Body & Beauty / Compounds / Octinoxate

Octinoxate on your skin: a safety profile

Moderate risk

(People-specific data is limited; this page draws from human adult context.) Octinoxate (OMC; CAS 5466-77-3) is the world's most-used UV-B filter and has been applied to human skin globally for decades without direct evidence of harm at regulatory concentrations. No carcinogenicity classification from any recognized agency. FDA Category III designation (2019) reflects the need for additional safety characterization — not a determination of harm. Confirmed systemic absorption at high blood concentrations (mean ~258 ng/mL after maximal use) far exceeds FDA's 0.5 ng/mL review threshold, making pharmacokinetic and endocrine safety characterization a regulatory priority. Estrogenic activity documented in vitro and in some in vivo rodent studies; clinical relevance at cosmetic use concentrations in humans remains uncertain. Major dermatological organizations continue recommending sunscreen use (including octinoxate-containing products) given the well-established cancer-preventive benefit against UV radiation (IARC Group 1 carcinogen). Individuals seeking to minimize chemical UV filter exposure may switch to mineral (zinc oxide/titanium dioxide) sunscreens — FDA Category I (GRASE) — without meaningful reduction in UV protection.

What is octinoxate?

The IUPAC name is 2-ethylhexyl (E)-3-(4-methoxyphenyl)prop-2-enoate.

Also known as: 2-ethylhexyl (E)-3-(4-methoxyphenyl)prop-2-enoate, 2-Ethylhexyl p-methoxycinnamate, Parsol MCX, Parsol MOX.

IUPAC name
2-ethylhexyl (E)-3-(4-methoxyphenyl)prop-2-enoate
CAS number
5466-77-3
Molecular formula
C18H26O3
Molecular weight
290.4 g/mol
SMILES
CCCCC(CC)COC(=O)C=CC1=CC=C(C=C1)OC
PubChem CID
5355130

Risk for people

Moderate risk

Octinoxate (OMC; CAS 5466-77-3) is the world's most-used UV-B filter and has been applied to human skin globally for decades without direct evidence of harm at regulatory concentrations. No carcinogenicity classification from any recognized agency. FDA Category III designation (2019) reflects the need for additional safety characterization — not a determination of harm. Confirmed systemic absorption at high blood concentrations (mean ~258 ng/mL after maximal use) far exceeds FDA's 0.5 ng/mL review threshold, making pharmacokinetic and endocrine safety characterization a regulatory priority. Estrogenic activity documented in vitro and in some in vivo rodent studies; clinical relevance at cosmetic use concentrations in humans remains uncertain. Major dermatological organizations continue recommending sunscreen use (including octinoxate-containing products) given the well-established cancer-preventive benefit against UV radiation (IARC Group 1 carcinogen). Individuals seeking to minimize chemical UV filter exposure may switch to mineral (zinc oxide/titanium dioxide) sunscreens — FDA Category I (GRASE) — without meaningful reduction in UV protection.

Regulatory consensus

3 regulatory and scientific bodies have classified Octinoxate. The classifications differ — that's the data.

AgencyYearClassificationNotes
WHO2021no carcinogenicity classification; UV-B sunscreen filter without formal carcinogenicity assessment; FDA Category III (insufficient data for GRASE pending additional safety studies); banned in Hawaii and several other jurisdictions for coral reef toxicity
EPA CTX / Genetox—Genotoxicity: negative (Ames: negative, 0 positive / 2 negative reports)
EPA CTX / Genetox—Genotoxicity: negative (Ames: negative, 0 positive / 2 negative reports)

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter octinoxate

  • Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational Environments — Factories, Warehouses, Transportation vehicles
  • Personal Care — sunscreen, moisturizer with SPF, foundation, lip balm

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Octinoxate:

  • Fragrance-free formulations
    Trade-offs: Consumer preference for scented products
    Relative cost: 1.2-2×
  • Essential oil-based fragrances (with disclosure)
    Trade-offs: Natural does not mean safe — many essential oils are skin sensitizers
    Relative cost: 2-5×

Frequently asked questions

What products contain octinoxate?

Octinoxate appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments); sunscreen (Personal care).

Why do regulators disagree about octinoxate?

Octinoxate has been classified by 3 agencies including WHO, EPA CTX / Genetox, EPA CTX / Genetox, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

See Octinoxate in the body app

Look up products containing octinoxate, compare to alternatives, and explore the full data record.

Open in body View raw API data

Sources (2)
  1. FDA 2019 OTC Sunscreen Proposed Rule: Octinoxate Category III Insufficient GRASE Data; Blood Concentration 258 ng/mL Maximal Use Pharmacokinetics; ERα Estrogenic Activity; Uterotrophic Effect Rat; Additional Safety Data Required (2019) — regulatory
  2. Hawaii Act 104 Reef Safe Sunscreen 2021: Octinoxate Oxybenzone Banned Sale January 1 2021; Coral Bleaching Zooxanthellae Viral Activation 10–100 ppb; Palau Bonaire Maldives Reef Bans; Beach Monitoring UV Filter Contamination (2021) — regulatory

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →