Cyclopentasiloxane (Decamethylcyclopentasiloxane, D5)-CAS 541-02-6

Cyclopentasiloxane (Decamethylcyclopentasiloxane, D5)-CAS 541-02-6

Cyclopentasiloxane, commonly known as D5, is a widely used volatile cyclic silicone fluid in the cosmetic and personal care industry. Renowned for its exceptional spreading properties, silky skin feel, and controlled volatility, D5 has become a staple ingredient in premium skincare, hair care, and color cosmetic formulations. As a lightweight silicone with low surface tension, it spreads easily and evenly across the skin and hair, leaving a smooth, non-greasy, velvety finish without heavy residue. Its moderate volatility allows it to evaporate gradually at skin temperature, delivering active ingredients effectively while leaving behind a soft, silky after-feel. D5 is also valued for its excellent solubilizing properties for various cosmetic ingredients and its ability to enhance the sensory experience of products, making it a versatile choice for everything from foundations and serums to deodorants and hair conditioners.

Key Benefits

• Excellent spreading: Low surface tension enables easy, even spreading across skin and hair

• Silky skin feel: Leaves skin smooth, soft, and velvety without greasiness or heaviness

• Controlled volatility: Moderate evaporation rate, delivers actives then dissipates without residue

• Non-comedogenic: Does not clog pores, suitable for all skin types including oily and acne-prone

• Enhanced sensory experience: Improves product texture, glide, and overall application feel

• Excellent solubilizer: Dissolves wide range of cosmetic ingredients and active compounds

• Hair conditioning: Reduces frizz, adds shine, improves combability and manageability

• SPF boosting: Enhances sunscreen performance, can increase SPF by 12%–18%

• Low skin penetration: <0.1% transdermal absorption, stays primarily on skin surface

• High purity: Cosmetic grade with D4 content ≤0.1%, meets global safety standards

Applications

• Skin care creams, lotions, and serums: Recommended usage 5%–30% for silky feel and spreading

• Foundations, BB creams, and color cosmetics: Recommended usage 5%–15% for smooth application and finish

• Sunscreens and sun care products: Recommended usage 5%–20% for SPF boosting and elegant texture

• Hair conditioners, hair masks, and hair serums: Recommended usage 1%–10% for conditioning and shine

• Deodorants and antiperspirants: Recommended usage 5%–20% as volatile carrier and emollient

• Lipsticks, lip glosses, and lip care: Recommended usage 3%–15% for smooth application and comfort

• Mascara and eye makeup: Recommended usage 2%–10% for smooth application and wear

• Nail polish and nail care products: Recommended usage 5%–20% as solvent and film modifier

• Perfumes and fragrance products: Recommended usage 2%–15% as fragrance carrier and fixative

• Shaving creams and shaving gels: Recommended usage 3%–10% for smooth glide and skin protection

Certificate Of Analysis (COA)

Frequently Asked Questions (FAQ) 

Q1: What is the difference between D5 and D4 (Octamethylcyclotetrasiloxane)?

A: D5 has 5 silicone units in its ring structure, while D4 has 4. D5 is less volatile, has a higher boiling point, and is considered safer for human health. D4 is classified as CMR Category 2 (suspected reproductive toxicant) under EU regulations, so high-purity D5 strictly controls D4 content to ≤0.1%.

Q2: Is D5 safe for use in cosmetics? What about the EU restrictions?

A: D5 is generally recognized as safe for human health by CIR (up to 15%) and China's cosmetic regulations. The EU restriction (≤0.1% in rinse-off products) is based on environmental bioaccumulation concerns, not human health risks. Leave-on products have no such concentration limit in the EU.

Q3: Does D5 cause acne or clog pores? Is it suitable for oily skin?

A: No, D5 has a comedogenicity rating of 0 (non-comedogenic). It is lightweight and volatile, leaving no heavy residue. It is actually beneficial for oily skin types, providing a matte, silky finish without greasiness or pore-clogging effects.

Q4: What is the recommended usage level and how do I add it?

A: Typical usage ranges from 1%–30% depending on product type. Add directly to the oil phase of formulations. It is compatible with most cosmetic ingredients and works across a wide temperature range. No special handling required beyond standard silicone precautions.

Q5: What compliance documents can you provide?

A: Batch COA, SDS/GHS, Certificate of Origin, China Cosmetic Ingredient Inventory confirmation (No. 03031), technical data sheet, heavy metal and microbiological test reports, D4 content specification. REACH and FDA documentation available upon request.

Q6: How does D5 compare to Dimethicone (linear silicone)?

A: D5 is cyclic and volatile, evaporating completely at skin temperature with no residual build-up. Dimethicone is linear and non-volatile, leaving a longer-lasting protective film. D5 provides lighter, silkier feel and better spreading, while dimethicone offers longer-lasting conditioning and protection. They are often used together for synergistic effects.

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