Octamethylcyclotetrasiloxane
| Names | |
|---|---|
| Preferred IUPAC name
Octamethyl-1,3,5,7,2,4,6,8-tetroxatetrasilocane | |
Other names
| |
| Identifiers | |
3D model (JSmol) |
|
| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.008.307 |
| EC Number |
|
PubChem CID |
|
| UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
| Properties | |
| [(CH3)2SiO]4 | |
| Molar mass | 296.616 g·mol−1 |
| Density | 0.956 g/mL |
| Melting point | 17–18 °C (63–64 °F; 290–291 K) |
| Boiling point | 175–176 °C (347–349 °F; 448–449 K) |
| 56.2±2.5 ppb (23 °C) | |
| log P | 6.98±0.13 |
| Vapor pressure | 124.5±6.2 Pa (25 °C) |
| Hazards | |
| GHS labelling: | |
| Warning | |
| H361f, H410 M=10 | |
| Related compounds | |
Related compounds |
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
Octamethylcyclotetrasiloxane, also called D4, is an organosilicon compound and one of a number of cyclic siloxanes (cyclomethicones). It is a colorless viscous liquid with a high boiling point. It has historically been used on a large scale in personal care products including cosmetics, hair conditioners and emollients (moisturising creams), Global production in 1993 was 136,000 tons, however it is now facing significant pressure from regulators. It is a substance of very high concern In the EU, where it was classified as a PBT and effectively banned in personal care products in 2018. The US EPA began reevaluating its risks in 2020. Replacements include branched-chain alkanes (isoparaffins).