Are Reef Safe Sunscreens Marine Friendly?

Are Our Sunscreens Truly Marine Friendly?

Maxiblock sunscreens contain no oxybenzone or octyl methoxy cinnamate, making them reef-safe under Hawaii’s Bill S2571. But does that mean they’re truly marine friendly?

The Hawaii sunscreen bans

Since 2021, Hawaii has banned sunscreens with oxybenzone and octyl methoxy cinnamate after research showed these UV filters could harm marine life, including coral reefs. However, this regulation had little impact on Australia, where these ingredients are rarely used.

Hawaii also introduced a new bill in 2021 proposing to ban two more UV filters—octocrylene and avobenzone—while still allowing zinc oxide. But what does the latest science say?

Latest scientific input

There’s a common belief that inorganic UV filters like zinc oxide are gentler on coral reefs than organic UV filters. However, recent studies from the Centre Scientific de Monaco and Wageningen Marine Research challenge this idea.

These studies indicate that newer organic UV filters may be less toxic to marine life than both older organic UV filters and zinc oxide.

That said, the overall impact of sunscreens on marine ecosystems remains unclear. As Professor Terry Hughes, a leading expert on the Great Barrier Reef, puts it: "People make a long list of bad things that human beings do to coral reefs - I would place sunscreen at number 200".

Why Australian 4-Hour Water-Resistant Sunscreens Are the Best Choice

Australian sunscreens must meet the world’s toughest 4-hour water-resistant standards. This means they’re designed to stay on your skin, not wash off into the water. In contrast, sunscreens with lower resistance—like those meeting US or European standards—are more likely to disperse into the ocean.

The Bottom Line

For true marine-friendliness, choose a sunscreen that stays put. We recommend applying Australian 4-hour water-resistant sunscreens before heading into the water. All Maxiblock sunscreens meet this high standard - except for Maxiblock Face.