Reef-Safe Sunscreen Checker
Paste a sunscreen's ingredient list to see which of its filters are banned in Hawaii, Maui, the Big Island, the US Virgin Islands, Palau, Guam, Aruba and Thailand's national parks, with the law and date for each, and whether it is mineral-only.
Your sunscreen
Paste the full ingredient list from the bottle or the brand's website, both the Drug Facts actives and the inactive ingredients. Or try , or .
Where it's allowed
How the checker works
It looks for each UV filter and preservative by every name it goes by on a label. Oxybenzone is also benzophenone-3, octinoxate is ethylhexyl or octyl methoxycinnamate, avobenzone is butyl methoxydibenzoylmethane, octisalate is ethylhexyl salicylate, and 4-MBC is 4-methylbenzylidene camphor or enzacamene. It then compares what it finds with the text of each law. Everything runs in your browser.
The laws differ in more than their lists. Hawaii's state law, Hawaii County and Aruba ban selling the sunscreen. Maui County, the US Virgin Islands and Thailand's parks also ban using it, and Palau and Guam stop it at the border. Hawaii's and the Virgin Islands' laws don't cover cosmetics made for the face, such as a tinted moisturizer with SPF.
What the science says
Hawaii's 2018 law cites lab studies linking oxybenzone and octinoxate to coral bleaching, damage to coral larvae and harm to fish. In 2022 the National Academies of Sciences reviewed all 17 UV filters sold in the US, zinc oxide and titanium dioxide included. They found the filters in water, sediment and animal tissue, but few studies of long-term or whole-ecosystem effects and limited toxicity data for marine species. They asked the EPA to run a full ecological risk assessment, and stressed that sunscreen remains important for preventing skin cancer.
So the laws are precautionary. They say what may be sold or used in each place; they don't prove that a given sunscreen harms a given reef. Heat stress from warming seas is still the main cause of mass coral bleaching.
Nano or non-nano?
Zinc oxide and titanium dioxide are sold as fine powders, and some of the particles are smaller than 100 nanometers. None of the laws on this page define or ban nano particles. Maui County's website recommends non-nano minerals, but its ordinance only requires that the active ingredients be zinc oxide or titanium dioxide. In the European Union, an ingredient that counts as a nanomaterial (1 to 100 nm) must be labeled with "(nano)" after its name. The US has no such labeling rule, so "non-nano" on a US bottle is the maker's own claim.
What to pack
A sunscreen whose only active ingredients are zinc oxide or titanium dioxide passes every law listed here. For Palau, also check the inactive list for parabens, phenoxyethanol, triclosan and triclocarban. A rash guard, a hat and shade at midday cut how much sunscreen you need in the first place. Our guide to eco-friendly diving and snorkeling covers the rest of reef etiquette.
Whatever you choose, wear sunscreen. If you have questions about your skin, ask a doctor or pharmacist.
Sources
- Hawaii Act 104 (2018), full text. data.capitol.hawaii.gov
- Maui County, mineral-only sunscreen ordinance. www.mauicounty.gov
- US Virgin Islands Act No. 8185. secure.dlca.vi.gov
- Palau Regulations Prohibiting Reef-Toxic Sunscreens (2020). www.palaugov.pw
- Guam Bill 35-38, as passed. guamlegislature.gov
- Tourism Authority of Thailand, national parks sunscreen ban (Aug. 2021). www.tatnews.org
- National Academies, Review of Fate, Exposure, and Effects of Sunscreens in Aquatic Environments (2022). www.nationalacademies.org
- FDA, questions and answers on its sunscreen actions (updated Sept. 2026). www.fda.gov
- EU Cosmetics Regulation 1223/2009, nanomaterial definition and "(nano)" labeling. eur-lex.europa.eu
Each place in the checker links to the law or report it is based on. Laws checked September 2026.
Questions
Is oxybenzone banned in Hawaii?
Yes. Since January 1, 2021, sunscreen with oxybenzone or octinoxate can't be sold in Hawaii without a prescription. Maui County and Hawaii County go further and allow only zinc oxide and titanium dioxide, so avobenzone, octocrylene, homosalate and octisalate are out there too.
Can I use my own chemical sunscreen in Hawaii?
The state law and Hawaii County's ordinance ban selling it, not using it. Maui County's ordinance, which covers Maui, Molokai and Lanai, also bans using non-mineral sunscreen without a prescription. The simplest answer for any island is to pack a mineral sunscreen.
What does "reef safe" mean on a label?
Nothing official. None of the laws here define "reef safe" or "reef friendly", so the words are the maker's own claim. The ingredient list is what counts: check it here against the place you are going.
Does the FDA say these filters are safe?
The FDA has proposed that zinc oxide and titanium dioxide are generally recognized as safe and effective at up to 25%. For twelve others, including oxybenzone, avobenzone, octocrylene and homosalate, it has asked makers for more data; they are still on sale. In 2026 it added bemotrizinol to its approved list and removed PABA and trolamine salicylate.
Why does Key West show as overturned?
Key West voted in 2019 to ban oxybenzone and octinoxate from 2021, but Florida's SB 172 stopped cities regulating sunscreen from July 1, 2020, before the ban started. Nothing is banned there today.
Is my ingredient list stored?
Only in your own browser, so it is still there next time. Nothing is sent to Lazy Seas.