Cyclotetrasiloxane
Irritancy: unknownComedogenicity: unknownEmollient
The details
This ingredient is a small silicone made to be silky and weightless. It works as an emollient and solvent for heavier pigments/silicones as well. According to the CIR Expert Panel, this ingredient is considered gentle and doesn't penetrate deeply into skin. The EU and UK have banned this ingredient in cosmetics since 2020. A separate EU REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals) rule caps D4 as a trace impurity at under 0.1% in any cosmetic. In September of 2025, the US EPA's draft TSCA risk evaluation that came out in September 2025 preliminarily found D4 poses "unreasonable risk to human health and the environment". This could lead to restrictions in the next year or so.
Found in (1 products)
Also listed as
cyclotetrasiloxane