# CYCLOPENTASILOXANE (cyclopentasiloxane) — Global Cosmetic Regulatory & Formulation Monograph

- **Canonical URL**: https://www.inciname.com/en/ingredients/cyclopentasiloxane
- **Standard INCI**: `CYCLOPENTASILOXANE`
- **KR MFDS Standard Name**: `사이클로펜타실록세인`
- **CAS No.**: `541-02-6`
- **EC / EINECS No.**: `208-764-9`
- **Origin**: `synthetic`
- **Functions**: 모발컨디셔닝제, 피부컨디셔닝제, 용제, 에모리엔트
- **Molecular Formula / MW**: `—` (— g/mol)

## 1. 7-Track Official Regulatory Label Names
| Track | Official Label Nomenclature |
| :--- | :--- |
| KR (MFDS Standard) | 사이클로펜타실록세인 |
| KR (Former Names) | 사이클로펜타실록산 |
| EU (CosIng 1223/2009) | CYCLOPENTASILOXANE |
| US (PCPC / MoCRA INCI) | CYCLOPENTASILOXANE |
| US (FDA OTC Monograph) | — |
| CN (NMPA IECIC) | 环五聚二甲基硅氧烷 |
| JP (JCIA / MHLW QD) | シクロペンタシロキサン (QD: デカメチルシクロペンタシロキサン) |

## 2. Layer 1 — Global 6-Region Statutory Summary
- **KR (MFDS)**: `restricted`
- **EU (1223/2009)**: `restricted`
- **US (FDA/MoCRA)**: `none`
- **CN (NMPA IECIC)**: `noted` (Entry: `3031`)
- **JP (MHLW)**: `none`
- **ASEAN (ACD)**: `none`

- **KR** [limited]: ≤ 19.7% —  (화장품 안전기준 등에 관한 규정 [별표2] 사용상의 제한이 필요한 원료)
- **EU** [restricted]: ≤ 0.1% — Commission Regulation (EU) 2024/1328 (REACH Annex XVII): Restricted to < 0.1% in wash-off cosmetics; restricted to < 0.1% in all leave-on cosmetics starting June 6, 2026. (Commission Regulation (EU) 2024/1328)
- **CN** [noted]: — —  (化妆品安全技术规范(2015년판) — 전수 검색)

## 3. Layer 2 — Toxicological & Historical Safe Use Concentrations
- **cn_iecic_max** (leave_on): ≤ 88% — NMPA IECIC (2025) Entry 03067 (2025)
- **cn_iecic_max** (rinse_off): ≤ 40% — NMPA IECIC (2025) Entry 03067 (2025)

## 4. Layer 3 — Formulation Quartiles & Compatibility
- **Optimal pH Window**: 4 – 8
- **Max Process Temp**: ≤ 50°C
- **Synergy Pairings**: GLYCERIN, CAPRYLIC/CAPRIC TRIGLYCERIDE, TOCOPHEROL
- **Incompatibilities**: Verify phase compatibility under extreme pH or high electrolyte loads

