Cyclomethicone

NCI Name: Cyclomethicone (or specific: Cyclotetrasiloxane, Cyclopentasiloxane, Cyclohexasiloxane)

CAS Number - 69430-24-6

Appearance: Clear to slightly hazy, colorless, odorless liquid

Solubility: Insoluble in water; soluble/miscible with alcohols, many oils, esters, hydrocarbons, and other silicones (except castor oil in some cases).

Volatility: Fully evaporates at room temperature without cooling the skin or leaving residue.

✅In Sunscreens: It prevents UV filters from clumping, ensuring a uniform protective film across the skin, which is vital for achieving the stated SPF and minimizing the dreaded "white cast."

✅Advanced Delivery and Penetration Enhancement

✅In Foundations: It allows pigments to glide evenly, preventing patchiness, settling into pores, or oxidizing unevenly throughout the day.

✅Non-Comedogenic and Hypoallergenic Profile

Because cyclomethicone evaporates rapidly when exposed to heat, it must never be added to the heated water or oil phases during initial emulsification.Cool-Down Phase

Addition: Introduce cyclomethicone only during the final cool-down phase, once the batch temperature has dropped below 40°C (104°F). Adding it at higher temperatures will cause the ingredient to volatilize into the manufacturing environment, altering the final product percentage and wasting raw material.

High-Shear Mixing: While it incorporates easily into cool emulsions, standard moderate agitation is usually sufficient. If using a high-shear homogenizer, keep the processing time brief to minimize friction-induced heat buildup that could trigger evaporation.

Recommended Usage Rates :

Face Creams & Lotions1% – 5%

Hair Serums & Oils-10% – 50%

Primers10% – 30%

Body Oils10% – 50%

Room Sprays & Perfumes - Up to 80%