Cyclohexasiloxane

Also known as: Cyclohexasiloxane, 2,2,4,4,6,6,8,8,10,10,12,12-dodecamethyl-, Cyclohexasiloxane, dodecamethyl-, 2,2,4,4,6,6,8,8,10,10,12,12-Dodecamethylcyclohexasiloxane, EINECS 208-762-8, UNII-XHK3U310BA (+9 more)

INCI: CYCLOHEXASILOXANE

Cyclohexasiloxane (CAS 540-97-6) is a cosmetic cosmetic ingredient functioning as solvent, emollient, volatile carrier. NOAEL 1000 mg/kg bw/day (cross-referenced against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: restricted, max ≥0.1% w/w prohibited in all consumer and professional products under EU Reg 2024/1328; enforcement June 6, 2026. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety data.

View industrial chemical safety profile for CAS 540-97-6 →

Auto-generated CPSR Part A draft with source citations
Function
solvent, emollient, volatile carrier
Safety Rating
MODERATE

Chemistry & Identifiers

EC Number
208-762-8

Regulatory Status

EU EU Status restricted
EU Max Conc. ≥0.1% w/w prohibited in all consumer and professional products under EU Reg 2024/1328; enforcement June 6, 2026
US US Status permitted
US Notes No FDA restriction; no US restriction as of 2026

For full compliance data across multiple jurisdictions, use the Substance Compliance tool.

Safety Data

Margin of Safety, dermal absorption, and sensitization profile summaries for Cyclohexasiloxane.

Calculate MoS for your specific formulation with the MoS Calculator.

Pre-Calculated Safety Assessment

Pre-calculated NOAEL → SED → MoS audit trail for Cyclohexasiloxane across SCCS product categories, with measured dermal absorption where available.

EPA ToxValDB — Toxicity Values

2 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).

Endpoint Value Species Route Duration Source
LEL =545.922 mg/m3 Rat inhalation short-term EPA TSCA 8e
LD50 >50000 mg/kg Rat oral - ChemIDplus

Endocrine Disruptor Evidence (Expanded)

Cross-referenced EDC classifications, mechanism data, and dose-response evidence from EDLists, SIN List, and cosmetic-specific detail sources.

Cosmetic-Specific Mechanism
Category: other
Receptor targets: ERα (weak)
LOEC: N/A
EU status: under_review

weak agonist

ECHA REACH Registration

European Chemicals Agency REACH dossier and Substances of Very High Concern listing.

Registration Type
Full
Tonnage Band
1,000 - 10,000 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
Yes (since 27-Jun-2018)
Hazard classification: Restricted (Annex XVII)
SVHC reason: PBT (Article 57d)
Substance of Very High Concern (SVHC)
Included: 27-Jun-2018
PBT (Article 57d); vPvB (Article 57e)

Expanded Jurisdictional Detail

Additional regulatory detail beyond the 7-jurisdiction summary: Saudi SFDA, Korea MFDS, ASEAN ACD, Japan/Korea, Brazil/India, and cross-jurisdictional restriction entries.

Additional Jurisdictional Restrictions (1)
Jurisdiction Status Max % Product Type
UK restricted - -

Typical Use Concentrations

Reported concentration ranges per product category from SCCS/CIR/industry sources.

Product Category Typical Range Max Reported Source
Foundation 2–10 20 CIR

Additional Ingredient Properties

10 property records from structured ingredient metadata.

