CYCLOMETHICONE
Commonly Found In
Overview
Cyclomethicone is a mixture of cyclic siloxanes (primarily D4 and D5) used as a lightweight, fast-evaporating silicone in cosmetics. It imparts a smooth, non-greasy skin feel and is used in primers, serums, and antiperspirants. The EU restricts D4 to below 0.1% in leave-on products due to environmental persistence and aquatic toxicity concerns. D5 is restricted to below 0.1% in wash-off products.
Also known as: cyclic dimethylsiloxane, D4 (octamethylcyclotetrasiloxane), D5 (decamethylcyclopentasiloxane), D6 (dodecamethylcyclohexasiloxane)
Key Benefits
Studies suggest cyclomethicone provides a smooth, lightweight skin feel, improves spreadability of formulations, and reduces tackiness without clogging pores. Evaporates from skin surface, leaving conditioning film components behind.
Supporting Research
- β’ Cosmetic ingredient literature: D4/D5 reviewed by CIR as safe for skin use at cosmetic concentrations
- β’ EU ECHA assessment (2018): D4 and D5 classified as PBT/vPvB substances (environmental persistence); drove EU restrictions
Skin Compatibility Ratings
Comedogenic Rating
Non-comedogenic; evaporates from skin surface without clogging pores
Source: CIR Expert Panel; published literature
Irritancy Rating
Low irritancy; well tolerated on skin at cosmetic concentrations
Source: CIR Expert Panel
Typical Use Concentration
Range
0.5β30% (outside EU leave-on restriction)
Optimal
5β15%
EU: D4 max <0.1% in leave-on (effectively banned); D5 max <0.1% in rinse-off. Japan and US: no specific cosmetic concentration limits.
Works Well With / Avoid
Works Well With
EU restricts D4 to <0.1% in leave-on products (environmental/PBT concern); D5 restricted <0.1% in rinse-off. Japan and US allow broader use. Excellent solvent for other silicones and lipophilic actives.
Commonly Found In
Global Regulation Summary
Overview of current status across major international markets.
Detailed Regional Status
| Region | Status | Max Conc. | Conditions | Source |
|---|---|---|---|---|
| πͺπΊ EU | Banned | - | - | Official β |
| πΊπΈ USA | Allowed | - | - | Official β |
| π―π΅ Japan | Allowed | - | - | Official β |
| π°π· Korea | Unknown | - | - | Official β |
| π¬π§ UK | Banned | - | Follows EU regulations (II/1388 (Only when Cyclomethicone contains D4)) | Official β |
π Why Regulations Differ
EU restrictions on D4 and D5 are driven by environmental PBT/vPvB (persistent, bioaccumulative, toxic) classification, not safety-to-humans concerns. Japan and US have not adopted equivalent environmental-driven restrictions in cosmetics. The human safety profile of cyclomethicone is considered acceptable by CIR.
Recent Regulatory Changes
- β’ EU Regulation 2018/1139: D4 restricted to <0.1% in rinse-off and leave-on effective January 2020
- β’ EU Regulation 2020/1182: Extended restrictions for D5 in rinse-off cosmetics
Regulation Analysis
Regional Agreement
Banned in EU, UK but allowed in USA, Japan.
Category Comparison
There are 174 ingredients in the HAIR CONDITIONING category. 99% are banned in at least one major market.
Strictness Ranking
πΏ Natural Sources
Synthetic mixture of cyclic siloxanes (D4 and D5). Does not occur naturally.
π How It's Made
Mixture of D4 and D5 produced through hydrolysis and cyclization of dimethyldichlorosilane.
π Uses in Cosmetics
A lightweight silicone used in hair serums and makeup primers that evaporates quickly without leaving a greasy residue. The EU restricted it in leave-on products (those not washed off) to 0.1% since 2020.
π¬ Other Applications
Dry cleaning solvent and silicone polymer intermediate.
Related Skin Concerns
Data Sources
- β’ EU Regulation 2018/1139 and 2020/1182 β D4/D5 restrictions
- β’ EU ECHA PBT/vPvB assessment for D4 and D5
- β’ CIR Expert Panel β Safety Assessment of Cyclomethicone
Last data verification: 2026-04-12
Related Ingredients
CYCLOTETRASILOXANE
CATALASE
DIBUTYL PHTHALATE
DICHLOROMETHANE
DIETHYLHEXYL PHTHALATE
HYDROLYZED HAIR KERATIN
Learn More
Frequently Asked Questions
Why is CYCLOMETHICONE banned in the EU but allowed in the US?
The EU follows a precautionary principle, banning CYCLOMETHICONE under II/1388 (Only when Cyclomethicone contains D4) due to potential safety concerns. The US FDA has not found sufficient evidence to prohibit its use, allowing it under different safety assessment standards. This reflects differing regulatory philosophies between the two regions.
Why is CYCLOMETHICONE banned in the EU but allowed in Japan?
The EU prohibits CYCLOMETHICONE (II/1388 (Only when Cyclomethicone contains D4)) based on their strict safety criteria. Japan's Ministry of Health, Labour and Welfare (MHLW) has evaluated the ingredient and permits its use, potentially with different safety data or usage conditions.
What is CYCLOMETHICONE used for in cosmetics?
CYCLOMETHICONE is primarily used for hair conditioning in cosmetic products. It also serves as skin conditioning - emollient, solvent. The ingredient is commonly found in various cosmetic and personal care products.
Which countries regulate CYCLOMETHICONE?
CYCLOMETHICONE is banned in EU, UK. The ingredient is freely allowed in JP, US.
Are there alternatives to CYCLOMETHICONE?
Due to regulatory restrictions on CYCLOMETHICONE, cosmetic manufacturers often use alternative ingredients with similar functions. For hair conditioning, alternatives may include other approved ingredients in the same category. Consult product labels for specific formulations, and look for products compliant with your region's regulations.
Disclaimer
The information on this website is for educational and informational purposes only and is not intended as medical advice. While we strive for accuracy based on official government databases, cosmetic regulations change frequently. Always consult with a qualified professional or refer to the latest official regulatory documents for compliance. We are not responsible for any actions taken based on the information provided here.