Buying Reef-Safe Sunscreen: What to Look For
Key points
- Hawaii bans the sale of sunscreens containing oxybenzone or octinoxate statewide, and Maui County allows only mineral sunscreens with zinc oxide or titanium dioxide.
- ‘Reef-safe’ is not a regulated term, so a bottle with that claim can still contain ingredients that are restricted or discouraged in Hawaii.
- The reliable check is the active ingredients panel on the back, which lists zinc oxide, titanium dioxide or chemical UV filters by name.
- Mineral sunscreens are considered a better option for aquatic life, though nano-sized zinc oxide and titanium dioxide appear on NOAA’s list of chemicals that can harm marine life.
- UPF clothing, shade between 10 am and 2 pm, and applying sunscreen only on exposed skin all cut the amount that washes into the water.
Sunscreen shopping used to be a two-second decision at the drugstore. Then Hawaii started restricting ingredients, tour operators began enforcing their own rules, and travelers discovered that the phrase on the front of the bottle has no legal definition. The fix is simple: learn which ingredients matter, and read the panel on the back of the bottle.
Why Beach Destinations Restrict Sunscreen
Some vacation spots now treat sunscreen as an environmental issue, not just a personal care one. The National Park Service estimates that 4,000 to 6,000 tons of sunscreen leave swimmers and enter the ocean every year, and that sunscreen-linked bleaching puts roughly one reef in ten around the world at risk.
Sunscreen enters the water in more ways than most travelers expect. It washes off while you swim, and again when you rinse at the shower after the beach. In Hawaii, researchers found that many beach showers do not drain to the sewer system at all; they drain onto the sand and back into coastal waters, and sand in the runoff streams carried concentrations high enough to count as point sources of pollution.
The effects on coral are documented. A 2016 study found that oxybenzone, a filter used in more than 3,500 skin care products worldwide, caused four problems in developing coral: greater susceptibility to bleaching, DNA damage, abnormal skeleton growth and deformities in baby coral. At Hanauma Bay on Oahu, oceanographic models determined that sunscreen pollution from a single day of visitors can persist in the bay for up to 50 hours, so it builds up day after day.
A 2022 National Academy of Sciences review concluded that chemical UV filters can harm aquatic life, including corals, and that mineral sunscreen is a better option for aquatic organisms. Most of the destination rules below are built on that conclusion.
The Ingredients That Matter, Listed on the Back
Flip any bottle over and you will find the active ingredients panel. NOAA identifies these UV filters as chemicals in some sunscreens that can harm marine life:
- Oxybenzone, also called benzophenone-3
- Octinoxate
- Octocrylene
- Benzophenone-1 and benzophenone-8
- OD-PABA
- 4-methylbenzylidene camphor and 3-benzylidene camphor
- Nano-sized titanium dioxide and nano-sized zinc oxide
Oxybenzone and octinoxate are the two most widely recognized names, and they are the two Hawaii’s statewide law targets. Maui’s county ordinance also names octocrylene and homosalate among the petrochemical filters it bans. The lesson is that the well-known pair is not the whole list, so scan the entire panel rather than checking for just two ingredients.
Hawaii’s Rules: Statewide, Maui and the Big Island
Hawaii led the country on this issue, passing the first statewide law restricting sunscreens with ingredients known to harm corals, and its rules are the ones travelers run into most. They are also easy to misread, so here is the breakdown.
| Where | What the rule covers | What it means for your bottle |
|---|---|---|
| Hawaii statewide | Sale and distribution of sunscreens containing oxybenzone or octinoxate, effective January 1, 2021 | Personal use is not restricted, but you cannot count on buying these filters at island shops |
| Maui County | Buying, using or giving out sunscreen without mineral active filters, unless a prescription covers it, since October 1, 2022 | Only zinc oxide, titanium dioxide or both can be the active ingredients |
| Big Island (Hawaii County) | Selling, offering for sale or giving out sunscreen without mineral active filters, unless a prescription covers it | A sales restriction with the same mineral active-ingredient standard |
Three details trip people up. First, the statewide law controls sales, not personal use, so the lotion in your bag is not the problem; replacing it on the islands might be. Second, protected bays and snorkel boat crews often enforce their own rules that go beyond what the statute requires, so a sunscreen that clears the statewide rule can still be turned away before a swim. Third, newer filters do not get a pass. Bemotrizinol, known as BEMT, has been added to the FDA’s list of permitted over-the-counter sunscreen active ingredients, but it is a non-mineral filter, so products using it still fail Maui’s mineral-only rule.
