Beauty ingredient · Silicone
Cyclotetrasiloxane (D4)
- CAS
- 556-67-2
A volatile cyclic silicone restricted in the EU and banned in California cosmetics from 2027.
- Cyclic silicone (D4/D5/D6)
- Silicone
- Expert review pending
Concern level
A regulatory warning or restriction somewhere, or strong evidence of harm at typical intake. The concern level sets how many points Cyclotetrasiloxane (D4) costs on a product’s receipt.
What the evidence says
-
Very persistent in the environmentRegulatory
Restricted in the EU (0.1%) in wash-off cosmetics since 2020 and in other cosmetics from 6 June 2027 because they persist and build up in the environment. [1][2]
Evidence tiers say how sure the evidence is, separately from how much it matters. About evidence tiers.
Rules around the world
| Where | Status | Details | Date | Source |
|---|---|---|---|---|
| European Union | Restricted | Below 0.1% in wash-off cosmetics since 31 January 2020; in all other cosmetics after 6 June 2027. | — | [2] |
| California (US) | Banned | Not allowed in cosmetics from January 1, 2027 (AB 496). | From Jan 1, 2027 | [3] |
“Banned” means explicitly prohibited or withdrawn after review; “not permitted” means never authorized there. We use each regulator’s own words.
Names GoodSwap recognizes on labels (4)
- d4
- cyclotetrasiloxane
- cyclotetrasiloxane d4
- octamethylcyclotetrasiloxane
Sources
-
“Shall not be placed on the market in wash-off cosmetic products in a concentration equal to or greater than 0,1 % by weight of either substance, after 31 January 2020.”
eur-lex.europa.eu
-
“for all cosmetic products other than the ones mentioned in paragraph 3(a), paragraph 1 shall apply after 6 June 2027”
eur-lex.europa.eu
-
California AB 496 (2023), Cosmetic safety (amends Health and Safety Code §108980)
“Commencing January 1, 2027, no person or entity shall manufacture, sell, deliver, hold, or offer for sale in commerce any cosmetic product that contains any of the following intentionally added ingredients”
leginfo.legislature.ca.gov