What Is a Reef-Safe Sunscreen?

I get asked frequently what makes our sunscreens at Project Reef truly "Reef Safe." The term "Reef-safe" sunscreen refers to sunscreen products without ingredients that are known to harm coral reefs and marine ecosystems.


However, there isn't a set of criteria for what makes a sunscreen reef safe and what doesn't. Suprising to most people, the FDA doesn't have a regulation for what makes a product reef safe and not.


The best source that the industry points to is Hawaii (Act 104), which bans oxybenzone and octinoxate. These are the most studied chemicals, but the general consensus is that all bezones (chemicals that usually end in 'benzone') cause damage to coral reefs. 


What Sunscreen Ingredients Are NOT Reef Safe

Below are ingredients commonly found in traditional chemical sunscreens that are absorbed into the skin and then wash off into water systems.


If a sunscreen contains any of the ingredients below, it is not considered reef safe by most environmental scientists and conservation groups:


Harmful Chemical UV Filters

  1. 3-Benzylidene camphor

  2. 4-Methylbenzylidene camphor (4-MBC)

  3. Avobenzone

  4. Benzophenone-1

  5. Benzophenone-2

  6. Benzophenone-8

  7. Butylparaben (and other parabens like Methylparaben)

  8. Ensulizole

  9. Homosalate

  10. Microplastics (such as exfoliating beads or plastic spheres)

  11. Nanoparticles (Nano-sized Zinc Oxide or Titanium Dioxide)

  12. Octinoxate (Ethylhexyl Methoxycinnamate)

  13. Octisalate (Ethylhexyl Salicylate)

  14. Octocrylene

  15. Oxybenzone (Benzophenone-3)

  16. PABA (Para-aminobenzoic acid)

  17. Phenoxyethanol (often used as a preservative)

  18. Triclosan


What Makes Sunscreen Reef Safe?

A sunscreen is generally considered reef safe if it meets all of the following criteria:


1. Uses Mineral (Physical) UV Filters


Reef-safe sunscreens rely on non-nano zinc oxide and/or non-nano titanium dioxide as their active ingredients.


These minerals sit on top of the skin and reflect UV rays rather than absorbing them.



  1. Zinc oxide: Broad-spectrum (UVA + UVB)


  2. Titanium dioxide: Strong UVB protection




2. Avoids Nanoparticles


“Non-nano” means the mineral particles are larger than 100 nanometers, preventing them from being absorbed by coral or marine organisms.


Nano-sized particles are small enough to be ingested by coral polyps and plankton, which can disrupt the food chain.


3. Free From Known Reef-Toxic Additives


Reef-safe sunscreens typically avoid:



  1. Parabens

  2. Phthalates

  3. Triclosan

  4. Microplastics

  5. Synthetic fragrances


These additives may not all directly damage coral, but they contribute to marine pollution and ecosystem stress.


4. Water-Resistant, Not Water-Soluble


Paradoxically, water-resistant sunscreens are often better for reefs because less product washes off into the ocean.


Look for sunscreens labeled 40 or 80 minutes water-resistant.


Reef Safe vs. Ocean Safe vs. Marine Safe

These terms are often used interchangeably, but none are legally regulated. We at Project Reef always recommend that customers read the active ingredient lists and determine for themselves what is reef safe.  


Here is how they are typically interpreted:




  1. Reef-safe: Avoids ingredients proven to damage coral reefs, which is generally a safer product for marine environments



  2. Ocean-safe / marine-safe: Broader marketing terms that may or may not meet reef-safe criteria



How to Identify a Truly Reef-Safe Sunscreen

We always recommend buying from brands that sell exclusively reef-safe or mineral-based sunscreens, such as those identified in our reef-safe sunscreen guide. 


Before buying, confirm the following:




  1. Active ingredient: Zinc oxide and/or titanium dioxide only

  2. No oxybenzone or octinoxate


  3. Labeled non-nano

  4. No microplastics or synthetic fragrance

  5. Transparent ingredient disclosure


If a sunscreen does not clearly state “non-nano” or lists chemical UV filters, it should not be considered reef safe.


Are Reef-Safe Sunscreens Effective?

Yes. Modern mineral sunscreens provide excellent broad-spectrum protection and are recommended by many dermatologists, especially for:



  1. Sensitive skin

  2. Children and babies

  3. People with eczema or rosacea


The challenge with mineral-based sunscreens is that they are not absorbed into the skin, which can leave a slight white cast and rub off on clothes. However, advances in formulation have also reduced the heavy white cast historically associated with mineral sunscreens. We are biased, but believe our sunscreens at Project Reef leaves very little, if any, white cast. 


Why Reef-Safe Sunscreen Matters

Coral reefs are already under threat from climate change, warming oceans, and pollution. Sunscreen pollution is one of the few factors individuals can directly control.


Choosing reef-safe sunscreen is a simple behavior change that helps:



  1. Protect marine biodiversity

  2. Preserve coral reefs for future generations

  3. Reduce chemical pollution in waterways


Final Takeaway

Reef-safe sunscreen is not just a marketing term. When defined correctly, it means:



  1. Mineral-based UV protection

  2. Non-nano particles

  3. No reef-toxic chemicals

  4. Environmentally responsible formulation


By understanding what makes sunscreen reef safe, you can protect both your skin and the planet at the same time.