Octocrylene
Chemical UV filter and avobenzone stabilizer. Degrades to benzophenone (a potential carcinogen) over time. Use cautiously in pregnancy.
Quick answer
Use octocrylene cautiously during pregnancy. It degrades to benzophenone (a potential carcinogen) over time — particularly in older or heat-exposed sunscreens. Systemic absorption demonstrated. Mineral sunscreen is the safer pregnancy choice.
INCI name
Octocrylene
CAS number
6197-30-4
Also known as
2-Ethylhexyl 2-cyano-3,3-diphenylacrylate, OC, Uvinul N-539
Formula
C24H27NO2
What is Octocrylene?
What octocrylene is
Octocrylene is a chemical UV filter that absorbs short-wavelength UVB and UVA-II radiation. Its primary role in modern sunscreen formulations is as a stabilizer for avobenzone — preventing avobenzone’s rapid photodegradation in sunlight1. So it appears in many sunscreens not as a primary UV filter but as a formulation aid.
Why octocrylene is caution-rated in pregnancy
Two distinct concerns drive the caution rating:
- Degradation to benzophenone. A 2021 study from Albert Einstein College of Medicine found that octocrylene gradually breaks down into benzophenone over time, especially with heat and light exposure. Benzophenone is classified by the International Agency for Research on Cancer (IARC) as “possibly carcinogenic to humans”2. The longer a sunscreen sits on a shelf or in heat, the more benzophenone it contains.
- Systemic absorption. The 2020 FDA Maximal Usage Trial confirmed octocrylene exceeds the 0.5 ng/mL plasma threshold after a single application3.
Octocrylene itself hasn’t been clearly linked to endocrine disruption in the way oxybenzone has — but the benzophenone degradation issue is well-documented, and pregnancy-specific safety data are absent.
Where octocrylene appears
Octocrylene is in most chemical sunscreens that also list avobenzone (which is most of them). Check the OTC drug facts panel:
- Common in “sport” and “water-resistant” sunscreens
- Frequent in “daily face SPF” products
- Not present in pure mineral (zinc oxide / titanium dioxide) sunscreens
Pragmatic guidance
For occasional use of an existing chemical sunscreen with octocrylene during pregnancy: probably fine, but check the expiration date and don’t use products that have been stored in hot conditions for extended periods. For daily use or when buying new: choose a mineral formula with zinc oxide or titanium dioxide4.
When to talk to your OB
If you used a product containing Octocrylene before learning you were pregnant, mention it at your next prenatal visit — but most topical cosmetic exposures are not a cause for panic. For prescription exposures or specific concerns, contact your OB or midwife directly.
Sources
- U.S. National Library of Medicine. Octocrylene. PubChem. View source →
- Downs CA, Diaz-Cruz MS, White WL, et al. (2021). Benzophenone accumulates over time from the degradation of octocrylene in commercial sunscreen products. Chemical Research in Toxicology. View source →
- Matta MK, Florian J, Zusterzeel R, et al. (2020). Effect of sunscreen application on plasma concentration of sunscreen active ingredients. JAMA. View source →
- American College of Obstetricians and Gynecologists. Skin Conditions During Pregnancy. ACOG Patient FAQ 169. View source →