baby_pediatric
{"cas_number": "540-97-6", "ingredient_class": "other", "pediatric_safety_rating": "good", "minimum_age_months": "3", "neonatal_safe": "no", "premature_infant_safe": "insufficient_data", "skin_barrier_maturity_consideration": "D6 silicone - EU restrictions", "transepidermal_absorption_risk_pediatric": "very_low", "dose_per_kg_body_weight_concern": "Non-absorbed polymer", "skin_surface_area_to_weig…
comedogenicity_detail
{"comedogenicity_rating": "0", "irritancy_rating": "0", "skin_type_suitability": "all,oily,combination,normal,acne-prone", "acne_safe": "yes", "source": "Volatile silicone"}
concentration
{"min_concentration_pct": "5.0", "max_concentration_pct": "30.0", "typical_concentration_pct": "15.0", "product_type": "Primer", "function_at_concentration": "Smoothing", "source": "CIR Safety Assessment"}
deodorant
{"cas_number": "540-97-6", "ingredient_class": "other", "mechanism_of_action": "other", "antiperspirant_efficacy_sweat_reduction_pct": "0", "deodorant_efficacy_hours": "0", "odor_reduction_pct": "0", "bacteriostatic": "no", "bactericidal": "no", "microbiome_impact": "neutral", "axillary_microbiome_effect": "varies by ingredient", "MIC_value_if_antimicrobial": "varies", "astringency_level": "varies…
hair_care
{"hair_function": "conditioning", "hair_type_suitability": "fine/medium", "curl_pattern_suitability": "all", "porosity_suitability": "low", "protein_sensitivity": "neutral", "moisture_protein_balance": "no", "cg_method_approved": "non-water-soluble", "silicone_type": "not-a-sulfate", "sulfate_type": "no", "drying_alcohol": "no", "fatty_alcohol": "yes", "heat_protectant": "yes", "color_safe": "neut…
pediatric_safety
{"safe_for_newborn_0_6m": "caution", "safe_for_infant_6_12m": "yes", "safe_for_toddler_1_3y": "yes", "safe_for_child_3_12y": "yes", "safe_for_teen_12_18y": "yes", "pediatric_max_concentration_pct": "10.0", "adult_max_concentration_pct": "10.0", "pediatric_dermal_absorption_factor": "minimal", "endocrine_disruption_concern_pediatric": "low", "diaper_area_safe": "yes", "pediatric_allergy_prevalence"…
regulatory
{"eu_status": "allowed", "us_status": "allowed"}
self_tanning
{"cas_number": "540-97-6", "ingredient_class": "spray_tan", "tanning_mechanism": "other", "color_development_onset_hours": "0.0", "full_color_development_hours": "0", "color_duration_days": "0", "DHA_concentration_if_applicable_pct": "0", "erythrulose_concentration_pct": "0", "pH_dependent_color": "no", "formaldehyde_release_concern": "no", "formaldehyde_release_ppm": "0", "AGE_formation_concern":…

Function Categories & List Membership

Cosmetic/Chemical Function Categories
Softener and conditioner Solvent

Expert Verdict

Expert safety assessment and concern-level summary for Cyclohexasiloxane.

Regulatory Flags

svhc vpvb eu-restricted-2026 reach-reg-2024-1328 bioaccumulative environmental-hazard volatile-silicone cyclic-siloxane pops-candidate reformulate-required

Known Synonyms

Cyclohexasiloxane, 2,2,4,4,6,6,8,8,10,10,12,12-dodecamethyl- Cyclohexasiloxane, dodecamethyl- 2,2,4,4,6,6,8,8,10,10,12,12-Dodecamethylcyclohexasiloxane EINECS 208-762-8 UNII-XHK3U310BA DC 246 DC 246 Fluid Dow Corning 246 Dow Corning 246 Fluid Hexadecamethylcyclohexasiloxane SF 1258 SH 246 SH 246 Fluid Xiameter PMX 0246

Chemical Function

Softener and conditioner Solvent

Regulatory Lists

Europe; Other direct contact consumer goods CEDI

Australian Status

AICIS status: listed

Frequently Asked Questions

Is Cyclohexasiloxane safe in cosmetics?

Cyclohexasiloxane has a safety rating of "MODERATE" in our database. EU status: restricted. US status: permitted.

Is Cyclohexasiloxane allowed in the EU?

Cyclohexasiloxane EU regulatory status: restricted. Maximum allowed concentration: ≥0.1% w/w prohibited in all consumer and professional products under EU Reg 2024/1328; enforcement June 6, 2026. This is based on EU Regulation 1223/2009 and its amendments.

What does Cyclohexasiloxane do in cosmetics?

Cyclohexasiloxane functions as: solvent, emollient, volatile carrier. It is classified as a cosmetic ingredient in our database. CAS number: 540-97-6.

Is Cyclohexasiloxane used outside cosmetics?

Cyclohexasiloxane also appears in industrial chemical safety data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.

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