Octamethylcyclotetrasiloxane

• 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.
• Octamethylcyclotetrasiloxane (OMCTS), a common constituent of household products, triggers the transformation of bismuth to the volatile toxic derivative trimethylbismuth by Methanosarcina barkeri, which is a representative member of the sewage sludge microflora