Oxybenzone
Also known as: Benzophenone-3, BP-3, 2-Hydroxy-4-methoxybenzophenone
The most scrutinized sunscreen active — effective UV filtering, measurable absorption, and the reef-ban debate.
In short
Oxybenzone (benzophenone-3) is a broad-spectrum organic UV filter that absorbs UVB and short UVA, and it has been a mainstay of American sunscreens for decades. Two facts dominate its modern reputation. First, it is absorbed through skin more than most sunscreen actives — detectable in blood and urine after application — though decades of epidemiological study have found no established harm at human exposure levels, and the FDA's 2021 proposal to remove it from GRASE status was about data gaps, not demonstrated risk. Second, it is toxic to coral larvae in laboratory settings, driving Hawaii's 2021 ban and the reef-safe movement. The scientific consensus values sunscreen use above the theoretical risks; the environmental concern has real but debated evidence.
- Broad-spectrum UVB/short-UVA filter since the 1970s
- Higher skin absorption than most sunscreen actives
- FDA: no demonstrated harm; GRASE status under review
- Coral-larval toxicity in labs → Hawaii ban (2021)
What is Oxybenzone?
Oxybenzone is the sunscreen ingredient at the center of two modern debates — and understanding it requires separating them. The absorption debate is about humans: oxybenzone crosses the skin more than other filters, and FDA studies found it in blood at levels above a technical threshold, prompting a regulatory review that found no demonstrated harm but flagged data gaps. The environmental debate is about coral: laboratory studies show larval toxicity, Hawaii banned it, and 'reef-safe' became a market category. Neither debate is as settled as headlines suggest, which makes oxybenzone a case study in risk communication.
Where it comes from
Natural sources
- Fully synthetic benzophenone derivative, used as a sunscreen active since the late 1970s
How it's made
Used at up to 6% in US sunscreens, typically combined with avobenzone and octocrylene.
What it does in products
Benefits
Effective UV protection
strong evidenceDecades of use confirm reliable UVB/short-UVA filtering, with the well-documented public-health benefit of preventing sunburn and skin cancer when used properly.
Avobenzone stabilization
strong evidenceA key stabilizing partner that keeps UVA protection intact in many American broad-spectrum formulas.
No demonstrated human harm
strong evidenceDespite measurable absorption, epidemiological and toxicological reviews have not established adverse effects at real-world exposure levels.
Side effects & safety
Safety considerations
- FDA's ongoing review flagged no specific pregnancy harm; some clinicians advise mineral alternatives during pregnancy out of caution.
- None significant.
- Not for: Confirmed photoallergy to benzophenones
How it's used
In supplements
Not an oral ingredient.
In skincare
Up to 6% in US sunscreens; reapply per label.
Regulatory status
- Approved OTC sunscreen active; FDA's 2021 GRASE review proposed further safety data collection rather than immediate restriction.
- INCI name on cosmetic labels: Benzophenone-3.
- Not a cosmetic ingredient in the usual sense; regulated as OTC drug active.
Popular products containing Oxybenzone
- Banana Boat Sport (some formulations) — Oxybenzone-containing sport sunscreensBanana Boat · OTC drug
- Coppertone Sport (some formulations) — Classic US chemical sunscreenCoppertone · OTC drug
- Many pre-2021 US chemical sunscreens — Reformulating as reef concerns grewVarious · OTC drug
Product names and brands are shown for reference and belong to their respective owners.
The absorption findings
A 2019–2020 FDA study found oxybenzone blood levels after maximal-use application exceeded the agency's toxicological threshold of concern — but the threshold is intentionally conservative, the study conditions exceeded real-world use, and follow-up reviews found no clinical harm. The FDA's response was a request for more data, not a finding of danger.
The reef science
Laboratory studies show oxybenzone damages coral larvae at concentrations far above typical reef-water levels, and epidemiological coral data are contested. Hawaii's 2021 ban reflects a precautionary legislative choice. The practical impact: many brands reformulated with mineral or alternative organic filters, and 'reef-safe' labeling — which has no official US definition — became ubiquitous.
Frequently asked questions
Should I avoid oxybenzone?
The strongest scientific consensus: using any sunscreen beats avoiding one over theoretical risk. If you prefer to avoid oxybenzone, mineral or alternative-organic sunscreens are widely available.
Is oxybenzone an endocrine disruptor?
It has weak estrogenic activity in cell assays, but no human study has demonstrated endocrine effects from sunscreen use — a gap between laboratory signals and clinical reality.
What replaced oxybenzone in 'reef-safe' formulas?
Mineral filters (zinc oxide, titanium dioxide) and newer organic actives — though in the US, avobenzone-centered systems remain dominant.
The bottom line
Oxybenzone is an effective, extensively studied UV filter whose theoretical human risks remain unproven and whose reef concerns have real laboratory — but debated real-world — support.
References
- FDA sunscreen absorption study. JAMA. https://pubmed.ncbi.nlm.nih.gov/31058986/
- Oxybenzone and coral: evidence review. PubMed Central. https://pubmed.ncbi.nlm.nih.gov/33151577/
- Sunscreen active ingredients — FDA. U.S. Food and Drug Administration. https://www.fda.gov/drugs/understanding-over-counter-medicines/sunscreen-how-help-protect-your-skin-sun