a synthetic ester widely used in cosmetic and personal care formulations as a non-greasy emollient and skin-conditioning agent. It imparts a silky, dry-touch feel, improves spreadability, and enhances the sensory profile of creams, lotions, color cosmetics, and sunscreens.

Isotridecyl Isononanoate is a synthetic ester widely used in cosmetic and personal care formulations as a non-greasy emollient and skin-conditioning agent. It imparts a silky, dry-touch feel, improves spreadability, and enhances the sensory profile of creams, lotions, color cosmetics, and sunscreens. Regulatory expert groups—including the EU CosIng database and the Cosmetic Ingredient Review (CIR) Expert Panel—have assessed it as safe for use at concentrations up to 25% in leave-on products, with very low risk of irritation or sensitization. Independent consumer safety databases such as EWG rate it as a low-concern ingredient for cancer, allergies/immunotoxicity, and developmental/reproductive toxicity.

Chemical Identity

• Physical Properties: Clear, colorless liquid; low viscosity; non-oily, “nearly dry” skin feel
  
  

Functions & Benefits

• Emollient: Softens and smoothes the skin surface by forming a lightweight occlusive layer

• Skin Conditioning: Helps maintain skin in good condition, improving pliability and tactile feel

• Moisturizing Agent: Promotes hydration by reducing trans-epidermal water loss

• Formulation Enhancer: Improves spreadability and stability; acts as a silicone oil solubilizer and viscosity modifier in emulsions
  
  

Occurrence & Typical Use Levels

• Present in approximately 0.06% of cosmetic formulations on average, with higher levels (up to ~0.7%) in color cosmetics such as lipsticks

• Recommended Maximum: Up to 25% in leave-on products without irritation; undiluted material may be mildly irritating in animal tests but is generally well tolerated in human patch tests

• Usage Restrictions: Not intended for fragrance or flavor applications
  
  

Safety & Regulatory Status

• CIR Assessment: Included in the “Pelargonic Acid and its Esters” report; concluded safe “as used” in cosmetic practice (no genotoxicity, sensitization, or reproductive toxicity concerns)

• Human Patch Tests: A facial cream with 4.3% Isotridecyl Isononanoate showed no evidence of contact allergy in 28 volunteers

• EWG Score: Rated “Low” for cancer, allergies/immunotoxicity, and developmental/reproductive toxicity

• EU CosIng: Permitted under the general provisions of the Cosmetics Regulation with no specific restrictions

• FDA: While not listed as a direct food additive, its safety in cosmetic formulations is recognized via CIR review; standard Good Manufacturing Practices apply in the U.S.
  
  

Applications in Formulations

• Skin Care: Face and body creams, lightweight lotions, makeup removers

• Color Cosmetics: Foundations, concealers, lipsticks, eye products

• Sun Care: Sunscreen lotions and sprays for improved spreadability

• Hair Care: Conditioners and styling formulations for a smooth, non-greasy finish
  
  

Practical Formulation Tips

• Incorporation: Add near the cool-down phase to preserve sensory properties and avoid excessive volatility loss

• Compatibility: Mixes well with silicones, natural oils, and waxes; may enhance solubility of oil-soluble actives

• Stability: Shows good oxidative stability; recommended use of antioxidants (e.g., tocopherols) in formulations prone to rancidity

Usage: Used in all skin care products.

Mixing method: Mix in the oil. Can withstand heat Can be contained in formulas with a pH in the range of 3-10.

Usage rate: 1-20%

Product characteristics: colorless liquid

Solubility: Can dissolve in oil

Storage: Can be stored at room temperature But close the bottle cap tightly. Then completely protected from sunlight or heat.

INCI Name : Isotridecyl Isononanoate