable base is the most reef-safe topical option.
Keep Learning
Browse hundreds of terms covering honey, beekeeping, and natural skincare.