## 5. Academic Monograph
■ [1. Chemical Identity & International Labeling Nomenclature]
  - INCI Name: CYCLOPENTASILOXANE | CAS No.: 541-02-6 | EC No.: 208-764-9
  - Origin: SYNTHETIC | Functions: , , , 
  - Physicochemical Profile: Formula      | MW /(Polymer/Complex) | /   | Ionic Nature: non-ionic | CosIng/MFDS 
  - Official Regional Label Names: US [CYCLOPENTASILOXANE] · EU [CYCLOPENTASILOXANE] · CN [环五聚二甲基硅氧烷] · JP [シクロペンタシロキサン] · JP Quasi-Drug [デカメチルシクロペンタシロキサン]
■ [2. Dermatological Mechanism of Action & Functional Role]
  - Cyclopentasiloxane is the cyclic dimethyl polysiloxane that conforms to the formula: Classified under origin 'synthetic', it acts within the cosmetic vehicle or stratum corneum to deliver , , ,  performance and structural formulation stability.
■ [3. Global 6-Jurisdiction Regulatory Status & Safety Limits (Layer 1 & Layer 2)]
  - Regional Summary: KR: RESTRICTED | EU: RESTRICTED | US: NONE | CN: NOTED | JP: NONE | ASEAN: NONE (CN IECIC (2025) Entry No. 3031 (环五聚二甲基硅氧烷))
  - [KR / COMPOSITION / limited] (Max 19.7%): 
  - [CN / COMPOSITION / noted]: 
  - [EU / OFFICIAL / restricted] (Max 0.1%): Commission Regulation (EU) 2024/1328 (REACH Annex XVII): Restricted to < 0.1% in wash-off cosmetics; restricted to < 0.1% in all leave-on co
  - Official Safety & Historical Use Concentration (Layer 2): CN_IECIC_2025 (cn_iecic_max, leave_on): Max 88.0% / CN_IECIC_2025 (cn_iecic_max, rinse_off): Max 40.0%
■ [4. Formulation Dosage Guide by Product Category (Layer 3-A)]
  - [anhydrous_balm] Typical range: 3.0 ~ 44.5% (Median 12.0%, Ref: Global Starter Formulation Library Statistical Distribution (n=5, ELEMENTIS 3 · EVONIK 1 · GRANT 1)) — Anhydrous balm, oil & stick structural emollient
  - [aqueous_serum] Typical range: 1.5 ~ 50.0% (Median 9.2%, Ref: Global Starter Formulation Library Statistical Distribution (n=22, ELEMENTIS 10 · EVONIK 8 · GRANT 4)) — Aqueous serum, toner & hydrogel matrix formulation component
  - [emulsion_cream] Typical range: 1.0 ~ 25.0% (Median 7.0%, Ref: Global Starter Formulation Library Statistical Distribution (n=32, EVONIK 17 · GRANT 14 · ELEMENTIS 1)) — Emulsion cream & lotion structural / conditioning agent
■ [5. Formulation Engineering, Stability & Incompatibility Matrix (Layer 3-B)]
  - Addition Phase: Water Phase or Cool-down Phase (< 45°C)
  - Optimal pH Range: pH 4.0 ~ 8.0 | Max Process Temp: Max 50°C | Electrolyte Tolerance: MEDIUM
  - Incompatibility / Caution: Verify phase compatibility under extreme pH or high electrolyte loads
  - Synergy Pairings: GLYCERIN, CAPRYLIC/CAPRIC TRIGLYCERIDE, TOCOPHEROL | Reference Trade Names: CYCLOPENTASILOXANE
■ [6. Peer-Reviewed Literature & Official Compendia Evidence]
  - PMID 27845160 (2017, Regul Toxicol Pharmacol): Opinion of the Scientific Committee on Consumer Safety (SCCS) - Final version of the opinion on decamethylcyclopentasilo
  - PMID 23857018 (2013, Dermatitis): Compound allergy to a lipophilic gel containing vitamin E acetate and cyclopentasiloxane
  - PMID 23186890 (2013, Chemosphere): Accounting for intended use application in characterizing the contributions of cyclopentasiloxane (D5) to aquatic loadin

## 6. Linked PubMed Literature
- [PMID: 27845160] Opinion of the Scientific Committee on Consumer Safety (SCCS) - Final version of the opinion on decamethylcyclopentasiloxane (cyclopentasiloxane, D5) in cosmetic products — *Regul Toxicol Pharmacol* (2017)
- [PMID: 23857018] Compound allergy to a lipophilic gel containing vitamin E acetate and cyclopentasiloxane — *Dermatitis* (2013)
- [PMID: 23186890] Accounting for intended use application in characterizing the contributions of cyclopentasiloxane (D5) to aquatic loadings following personal care product use: antiperspirants, skin care products and hair care products — *Chemosphere* (2013)
- [PMID: 22247236] Safety assessment of cyclomethicone, cyclotetrasiloxane, cyclopentasiloxane, cyclohexasiloxane, and cycloheptasiloxane — *Int J Toxicol* (2011)
- [PMID: 36161591] Laser therapy for treating hypertrophic and keloid scars — *Cochrane Database Syst Rev* (2022)
- [PMID: 36121393] Factors to control the alignment of surface-treated titanium dioxide powders to maximize performance of sunscreens — *Int J Cosmet Sci* (2023)
- [PMID: 32405550] A Prospective Randomized Double-blind study of silicone gel plus Herbal Extracts Versus Placebo in Pre-sternal hypertrophic scar prevention and amelioration — *Heliyon* (2020)
- [PMID: 31879957] Allergic contact dermatitis to Tinosorb S, Scutellaria baicalensis, and other emerging allergens in cosmetics — *Contact Dermatitis* (2020)
- [PMID: 32104422] Effect of silicone oil on the microstructure, gelation and rheological properties of sorbitan monostearate-sesame oil oleogels — *Asian J Pharm Sci* (2018)
- [PMID: 26809918] Comparing the Efficacy of Commercially Available Insecticide and Dimeticone based Solutions on Head Lice, Pediculus capitis: in vitro Trials — *Turkiye Parazitol Derg* (2015)
- [PMID: 20118631] Study on penetration of titanium dioxide (TiO(2)) nanoparticles into intact and damaged skin in vitro — *J Toxicol Sci* (2010)
- [PMID: 18482015] Protective effect of conditioning agents on Afro-ethnic hair chemically treated with thioglycolate-based straightening emulsion — *J Cosmet Dermatol* (2008)