What is the Cyclopentasiloxane and Dimethiconol blend and what is it used for?
This is a multi-component silicone blend (cyclopentasiloxane, dimethiconol, phenyl trimethicone and related silicones) used as a conditioning and slip base in personal care. It provides smoothing, shine and slip in hair serums and leave-on products, a silky emollient after-feel in skin care, and fast, even spreading with reduced tack.
CYCLOPENTASILOXANE- ▸ Hair conditioning: Smoothing, shine, and slip in serums and leave-on products
- ▸ Skin care: Emollient and silky after-feel in lotions and primers
- ▸ Spreading agent: Fast, even spread and reduced tack in formulations
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Request SDS →A formulated cosmetic silicone blend of cyclopentasiloxane (CAS 541-02-6), dimethiconol, phenyl trimethicone, C12-15 alkyl benzoate, and dimethicone crosspolymer. Used as a conditioning, smoothing, and slip-enhancing base in hair- and skin-care formulations. Supplied as a clear fluid.
Reviewed and updated July 2026 by the RawSource technical team.
Cyclopentasiloxane and Dimethiconol Blend is a five-component cosmetic silicone system pairing volatile cyclopentasiloxane (D5) carrier fluid with dimethiconol, phenyl trimethicone, C12-15 alkyl benzoate, and dimethicone crosspolymer.
Key Figures for Buyers
- 0.1% w/w is the EU concentration cap on the D5 carrier under REACH Annex XVII entry 70: wash-off cosmetics since 31 January 2020, all other cosmetic products after 6 June 2027, per Commission Regulation (EU) 2024/1328.
- 3.87 cSt at 25 °C is the typical viscosity of the cyclopentasiloxane (D5) carrier, with 0.959 g/mL density, 76 °C flash point, and 210 °C boiling point, per Gelest product data (accessed 2026).
- 705 cosmetic formulations reported phenyl trimethicone in 2023 FDA VCRP data, 659 of them leave-on, and an industry concentration survey reported leave-on use up to 24.8%, per the CIR final safety assessment (2023).
- Safe at reported concentrations is the EU SCCS verdict on D5 in cosmetics (SCCS/1549/15, final version 29 July 2016), excepting hair styling aerosols and sun care sprays, with D4 impurity to be kept as low as possible.
- 370.77 g/mol is the molecular weight of the D5 component (C10H30O5Si5), per the NIST Chemistry WebBook (accessed 2026); the finished blend is a mixture and carries no single CAS number.
Regulatory restriction status
Cyclopentasiloxane and Dimethiconol Blend (CAS 541-02-6) appears on the regulatory list(s) below. This is public regulatory information about the substance — not a statement about any specific supplier’s material, and not a safety claim. Confirm the current status for your jurisdiction and intended use.
- REACH SVHC Candidate List (EU): listed 27 Jun 2018 on the basis of PBT (Art. 57(d)), vPvB (Art. 57(e)). SVHC status triggers EU supplier-communication and notification duties above 0.1% w/w; it is not, by itself, a ban on sale.
Sources: ECHA Candidate List / Annex XIV / Annex XVII (echa.europa.eu); U.S. EPA TSCA; UN Stockholm Convention / EU POPs Regulation; California OEHHA Proposition 65 list. Retrieved 2026-07-13.
Frequently Asked Questions
What is dimethicone crosspolymer?
Dimethicone crosspolymer is a cross-linked silicone elastomer that thickens silicone phases and contributes a soft, powdery, slip-enhancing feel. In this blend it is combined with cyclopentasiloxane, dimethiconol, phenyl trimethicone, and C12-15 alkyl benzoate to form a conditioning, smoothing base for hair- and skin-care formulations.
What is this cyclopentasiloxane silicone blend used for?
This formulated silicone blend is used as a conditioning, smoothing, and slip-enhancing base in personal care: smoothing, shine, and slip in hair serums and leave-on products; emollient silky after-feel in lotions and primers; and as a fast, even-spreading, low-tack agent in formulations.
What does each component contribute to the blend?
Cyclopentasiloxane (CAS 541-02-6) is the volatile carrier; dimethiconol and phenyl trimethicone add conditioning, shine, and substantivity; C12-15 alkyl benzoate is an emollient ester that boosts spreadability and solubilizes other ingredients; and dimethicone crosspolymer provides a soft, velvety feel and viscosity control.
Is this silicone blend water soluble?
No. It is a silicone-based, oil-phase blend and is not water soluble; it disperses in the oil/silicone phase of an emulsion or is used in anhydrous systems. Consult the product SDS and technical data sheet for compatibility and handling.
How does RawSource supply this blend and at what cost?
RawSource supplies the blend as a clear fluid in industrial quantities for formulators, with a CoA and SDS provided per shipment. Packaging and lot size are confirmed per order, and bulk pricing is quoted per order based on quantity, packaging, and destination. Submit a bulk RFQ for current pricing.
Why is cyclopentasiloxane getting banned?
No ban exists; the EU restricts concentration on environmental grounds. REACH Annex XVII entry 70 caps D4 and D5 at 0.1% by weight in wash-off cosmetics, in force since 31 January 2020, and Regulation (EU) 2024/1328 extends the cap to all other cosmetic products after 6 June 2027. The EU identified D5 as very persistent and very bioaccumulative (vPvB), an environmental classification. Formulations sold into the EU need reformulation plans keyed to those dates.
Is cyclopentasiloxane safe for skin?
The EU Scientific Committee on Consumer Safety concluded that cyclopentasiloxane (D5) in cosmetic products “is safe at the reported concentrations, except for use in hair styling aerosols and sun care spray products” (SCCS/1549/15, 2016). The SCCS also advised keeping the D4 impurity level as low as possible, which makes D4 content a specification point when qualifying suppliers. The EU’s later concentration restriction rests on environmental persistence findings, not on a change in that skin-safety assessment.
Is phenyl trimethicone a carcinogen?
Available evidence does not indicate carcinogenicity. In the 2023 Cosmetic Ingredient Review assessment, phenyl trimethicone was not mutagenic in Ames tests with or without metabolic activation, and the Expert Panel concluded the ingredient is safe in cosmetics at present practices of use, which reach 24.8% in leave-on products. The panel noted no published carcinogenicity studies exist and flagged incidentally inhaled products as the one open data gap.