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Annex VI Entry 16 08/03/2011

DROMETRIZOLE TRISILOXANE

Phenol, 2-(2H-Benzotriazol-2-yl)-4-Methyl-6-(2-Methyl-3-(1,3,3,3-Tetramethyl-1-(Trimethylsilyl)Oxy)-Disiloxanyl)Propyl

DROMETRIZOLE TRISILOXANE appears in Annex VI as a positive-list UV filter entry for EU cosmetics. Maximum concentration in this record: 15%.

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Permitted UV filter— Annex VI, EU Regulation 1223/2009
Max conc.: 15%
Entry: 16

Chemical identity and properties

PubChem 2D chemical structure for CAS 155633-54-8
CAS 155633-54-8PubChem CID 9848888

Drometrizole trisiloxane

Drometrizole trisiloxane is a photostable UVA and UVB light filter. The compound is a lipophilic benzotriazole derivative marketed as Meroxyl XL by L'Oreal, although sunscreens with drometrizole trisiloxane are currently only approved for use in the EU, Canada, Australia, and Japan, among other countries. Despite being used elsewhere in the world with relatively few reports of adverse reactions, the FDA continues to cite that the existing scientific record is not sufficient to establish the compound as being generally recognized as safe and effective for over-the-counter sunscreen use. — DrugBank

IUPAC name
2-(benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-[methyl-bis(trimethylsilyloxy)silyl]propyl]phenol
Molecular formula
C24H39N3O3Si3
Molecular weight
501.8 g/mol
Exact mass
501.22992172 Da
Topological polar surface area
69.4 Ų
Hydrogen-bond donors
1
Hydrogen-bond acceptors
5
Covalent units
1
Defined stereocentres
0

Also known as

SilatrizoleMexoryl XLOR 10154OR-101542-(2H-1,2,3-benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-(2,2,4,6,6-pentamethyl-3,5-dioxa-2,4,6-trisilaheptan-4-yl)propyl]phenolPhenol, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(2-methyl-3-(1,3,3,3-tetramethyl-1-((trimethylsilyl)oxy)-1-disiloxanyl)propyl)-Phenol, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(2-methyl-3-(1,3,3,3-tetramethyl-1-((trimethylsilyl)oxy)disiloxanyl)propyl)-Phenol, 2-(2H-benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxanyl]propyl]-
16 more reported names
2-(2H-1,2,3-benzotriazol-2-yl)-4-methyl-6-(2-methyl-3-(2,2,4,6,6-pentamethyl-3,5-dioxa-2,4,6-trisilaheptan-4-yl)propyl)phenolRefChem:135828919-634-2Drometrizole trisiloxane [WHO-DD]2-(2H-Benzo[d][1,2,3]triazol-2-yl)-6-(3-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)-2-methylpropyl)-4-methylphenolUNII-HC22845I1XDrometrizole trisiloxane [INCI]2-(2H-Benzo[d][1,2,3]triazol-2-yl)-6-[3-(1,1,1,3,5,5,5-heptamethyltrisiloxan-3-yl)-2-methylpropyl]-4-methylphenolEBC-27246HY-W419643DROMETRIZOLE TRISILOXANE [USP-RS]2-(2h-benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyl]phenolTS-10004DB-091411CS-0539357Drometrizole trisiloxane, analytical standard
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Maximum concentration

15%

INCI glossary name

DROMETRIZOLE TRISILOXANE

Chemical name

Phenol, 2-(2H-Benzotriazol-2-yl)-4-Methyl-6-(2-Methyl-3-(1,3,3,3-Tetramethyl-1-(Trimethylsilyl)Oxy)-Disiloxanyl)Propyl

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

SCCS opinions

  • Opinion on Phenol,2-(2H-benzotriazol-2-yl)-4-methyl-6-(2-methyl-3-(1,1,3,3-tetramethyl-1-(trimethylsilyl)oxy)-disiloxanyl)propyl)

Identified ingredients

Key data

CAS
155633-54-8
EC
—
Annex
VI
Entry number
16

Inventory links for DROMETRIZOLE TRISILOXANE

Direct matches are limited for this record, so nearby entries from Annex VI are shown as well.

Annex VI 13
Nearby record in the same annex

PEG-25 PABA

CAS: 116242-27-4
Annex VI 10
Nearby record in the same annex

OCTOCRYLENE

CAS: 6197-30-4
EC: 228-250-8

What Annex VI means for DROMETRIZOLE TRISILOXANE

DROMETRIZOLE TRISILOXANE is an approved UV filter listed in Annex VI of EU Cosmetics Regulation 1223/2009. Only UV filters included in this positive list may be used to provide UV protection in EU cosmetic products.

The maximum permitted concentration specified in this entry applies to the ready-to-use product. Some UV filters are restricted to specific application types or require label warnings.

This record is linked to 1 CosIng inventory ingredient for name and identifier cross-reference. The page also surfaces 12 related annex records with overlapping identifiers, annex logic or naming patterns.

Compliance checklist

  • Concentration in ready-to-use product must not exceed: 15%
  • Check whether the UV filter is approved for both leave-on and rinse-off applications.

Frequently asked questions

Yes. DROMETRIZOLE TRISILOXANE is listed in Annex VI of EU Cosmetics Regulation 1223/2009 as a permitted UV filter. It may be used at concentrations up to the specified maximum in the ready-to-use product.

CAS 155633-54-8 is the unique numerical identifier assigned to DROMETRIZOLE TRISILOXANE by the Chemical Abstracts Service. In cosmetic compliance work, the CAS number is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports. Multiple EU annex entries may share the same CAS number if the same substance appears under different conditions or in different annexes.

The maximum concentration of 15% applies to the concentration of the substance in the ready-to-use cosmetic product. When the substance is supplied as part of a blend or mixture, the calculation must account for the contribution of all sources in the formulation. The combined concentration must not exceed the stated limit.

Use the INCI Checker tool on this site to paste your full ingredient list (INCI) and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records. This is useful for rapid compliance screening of finished product formulas or raw material declarations.
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Source note for Annex VI record DROMETRIZOLE TRISILOXANE

This page summarizes one Annex VI record for DROMETRIZOLE TRISILOXANE from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.

Use this record page to review Annex VI conditions for DROMETRIZOLE TRISILOXANE, but confirm any final regulatory decision against the current official annex wording and source files.

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