Ingredient profile
Cyclotetrasiloxane
Raters disagreeemollienthair conditioningsolventCAS 556-67-2CAS 293-51-6
At least one of our safety lists speaks to this ingredient. Also written as CYCLOTETRASILOXANE, cyclotetrasiloxane.
Raters don't agree. Here's where each one stands
Safe
—
Caution
EU Harmonised Classification (CLP Annex VI)
Government
Concern
Greenlens Ingredient Scan
Independent
Greenlens Precautionary Screen
Independent
Greenlens Tolerance Screen
Independent
ANSES Endocrine Disruptors
Government
Where each list lands
Funding shown- Concern
Greenlens Ingredient Scan
Independent
Listed in Annex II of the EU Cosmetics Regulation (ref 1388) — prohibited as an ingredient in cosmetic products. (EU Cosmetics Regulation Annex II (prohibited))
- Concern
Greenlens Precautionary Screen
Independent
A silicone classified as an endocrine disruptor and reproductive toxicant in the EU. (EU CLP Annex VI (CMR classification); ChemSec SIN List (Substitute It Now))
- Concern
Also screened — not on these lists
- Health Canada Ingredient Hotlist
- California Proposition 65
- US NTP Report on Carcinogens
- IARC Monographs
- EU Microplastics Restriction
Where regulators stand
Shown side by side, never combinedEach jurisdiction is reported on its own terms, from its own official lists. Where they disagree, that disagreement is the finding. Absence from a list is never a safety claim.
European Union
BannedProhibited as a cosmetic ingredient in this jurisdiction.
- European Commission · EU Cosmetics Regulation Annex II (prohibited)Listed in Annex II of the EU Cosmetics Regulation (ref 1388) — prohibited as an ingredient in cosmetic products.
- ECHA (EU CLP Regulation) · EU CLP Regulation Annex VI, Table 3 (harmonised classification, ECHA export): Repr. 2Carries an EU harmonised classification (Repr. 2) — a suspected (category 2) carcinogen, mutagen or reproductive toxicant under CLP Annex VI, index 014-018-00-1. A hazard classification, not proof of harm at the level used.
- ECHA (REACH) · ECHA Candidate List of Substances of Very High Concern (REACH)A cyclic silicone used in hair and skin products, identified as persistent, bioaccumulative and toxic (PBT/vPvB).
Canada
No listing found
Notes
- EU-prohibited
- ANSES-prohibited in cosmetics
- Endocrine-active
- EU harmonised CMR (cat. 2)
