<!-- Sulisobenzone: is it reef safe? | Reef Label -->
Source: https://reeflabel.com/ingredients/sulisobenzone/

Chemical (organic) UV filter · Reef research: Limited data

# Sulisobenzone

A benzophenone-family filter. Also used in small amounts in cosmetics to protect product color, where it appears in the inactive list.

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](https://reeflabel.com/locations/palau/) [law text ↗](https://www.palaugov.pw/wp-content/uploads/2018/10/RPPL-No.-10-30-re.-The-Responsible-Tourism-Education-Act-of-2018.pdf) | In force | January 1, 2020 |

### Also not allowed under mineral-only rules

Sulisobenzone 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)](https://reeflabel.com/locations/maui-county/) (in force since October 1, 2022)
-   [Hawaiʻi County (Big Island)](https://reeflabel.com/locations/hawaii-county/) (in force since December 1, 2022)

## Why it’s regulated

In the US, FDA's 2021 proposed order (OTC000008) carries over the substance of its 2019 proposal and treats sulisobenzone as not GRASE because the public record lacks enough safety data; FDA says this is not a conclusion that the ingredient is unsafe, and it has not yet finalized the proposal. The EU caps sulisobenzone at 5% in sunscreen.

## What the reef research says

The coral study found for sulisobenzone (BP-4) is He et al. 2019, which tested four benzophenone filters on larvae and adults of two coral species, Pocillopora damicornis and Seriatopora caliendrum, at 0.1–1000 μg/L. None of the compounds tested affected P. damicornis larvae at the concentrations tested. The authors' risk assessment named BP-3, BP-1 and BP-8 as high or medium risk to corals, and BP-4 was not among them. The EU's SCCS opinion, dated 27 March 2024, states that it did not assess the environmental safety of benzophenone-4.

Sources (4)

-   [He et al. 2019, Science of the Total Environment 651: 2391-2399, 'Comparative toxicities of four benzophenone ultraviolet filters to two life stages of two coral species' (DOI 10.1016/j.scitotenv.2018.10.148; abstract read via PubMed 30336428)](https://pubmed.ncbi.nlm.nih.gov/30336428/)
-   [SCCS Final Opinion on benzophenone-4 (CAS 4065-45-6), SCCS/1660/23, final version 27 March 2024](https://health.ec.europa.eu/document/download/3784d1dc-0a4b-4177-ac2c-0a426f68de7d_en?filename=sccs_o_283.pdf)
-   [FDA: Questions and answers on FDA's regulatory actions on over-the-counter sunscreen](https://www.fda.gov/drugs/understanding-over-counter-medicines/questions-and-answers-fdas-regulatory-actions-over-counter-sunscreen)
-   [21 CFR 352.10, Sunscreen active ingredients (eCFR; ensulizole, meradimate, octinoxate and octisalate appear under their revised names in the stayed 2002 amendment)](https://www.ecfr.gov/current/title-21/section-352.10)

**Related ingredients:** [Oxybenzone](https://reeflabel.com/ingredients/oxybenzone/), [Dioxybenzone](https://reeflabel.com/ingredients/dioxybenzone/)

Last reviewed October 14, 2026.

### Label names we match

-   sulisobenzone
-   benzophenone-4
-   benzophenone 4
-   bp-4

### Regulatory status

**Wikidata:** [Q7636301](https://www.wikidata.org/wiki/Q7636301)

**US FDA:** Insufficient data: not GRASE under FDA's 2019 proposal, restated in its 2021 proposed order (OTC000008), until more safety data are submitted. Still a proposal as of September 2026. Max 10% in the US.

**EU:** Approved, max 5%.

**Protects against:** UVB and UVA-II.
