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Other Ingredients

Octocrylene

Also known as: 2-Ethylhexyl 2-cyano-3,3-diphenylacrylate, OCR, Uvinul N 539

The stabilizer-filter hybrid — UVB absorption plus the molecule that keeps avobenzone alive, with a degradation debate.

  • By IngredientWiki Editorial Team
  • Fact-checked by IngredientWiki Editorial Team
  • Updated 2026-09-26
  • 2 min read

In short

Octocrylene is an organic sunscreen active that plays two roles in American broad-spectrum formulas: it absorbs UVB itself and — more importantly — it photostabilizes avobenzone, the key UVA filter, by quenching its excited state. That dual function made it essential to modern US sunscreens. Its recent controversy is chemical: studies show octocrylene slowly degrades over time into benzophenone, a potential carcinogen, and some batches may already carry it as an impurity — findings that prompted scrutiny though not regulatory bans. It has low sensitization rates and remains a standard, well-regarded filter, with the degradation question as an active area of research.

  • UVB filter + avobenzone photostabilizer (dual role)
  • Essential to many US broad-spectrum systems
  • Slow degradation to benzophenone — active research topic
  • Low sensitization; no regulatory ban

What is Octocrylene?

Octocrylene is the unsung coordinator of American sunscreen chemistry. It filters UVB, but its real value is teamwork: octocrylene catches the UVA filter avobenzone in its excited state and calms it down before it degrades — which is why so many broad-spectrum formulas depend on it. The ingredient's modern footnote is a chemistry puzzle worth understanding: over years of storage, octocrylene itself can slowly break down into benzophenone, a molecule with its own concerns. The finding has not changed regulatory status, but it has sharpened the industry's attention to sunscreen stability science.

Where it comes from

Natural sources

  • Fully synthetic cyanoacrylate-based UV filter, introduced in the 1990s

How it's made

Used at up to 10% in US sunscreens, characteristically paired with avobenzone.

What it does in products

  • UVB absorption
  • Avobenzone photostabilization
  • Water-resistance contribution
  • Broad-spectrum system integrity

Benefits

Keeps UVA protection working

strong evidence

Its photostabilizing role prevents avobenzone degradation — without octocrylene, many US broad-spectrum formulas would lose UVA coverage within an hour of sun exposure.

Own UVB contribution

strong evidence

Adds meaningful UVB absorption and formula water-resistance, supporting overall SPF performance.

Low sensitization

strong evidence

Photoallergy is uncommon, making it one of the better-tolerated organic filters.

Side effects & safety

Contact or photocontact allergy (uncommon)Lower rates than several other organic filters.
Eye stinging with heavy application (uncommon)Common to chemical sunscreens.

Safety considerations

  • No specific restriction; general sunscreen-use guidance applies.
  • None significant.
  • Not for: Confirmed octocrylene allergy

How it's used

In supplements

Not an oral ingredient.

In skincare

Up to 10% in US sunscreens; always in stabilized systems.

Regulatory status

  • FDA-approved OTC sunscreen active (up to 10%); under the same GRASE data review as other US filters.
  • INCI name on cosmetic labels: Octocrylene.
  • Regulated as OTC drug active.

Popular products containing Octocrylene

  • La Roche-Posay Anthelios (US formulas) — Octocrylene-stabilized avobenzone systemsLa Roche-Posay · OTC drug
  • Neutrogena Ultra Sheer (US formulas) — The classic stabilizer pairingNeutrogena · OTC drug
  • EltaMD UV Clear (US formulas) — Octocrylene + zinc oxide hybridEltaMD · OTC drug

Product names and brands are shown for reference and belong to their respective owners.

The stabilizer role

Avobenzone absorbs UVA and becomes energetically unstable, degrading within an hour. Octocrylene accepts that excited energy and dissipates it harmlessly, preserving avobenzone through hours of sun. Without this molecular hand-off, American broad-spectrum sunscreens simply would not hold their claims.

The benzophenone question

2021 research showed octocrylene slowly degrades to benzophenone over storage years, and that some commercial batches already contained it as an impurity. Benzophenone is classified as a possible carcinogen. The findings triggered reformulation scrutiny and ongoing research, but regulators have not restricted octocrylene, and the exposure levels involved are far below occupational thresholds.

Frequently asked questions

Is octocrylene dangerous?

No established human harm; its low sensitization and decades of use support safety. The benzophenone degradation finding is a stability concern under active investigation, not a demonstrated consumer risk.

Why can't sunscreens just use avobenzone alone?

Because bare avobenzone photodegrades within an hour. Octocrylene (or alternative stabilizers/encapsulation) is what makes avobenzone's UVA protection last.

Is octocrylene reef-safe?

It was not included in Hawaii's 2021 ban, and its environmental profile is less studied than oxybenzone's. 'Reef-safe' has no official definition — check product-level claims.

The bottom line

Octocrylene is the quiet stabilizer that makes American broad-spectrum sunscreens work — well tolerated, functionally indispensable, and under scientific scrutiny for a slow degradation reaction.

References

  1. Octocrylene photostabilization of avobenzone. PubMed Central. https://pubmed.ncbi.nlm.nih.gov/29424893/
  2. Octocrylene degradation to benzophenone. Chemical Research in Toxicology. https://pubmed.ncbi.nlm.nih.gov/33648344/
  3. 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