Functional Roles
Industries Served
Physical Properties
melting_point
17.5 u00b0C
boiling_point
175 u00b0C
density
Specific gravity: 0.9558
solubility
In water, 0.056 mg/L at 23 u00b0C
vapor_pressure
1.05 [mmHg]
flash_point
55 u00b0C (131 u00b0F) - closed cup
GHS / SDS Safety
Warning
Environmental Hazard
Health Hazard
Flammable
- H226: Flammable liquid and vapor [Warning Flammable liquids]
- H361 (96%): Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]
- H413 (89.7%): May cause long lasting harmful effects to aquatic life [Hazardous to the aquatic environment, long-term hazard]
- H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]
- H361f: Suspected of damaging fertility [Warning Reproductive toxicity]
- H413: May cause long lasting harmful effects to aquatic life [Hazardous to the aquatic environment, long-term hazard]
- H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]
- H361f ***: Suspected of damaging fertility [Warning Reproductive toxicity]
- H226 (72.1%): Flammable liquid and vapor [Warning Flammable liquids]
Chemical Identity
| CAS Number | 556-67-2 |
| IUPAC Name | 2,2,4,4,6,6,8,8-octamethyl-1,3,5,7,2,4,6,8-tetraoxatetrasilocane |
| InChI Key | HMMGMWAXVFQUOA-UHFFFAOYSA-N |
| PubChem CID | 11169 |
| INCI Name | CYCLOTETRASILOXANE |
Synonyms & Trade Names
Full Description
Cyclotetrasiloxane (D4) is a cyclic siloxane consisting of four repeating dimethylsiloxane units arranged in a ring. It is primarily used as an intermediate in the production of PDMS and other silicone polymers, and as a specialty solvent in industrial formulations. D4 is classified as an SVHC in the EU and restricted under REACH as a PBT/vPvB substance, with restrictions in rinse-off cosmetics above 0.1%.