Mineral Versus Chemical Filters in Practice
The dividing line in every rule above is mineral versus chemical. Mineral sunscreens use zinc oxide, titanium dioxide or both as active ingredients; chemical sunscreens use carbon-based UV filters like the ones on NOAA’s list. If a beach trip is still in the planning stage, our guide to choosing an island getaway covers what else to weigh before you book.
Mineral is not automatically perfect. NOAA lists nano-sized titanium dioxide and nano-sized zinc oxide among the chemicals that can harm marine life, and some mineral formulas use those small particles to cut down on the white cast. Non-nano mineral sunscreens sidestep the concern at the cost of a more visible film on the skin. That trade-off, a slight white tint in exchange for fewer environmental question marks, is the main decision you are making.
One practical warning: do not assume a whole brand is compliant. Manufacturers often sell mineral and chemical lines side by side, sometimes in near-identical packaging, so check the panel on the specific product every time.
Front-Label Claims That Do Not Guarantee Anything
“Reef-safe” is not a regulated term. No standard defines it, which means a bottle can carry the claim and still contain ingredients that are restricted or discouraged in Hawaii. “Biodegradable” does not help either; an ingredient that eventually breaks down can still injure coral and other sea life before it does.
Treat every front-label phrase, including “reef-friendly” and “ocean-safe,” as marketing until the back panel says otherwise. If the active ingredients list shows zinc oxide, titanium dioxide or both and nothing else, the product meets the mineral standard Hawaii’s counties use. If it shows any chemical filter, it does not.
Travel tip
Ignore the front of the bottle when you shop. The active ingredients panel on the back is the only part of the label that tells you whether a sunscreen meets Hawaii’s rules.
Application, Water Time and Cutting What Washes Off
Whatever sunscreen you buy, the amount that ends up in the water depends on how you use it. Reapply according to the product’s label, especially after swimming, since sunscreen washes off in the water and again when you rinse. Apply it on exposed skin rather than under clothing.
You can also shrink the load by covering up. A sun shirt or other UPF-rated clothing protects long water days better than sunscreen alone, and shade matters too; NOAA suggests seeking shade between 10 am and 2 pm, when the sun is strongest. Check the tide before your beach day as well, since our article on mistakes to avoid when planning a beach day explains how tides reshape everything from where you set up to when you swim.
If your week includes time on a board, a surf school will bring its own sun and ocean guidance; our first-timer’s guide to taking a surf lesson walks through what to expect.
What to Pack for a Beach Week
The cleanest packing rule, and one that holds across the Hawaiian islands, is to bring a broad-spectrum mineral formula, one with zinc oxide or titanium dioxide as the only listed actives, and to make it your default for the whole trip if Maui is on the itinerary. Add a rash guard or sun shirt for days spent mostly in the water. Buying before you leave also matters because island selection can be limited and prices run high; our guide to the real cost of a beach week in Hawaii covers what else to budget for.
Before you pay for any sunscreen, turn the bottle around and read the active ingredients panel. That one habit settles every claim on the front and makes sure what you pack will work on any beach you visit.
Questions travelers ask
Is sunscreen with oxybenzone illegal to bring to Hawaii?
Hawaii’s statewide law restricts the sale and distribution of sunscreens containing oxybenzone or octinoxate, not personal use. Maui County goes further: it prohibits buying, using or giving away sunscreens without mineral filters unless a prescription covers them.
Does ‘reef-safe’ on the label guarantee anything?
No. It is not a regulated term, and a product labeled reef-safe can still contain ingredients that are restricted or discouraged in Hawaii. Read the active ingredients list on the back instead.
Are mineral sunscreens always the better choice?
Mineral filters are considered a better option for aquatic organisms than chemical UV filters. Still, nano-sized zinc oxide and titanium dioxide appear on NOAA’s list of sunscreen chemicals that can harm marine life, so check whether the formula uses non-nano particles.
What else reduces sunscreen pollution besides the bottle I buy?
Swim shirts and other UPF-rated clothing, shade between 10 am and 2 pm, and applying sunscreen only on exposed skin all lower the amount that ends up in the water.