A quick guide to reef-safe sunscreen

First Employee   Apr 27, 2023

Protecting the planet is something essential to us, especially when it comes to marine life. You may have heard that different types of sunscreen can harm aquatic life and coral reefs but that there are also “reef-safe” kinds that are safe for marine life.

However, finding a “reef-safe” sunscreen that protects our skin from damaging UV rays and is safe for marine life can be tricky. Sometimes, “reef safe” or “coral safe” labels on sunscreen aren’t actually accurate.

In this article, we’ll cover what ingredients to avoid in sunscreen and which ones are safe for marine life, so you can easily decide when buying your next bottle. We’ll also talk about other options for sun protection, what you can do with your existing reef-harming sunscreen products, and how you can help advocate for marine life!

UV Filters on Marine Life

Before we dive in (pun intended), let’s talk about what makes some types of sunscreen unsafe for marine life. Sunscreens contain ultraviolet (UV) filters that protect UV rays from affecting your skin. When you participate in a water activity like snorkeling or scuba diving, the sunscreen can wash off into the ocean and impact marine life. According to a study published in Frontiers of Marine Science, scientists have found these UV filters in the water, sediment, and marine life tissues. As they continue to study the impact of UV filters on marine life, preliminary research has identified that they can:

  • Induce bleaching, deform young coral, or damage DNA
  • Impair photosynthesis and growth for green algae.
  • Deform young mussels, sea urchins, and coral.
  • Accumulate in the tissue of dolphins and transfer chemicals to their offspring.
  • Affect fertility, reproduction, and gender characteristics in fish.

(Source: NOAA’s National Ocean Service)

Harmful Ingredients

According to NOAA’s National Ocean Service, the Journal of the American Academy of Dermatology, and other research, the harmful UV filter ingredients in sunscreen are:

  • Benzophenone-1
  • Benzophenone-8
  • 3-Benzylidene camphor
  • 4-Methylbenzylidene camphor
  • Octinoxate
  • Octocrylene
  • Oxybenzone
  • nano-Titanium dioxide*
  • nano-Zinc oxide*

*Note: if they don't explicitly say “non-nano” or “micro-sized,” you can assume they are nano versions of the mineral, and you should avoid them. Nanoparticles of those ingredients provide a lighter texture, so their containers might be labeled as “sheer” or “clear” since non-nano minerals will be visible.

If this sounds overwhelming, you can quickly scan for words like “benzo,” “oct,” or “oxy.” You can locate these words under “active ingredients” on the bottle.

Shop smart; marketing is tricky.

With the uptick in awareness about sunscreen’s impact on coral reefs, many companies are rebranding their bottles to present a perception of being marine-safe. Some will say on the bottle, “Free of Oxybenzone,” which maybe be accurate, but they could substitute it with “Avobenzone,” which isn’t proven to be marine-safe. Some brands might state “reef safe” when explicitly including the abovementioned chemicals.




Don’t let marketing fool you!

Even though this bottle doesn’t have oxybenzone or octinoxate, it still has ingredients harmful to marine life.











Read the ingredients

The reverse side of the bottle lists ingredients harmful to marine life!




Here’s how to ensure you’re avoiding harmful sunscreens:

Don’t just assume it’s okay when it says “reef safe” or “free of [chemical].”

If shopping online, don’t go by the photos; search (Ctrl+F or Cmd+F) for “active” or “ingredient” to find the list of ingredients and see what the product contains.

Rather than looking to rule out unsafe ones, look proactively for reef-safe options. There are many more unsafe options at large box stores than safe ones.

If this sounds tedious, we get it. So let’s talk about the sunscreens you should be looking for.

Marine-safe Sun protection

According to the non-profit Coral Reef Alliance, the safest sunscreens are biodegradable and made of minerals (not chemicals). They recommend using options with “non-nano” (or “micro-size”) versions of titanium dioxide or zinc oxide. “Non-nano” ingredients mean that the particles are larger than 100 nanometers, which makes them too big to be absorbed into tissues (making it safer for marine life and you!). The Surf Rider Foundation mentions that the bottle might say “micro-sized” instead of “non-nano.” If the ingredients don’t explicitly say “micro-sized” or “non-nano,” you can assume it’s nano-sized and should avoid it.

To recap, look for sunscreens that are:

  • Biodegradable
  • Mineral-based - titanium dioxide, zinc oxide
  • Labeled “non-nano” or “micro-sized.”

Sun protection doesn’t always have to come in the form of a sunscreen lotion. Other terrific options include UPF-blocking clothing (e.g., rashguards, outdoor apparel), hats, and avoiding peak sunlight from 10am-2pm. If those aren’t viable options, wearing marine-safe sunscreen is still OK.

We’ve made it easy for you!

While understanding what to look for helps, you might have little time to scrutinize the bottles at CVS or Target. To simplify things, we carry Stream2Sea sunscreen. Steam2Sea is an organization that specializes in reef-safe, biodegradable sunscreen, hair, and body care products. (They even make a mask defogger that’s marine-friendly!) They’re a women-owned company with a staff of water adventurers, so they understand how important it is to have eco-friendly products that actually work. Before your next dive trip, pick up some marine-safe sunscreen at the shop.

We carry a wide selection of Stream2Sea products that are verified to be reef-safe.

What should you do about your existing sunscreen products?

This is a great question, and we’re also very conscious of not being wasteful. When you can, we recommend finishing up your existing sunscreen when participating in activities where the sunscreen won’t immediately wash off into the watershed. (For example, you want to avoid using it while backpacking, especially if you know there’s a risk of rain.) It’s tricky because some research mentions common water treatment plants have difficulty removing the UV filters from the water. So even a shower could mean the UV filters still end up in our watersheds. We recommend that you do what you can and, moving forward, especially for any water-related activities, you use marine-safe sunscreen.

Help us advocate for marine life!

Hopefully, you’re feeling much more confident about marine-safe sunscreen. If you’re interested in doing more to help our oceans, there are a few things you can do. The easiest is probably letting your friends and family know how simple it is to switch to a safer sunscreen.

If you’d like to get more involved, consider leveling up your environmental awareness with any PADI specialty courses, including the Project AWARE Specialty, Coral Reef Conservation, Underwater Naturalist, AWARE Shark Conservation, and Dive Against Debris® Diver specialty. Check our calendar to see when we’re offering classes!

We typically host Dive Against Debris® clean-up events in the area and on our dive trips. We’d love for you to join us for one, or we’re happy to help mentor you to conduct your own.