A cyclic silicone, listed as an emollient and solvent, linked in EU data to an Annex II entry.
What it is
Cyclotetrasiloxane is octamethylcyclotetrasiloxane, often abbreviated D4, a cyclic siloxane made of four dimethylsiloxane units. CosIng lists it as an emollient and a hair-conditioning and solvent ingredient. The EU data link this ingredient to an entry in Annex II (prohibited substances).
Where it is used
Appears on the ingredient lists of a small number of products.
Limits of interpretation
The INCI list shows which ingredients are present, not how much of each. Above 1%, ingredients are listed in descending order of weight; below 1% the order is free.
See the EU regulation section for what the Annex II entry covers and how it applies. The INCI list does not show whether it was added on purpose or comes from another silicone ingredient.
Functions
- Skin conditioning – emollient
- Acting as lubricants on the skin surface providing the skin with a soft and smooth appearance.
- Hair conditioning
- Enhancing the appearance and feel of hair. Leaving the hair easy to comb, supple, soft and shiny and/or imparting volume, lightness, gloss, texture, etc.
- Solvent
- Dissolving other components of cosmetics. Solvents are usually liquids (aqueous and nonaqueous).
EU regulation
- As of
- 3 November 2026 · (EU) 2019/831
Safety Gate alerts (EU)
2 alerts about dangerous cosmetics in the EU mention this substance. An alert concerns a specific product, usually one that breaks EU rules.
- imago – haircare 2 fasen (2021-01-05)
- CoiffiCare – Coifficare 2 en 1 - restructurant et démélant instantané - Cheveux secs et abîmés (2021-01-05)