Ingredient Dictionary

DISILOXANE

Hexamethyldisiloxane is an organosiloxane consisting of two trimethylsilyl groups covalently bound to a central oxygen.

How much products actually contain

No product states its amount yet.

Of the products containing it, 81 list it before the 1% line and 4 after it (usually 1% or less).

Products using this ingredient

12 of 84 confirmed · likeliest to carry enough first · See all 84

Definition

Hexamethyldisiloxane is an organosiloxane consisting of two trimethylsilyl groups covalently bound to a central oxygen.

Source: PubChem

US FDA substance register · UNII D7M4659BPU · registered name Hexamethyldisiloxane · single chemical substance

Source: US FDA Unique Ingredient Identifier (UNII)

Disiloxane is the linear siloxane that conforms to the formula

Cosmetic roles

Removes unwanted foamANTIFOAMINGSkin conditioning not covered aboveSKIN CONDITIONING - MISCELLANEOUS

Safety & regulatory references

Korea’s toxic-substance GHS classification: Danger · H400 (category 1) · H410 (category 1) · H225 (category 2)

Source: Korea toxic substances GHS register (NIER)

More data — names, identifiers, properties, test records, literature

Official labels & definitions

JCIA labelling name ジシロキサン: 本品は、次の化学式で表される直鎖状シロキサンである。

Source: JCIA labelling names (Japan)

Names & identifiers

DISILOXANEINCI다이실록세인Korean label name (MFDS standard)Disiloxane, hexamethyl-SynonymジシロキサンJapanese labelling name

CAS No.chemical registry number: 107-46-0
EC No.EU chemical inventory number: 203-492-7
DTXSIDUS EPA chemical ID: DTXSID4026769
DTXCIDUS EPA compound ID: DTXCID406769

IUPAC: Hexamethyldisiloxane
Molecular formula: C6H18OSi2
Molecular weight: 162.379 g/mol

Measured properties

Appearance: Liquid, Other Solid, CBI, Dry Powder · Liquid, [HSDB] Colorless liquid, [MSDSonline]
Boiling point: 99 °C · 101 °C @760 [mm Hg]
Melting point: -66 °C · -59 °C
Solubility: In water, 0.93 mg/L at 25 °C · 0.93 mg/L @ 25 °C (exp)
Density: 0.7638 at 20 °C · 0.76 @ 20°C
Viscosity: 0.51 centistokes at 20 °C · 0.488 cP (25 C)
Colour: colourless
Odour: odourless
Melting/freezing point: -67 ℃
Initial boiling point and range: 100 ℃
Flash point: -3 ℃
Upper/lower flammability or explosive limits: 21.8 / 0.5 %
Vapour pressure: 42.1 ㎜Hg (at 25℃(est.))
Water solubility: 0.93 ㎎/ℓ
Relative density: 0.8
n-Octanol/water partition coefficient (Kow): 4.20
Auto-ignition temperature: 340 ℃
Molecular weight: 162.44

Values measured on the substance itself. The KOSHA data are a reference for writing and reviewing safety data sheets, not a specification for a commercial raw material.

Source: PubChem · KOSHA safety data sheets (Korea)

What products actually use it for

What the 20 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.

Degradant/impurity (EPA)3
Intermediate3
Solvent2
Diluent2
Insulators2
Cleaning agent1
Monomers1
Viscosity modifier1

5 other uses

Terminator/blocker1
Lubricating agent1
Processing aids not otherwise specified1
Anti-adhesive/cohesive1
Surfactant (surface active agent)1

Source: US EPA CompTox dashboard

Irritation and sensitisation studies

8 skin studies and 3 eye studies are on record.

Classed as low7

The study conclusions largely agree (100%). These tests are on the raw material itself; irritation at the amount in a finished product is a different question.

See all 11 studies

Classification not possible
Skin Sensitization · Screening
Not likely to be sensitizing
skin sensitisation: in vivo (non-LLNA) · Screening · according to OECD Guideline 406 (Skin Sensitisation)
Studies Indicate No Significant Irritation
skin irritation: in vivo · Screening · OECD Guideline 404 (Acute Dermal Irritation / Corrosion) equivalent or similar to
Not classified
Skin Irritation · Screening
Studies Indicate No Significant Irritation
skin irritation: in vivo · Screening · other guideline: modified methods of CTFA Safety Testing Guidelines, published by the Cosmetic, Toiletry and Fragrancy Association on September 27, 1985, and Preclinical Safety Evaluation of Materials used in Medical Devices HIMA Report 85-1. according to
Studies Indicate No Significant Irritation
skin irritation: in vivo · Screening · other guideline: CTFA Guideline, Sept. 27, 1985 according to
Studies Indicate No Significant Irritation
skin irritation: in vivo · Screening · other guideline: Hazardous Substances Labelling Act, Part 191.11, Ch.1, Title 21 according to
Studies Indicate No Significant Irritation
skin irritation: in vivo · Screening · OECD Guideline 404 (Acute Dermal Irritation / Corrosion) no guideline followed
Not classified
Eye Irritation · Screening
Studies Indicate No Significant Irritation
eye irritation: in vivo · Screening · other guideline: CFR 191.12 Ch Title 21 according to
Studies Indicate No Significant Irritation
eye irritation: in vivo · Screening · OECD Guideline 405 (Acute Eye Irritation / Corrosion) equivalent or similar to