Cyclotetrasiloxane (D4)
Cyclotetrasiloxane chemical properties
CAS Number:
556-67-2
Other Chemical Name:
Formula:
(C2H6OSi)4
Boiling point:
175 °C (347°F)
Flash Point
56°C (133°F)
Density:
Viscosity：
Physical State:
Description & Application
Cyclotetrasiloxane, commonly known as D4, is a cyclic silicone compound with the chemical formula C₈H₂₄O₄Si₄. It’s a clear, odorless liquid with a low viscosity, making it easily spreadable and quick to evaporate. D4 has been widely used in various industries.
Cyclotetrasiloxane is historically used for hair and skin care. However, it use is declining due to environmental concerns.
Regulation - Cyclotetrasiloxane VS Cyclopentasiloxane
| Feature | Cyclotetrasiloxane (D4) | Cyclopentasiloxane (D5) |
|---|---|---|
| Environmental Impact | Higher bioaccumulation potential | Lower bioaccumulation potential, but still persistent |
| Regulatory Status (EU) | Banned in cosmetic products since 2019 | Restricted to 0.1% in all cosmetics (proposed, expected to be in effect in July 2026) |
| Regulatory Status (US) | No specific restrictions | No specific restrictions |
| Prevalence in Formulations | Rare due to ban in the EU | Less common due to environmental concerns and anticipated restrictions |
It’s worth noting that D4 has a freezing point around 17°C (63°F), while D5 has a much lower freezing point of approximately -44°C (-47°F). When the temperature rises above 17°C, D4 will return to its fluid state without any loss of properties.
Product Equivalent
- MOMENTIVE: SF1173
- DOWS: XIAMETER PMX-0244, DOWSIL 244 Fluid
- BRB: CM 40
Synonyms:
Need more information?
Our expert would like to speak with you about your project. Feel free to reach us using the below details.