Cyclotetrasiloxane, octamethyl-
Synonyms
Octamethylcyclotetrasiloxane;
Cyclotetrasiloxane;
Category
Silicone Surfactant
> Non-ionic Silicone Surfactant
>> Cyclic Silicone Polymer
Chemical Numbering System
CAS: 556-67-2
EINECS: 209-136-7
Molecular Formula & Molecular Weight
Molecular Formula: C8H24O4Si4
Molecular Weight: 296.62
Structure
Properties
Appearance (1), liquid.
Solubility insoluble in water.
Physical - chemical properties
|
Melting point, °C |
17.5[1] |
Stability stable.
Risk Liquid form: irritation, irritation to skin, eye, respiratory system.
GHS label: 
Animal Toxicity
Table 1 Animal toxicity values
|
rabbit skin LD50 |
0.794mL/kg[2] |
|
rat inhalation LC50 |
36000mg/m3/4H[2] |
|
rat oral LD50 |
1540mg/kg[2] |
|
rat skin LD50 |
1770mg/kg[2] |
Ecology may be hazardous to environment. Water body should be given special attention.
Biodegradability biodegradable.
Characteristics excellent film-forming, lubricating, dispersing, adsorbing abilities.
Synthesis
Quality Standards & Test Methods
1, Physical and chemical indexes
|
Item |
Physical and chemical indexes |
|
Liquid |
|
|
Actives, %, ≥ |
95.0 |
Test Methods
(1), Actives
2, Hazardous substances indexes
|
Item |
Hazardous substances indexes |
|
Liquid |
|
|
Heavy metals (as Pb), mg/kg, ≤ |
20 |
|
As, mg/kg, ≤ |
3 |
Test Methods
(1), Heavy metals (as Pb)
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30799 The test method of food detergents -- Determination of heavy metals
(2), As
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30797 The test method of food detergents -- Determination of total arsenic
3, Product standards
(1), Chinese standards
(1a), GB/T 20435 Octamethylcyclotetrasiloxane
3, Further explanation
(a), On physical and chemical indexes: firstly, shall be indicated carbon atom distribution; secondly, shall be indicated average molecular weight.
Major Uses
1, Typical applications
Use as film-forming agent.
Use as lubricant.
Use as solvent.
Use as intermediate in organic synthesis.
2, Personal care products
Conditioning agent, emollient, solvent in personal care products.
Further information:
(1), In accordance with EU regulations (EC) 2019/831, be included in Annex II/1388.
Not to be used in personal care products.
3, Textile, fiber, leather
Softening agent, brightening agent in textile, fiber, leather.
Manufacturers
References
[1]: HSDB. 556-67-2, Octamethylcyclotetrasiloxane
[2]: ChemIDplus. 556-67-2, Octamethylcyclotetrasiloxane
Update: 20140828(1); 20200918(2);