Octamethylcyclotetrasiloxane (D4)
Octamethylcyclotetrasiloxane (D4) is an odorless, colorless non-oily silicone fluid used primarily to make other silicone materials. During this manufacturing process, virtually all of the material is consumed, with only a tiny amount of D4 remaining. In a small handful of personal care products, D4 can be used as an additive providing certain application-related benefits preferred by consumers.
D4 is one of the most extensively studied chemicals used in consumer applications. More than 30 studies have been conducted assessing the safety of D4 and the data support that D4 is safe when used as intended.
For more information about the safety and uses of D4, please see the following:
- SEHSC Fact Sheet - Safety of D4
- SEHSC Fact Sheet – D4 Environmental Fate & Effects
- SEHSC Fact Sheet – D4 in Personal Care Products
For more information on the industry’s voluntary health research programs, see Siloxane Research Program.