Oc
Octocrylene
OctocryleneSPF filter
A UVB filter that keeps avobenzone stable. A 2021 study found it breaks down into benzophenone as products age; what that means is disputed.
What it does
It absorbs UVB and short UVA, but its bigger job is keeping avobenzone from breaking down in sunlight, so most sunscreens with avobenzone include it. A 2021 study found it breaking down into benzophenone, with more as products age; what that means for daily use is disputed.
The evidence, graded
expert consensusThe two-hour rule is written for time outdoors — that is how the AAD phrases it and how the label's wording is scoped. A desk by a sunlit window is the case people miss: ordinary window glass blocks UVB completely but lets through as much as 74.3% of UVA, so a mid-day reapplication there is a reasonable precaution. No study Drop has read measured filter loss on an indoor day, so the indoor half of this is caution rather than measurement.Duarte 2009 · Photodermatology, Photoimmunology & Photomedicine ↗
moderateOctocrylene breaks down into benzophenone, and the amount rises as a product ages. Benzophenone was found in all 16 octocrylene-containing sunscreens tested and not in the one without it, and its level roughly doubled after accelerated aging. The authors estimate up to 70% of it may be absorbed through skin. What this means for daily use is in dispute; the measurement is not.Downs 2021 · Chemical research in toxicology ↗
expert consensusSCCS/1627/21 (March 2021) weighed the endocrine-disruption concerns. It was of the opinion that octocrylene is safe as a UV filter up to 10%, on its own or in a combined use of sunscreen, face cream, hand cream and lipstick, where a propellant spray is safe only up to 9%. It found the endocrine evidence not conclusive and allergic contact dermatitis cases negligible. Photoallergy to it is strongly related to earlier photoallergy to topical ketoprofen.SCCS 2021 · European Commission SCCS (final opinion, 30-31 March 2021) ↗
emergingA retinoid at night and sunscreen in the morning is not a conflict — the retinoid is long gone by then. The question only arises if both are on the skin at once, in one product or in a daytime routine. There, a mineral sunscreen is the cautious pick, because avobenzone's own photo-instability is measured and nobody has measured the pair together.Wang 2011 · Seminars in Cutaneous Medicine and Surgery ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Pairs worth knowing
Read more
Reading the evidence · 6 minSunscreen for Aging Concerns: What a 4.5-Year Trial ShowedDaily sunscreen slowed visible skin aging in a 4.5-year randomized trial, rare evidence in skincare. What that trial shows, and what it doesn't.How Drop works · 6 minSunscreen Reapplication: Why Every 2 Hours Actually MattersSunscreen wears off faster than most people realize. What happens in those 2 hours, when reapplication matters most, and how to do it over makeup.
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