Emollients are ingredients that lend a smooth, soft, or lubricious feeling to skin, and are among the most common materials used in personal care formulations.

Multifunctional benefits

Beyond smoothing and softening, emollients are multifunctional powerhouses that can provide a variety of benefits such as:

• Modify skin feel
• Provide shine to skin, hair, and lips
• Condition hair
• Act as an active solvent
• Thicken anhydrous, oil in water, and water in oil formulations
• Moisturize and improve skin elasticity
• Reduce skin moisture loss
• Can reduce the appearance of wrinkles
• Can increase cell turnover

Emollient chemical types

The most common chemical type, esters are compounds formed by reacting acids with alcohols or polyols. Most natural emollients are triglyceride-based oils formed by reacting Glycerin with fatty acids. Many esters however are not stable at low or high PH and can break down into their starting materials over time.

Fatty alcohols are organic compounds in which a hydroxyl group is attached to a saturated, unsaturated, or branched carbon and the chain length is greater than about seven carbons. Typical fatty alcohols used in formulations include Cetyl, Stearyl, Isostearyl, Oleyl, Octyldodecyl, and Behenyl alcohols.

Fatty acids are mono carboxylic acids having a chain length greater than about seven carbons. Typical fatty acids used include Lauric, Myristic, Palmitic, Stearic, Oleic, Isostearic, Ricinoleic, and Behenic acid.

Ethers are compounds in which an oxygen atom connected to two alkyl or aryl groups and are very stable to low or high PH and oxidizing agents.

Silicones are linear or cyclic polymers of silicone/oxygen monomers. The polymers are made up of alternating silicone and oxygen atoms and may carry end or pendant block groups that can be functionalized. Dimethicone, Cyclopentasiloxane, and Dimethicone/ Dimethicone Crosspolymers are the types mainly used as emollients.

Hydrocarbons are compounds carrying only carbon and hydrogen groups. The main types used include mineral oil, Petrolateum, Squalane, Isododecane, Isohexadecane, Microcrystalline wax, Polyethylene, Ozokerite, and Paraffin wax.

Factors to consider in choosing emollients

• The desired skin or hair benefit
• Skin compatibility, irritation profile
• Polarity
• Spreading characteristics
• Substantivity: important for rinse off products. The structure, molecular weight, and viscosity are the critical factors.
• Impact on foam/lather
• Stability: important for high or low pH formulations and those containing oxidizing or reducing agents.
• Global approval/availability
• Cost

Learn more about emollient technology and see product recommendations in the Prospector Knowledge Center.