Chemical (organic) UV filterReef research: Limited data

Octisalate

A weak UVB filter found in many 'reef-friendly' chemical formulas. Legal under Hawaii state law.

Banned in

Palau

Also excluded where only mineral sunscreen is allowed

Maui County
Hawaiʻi County

Where it’s restricted

Named in the law or guidance

Location	Status	Since
Palau law text ↗	In force	January 1, 2020

Also not allowed under mineral-only rules

Octisalate isn’t named in these laws, but they allow only mineral (zinc oxide or titanium dioxide) sunscreens, so a product containing it is excluded anyway.

Maui County (Maui, Molokaʻi, Lānaʻi) (in force since October 1, 2022)
Hawaiʻi County (Big Island) (in force since December 1, 2022)

Why it’s regulated

In its 2021 proposed order (OTC000008), the FDA proposed that sunscreens containing octisalate are not GRASE because additional data is needed. The FDA says this proposal is not a conclusion that octisalate is unsafe.

What the reef research says

Stien et al. (2020) exposed the hexacoral Pocillopora damicornis to solar filters, including ethylhexyl salicylate (ES), which the paper's compound table lists under the name octisalate. ES raised one steroid (compound 14) at 50 µg/L and triggered a stress or inflammatory response at 300 µg/L and above. The authors say ES may have caused partial bleaching at 1 mg/L, but this is unconfirmed. Mitchelmore et al. (2019) sampled 19 sites around Oahu, Hawaii, where octisalate ranked second in surface water after homosalate and level with homosalate in coral tissue. The authors describe Oahu surface seawater levels as parts-per-trillion. ES effects were reported in the lab at 50 µg/L.

Sources (4)